National Curriculum 2023 - Chemistry Curriculum Guide
GRADE 9-10
Domain: Chemical Foundation
Topic: Fundamental Concepts in Chemistry
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Standard: Students should be able to: Describe the nature of matter and its properties, including physical and chemical properties. Identify the branches of chemistry and explain the interdisciplinary relationships between chemistry and other sciences. Discuss the importance of chemistry in daily life and the role of chemists in society. Convert units and numbers in standard or scientific notation
Benchmark I: Students can
explain the fundamental concepts and definitions of chemistry, including the
nature of matter and its composition, chemical elements, and chemical
compounds. |
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Student Learning Outcomes Introduction to Chemistry 1 Describe chemistry as study of properties, reactions and behavior of matter and use of those substance to create new ones. 2 Recognize that people who study chemistry are called chemists 3 Explain that chemistry has many subfields and involves interdisciplinary fields. Students should be able to recognize the following broad subfields with their examples (definitions are not required, an understanding should be developed) - Analytical chemistry - Biochemistry - Inorganic chemistry - Organic chemistry - Neurochemistry - Nucleur chemistry - Physical Chemistry - Theoretical Chemistry Interdisciplinary fields may include agrochemistry, cosmochemistry, envioronmental chemistry, molecular biology, organnometallic chemistry, nanotechnology and pharmacology. 4 Identify applications of sub-disciplines of chemistry such as nanochemistry, cosmochemistry in drug delivery, genetic engineering, electronics, catalysis
Units 1 Understand that units are standardized for better communication and collaboration. 2 Be familiar with SI units especially mass, time and amount of matter 3 Understand that units can be combined with terms for magnitude especially kilo, deci, and milli 4 Understand that chemists use cm3, g and s as more practical units when working with small amounts in lab 5 Understand that errors are inherent part of measurement, and we can manage precision and accuracy with better tools and techniques
Scientific Notation/Standard Form 1 use the standard form A × 10^n where n is a positive or negative integer, and 1 ⩽ A < 10 2 Convert numbers into and out of standard form. 3 Calculate with values in standard form. |
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Knowledge: Students will know… ● The definition of chemistry, the line of study it is related to and the interdisciplinary fields of this science. ● The conversion of numbers to scientific notation and the use of several prefixes. ● Different subfields of chemistry and their domains. Students will understand… ● Terms like Matter, Energy, Units, and Scientific Notation. |
Skills: Students will be able to… ● Express the physical world in terms of matter and its composition. ● Distinguish between different states of matter and their involvement in daily life. ● Identify various elements of daily use and imagine their applications. ●
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Perspectives ● Industrial Applications: Explore how different branches of chemistry, such as organic chemistry, inorganic chemistry, and physical chemistry, are applied in various industries, such as pharmaceuticals, materials science, and energy. For example, in Pakistan, the pharmaceutical industry heavily relies on organic chemistry to synthesize new drugs and the energy sector relies on inorganic chemistry to improve fuel efficiency. ● Historical Development: Trace the historical development of each branch of chemistry and how it evolved over time. For instance, physical chemistry originated in the late 19th century and was heavily influenced by the development of thermodynamics, whereas biochemistry only became a separate branch of chemistry in the early 20th century with the discovery of DNA. ● Interdisciplinary Nature: Emphasize the interdisciplinary nature of chemistry and how branches of chemistry overlap and interact with each other and with other sciences such as biology, physics, and engineering. For example, physical chemistry provides the foundation for understanding the behavior of biological molecules, and biochemistry builds upon the principles of organic chemistry. ● The Importance of Units in Scientific Measurements: Understanding the importance of having a standardized system of units for chemical measurements is crucial for accurate communication in the scientific community. In the context of Pakistan, it's important for students to understand the use of units in industrial processes, such as the production of fertilizer, textiles, and pharmaceuticals, and the role that accurate measurements play in the quality control of these products. ● The Historical Development of Units: Throughout history, different civilizations have used different systems of units for measurements, such as the Egyptian cubit or the Roman foot. Understanding the evolution of these systems and the need for a standardized system highlights the role of science in shaping our understanding of the world and the importance of accurate measurements in scientific advancement. ● The Role of Scientific Notation in Chemical Calculations: Scientific notation is a useful tool for expressing very large or very small numbers in a concise and readable manner. In the context of chemistry, this can be used to represent the amount of a chemical substance, the concentration of a solution, or the energy of a chemical reaction. Understanding the importance of scientific notation helps students to accurately perform calculations and interpret data in chemistry experiments. |
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Learning Activities
Exploring the Nature of Matter
Objectives: Describe the nature of matter and its properties, including physical and chemical properties Identify the branches of chemistry and explain the interdisciplinary relationships between chemistry and other sciences Discuss the importance of chemistry in daily life and the role of chemists in society Convert units and numbers in standard or scientific notation
Whiteboard and markers Measuring tools such as graduated cylinders, balances, thermometers, etc. A selection of common household items (examples: sugar, vinegar, baking soda, salt, oil, etc.) Lab notebooks and pens A periodic table A reference guide for unit conversion
Introduction: Begin the activity by having students brainstorm a list of common substances they interact with in daily life Write their responses on the whiteboard Ask students to categorize the substances into physical and chemical properties Discuss the definitions of physical and chemical properties and give examples for each category.
Experiment: Provide each student with a set of common household items Ask students to perform a set of physical tests on the items, such as measuring the density, melting point, boiling point, and solubility. Have students record their observations in their lab notebooks.
Conclusion: Review the objectives of the activity and discuss the key takeaways. Encourage students to continue exploring the nature of matter and the importance of chemistry in their daily lives.
Assessment: Evaluate students based on their participation in the activity, lab notebook entries, and ability to convert units and numbers.
References: "Chemistry: The Central Science" by Brown, LeMay, Bursten, and Burdge "Chemistry: An Atoms First Approach" by Zumdahl and Zumdahl "Chemistry: A Molecular Approach" by Nivaldo J. Tro "Chemistry: Structure and Properties" by Richard H. Langley
Real World Unit Conversion Challenge
Objective: To engage higher level thinking skills by having students apply their knowledge of unit conversion to real-world problems.
Materials: ● Metric conversion chart or calculator ● Several real-world problems related to unit conversion (examples below)
Instructions: ● Divide the class into small groups of 2-3 students. ● Give each group a set of real-world problems related to unit conversion. ● Allow the students to work together to solve the problems, using their metric conversion chart or calculator as needed. ● After a set amount of time, have each group present their solutions to the class, discussing the process they used to arrive at their answers. ● Encourage class discussion and critical thinking by asking questions such as "Why did you choose that method?" or "What other methods could you have used?"
Examples of Real-World Problems: ● Convert 5 gallons of gasoline to liters. ● A car travels 50 miles on 6 gallons of gasoline. What is the car's miles per gallon (mpg) rating? ● A swimming pool holds 20,000 gallons of water. How many liters is this? ● The speed limit on a certain road is 65 miles per hour. What is this speed in kilometers per hour? ● A person has a fever of 100°F. Convert this temperature to degrees Celsius. Assessment: Observe the students' problem-solving process and the accuracy of their answers. Have the students write a reflection on their learning, discussing what they learned about unit conversion and their problem-solving strategies.
Introduction to the Fundamentals of Chemistry
Objective: To introduce students to the basic concepts and principles of chemistry, including atomic structure, chemical bonds, and chemical reactions.
Materials: ● Plastic containers with lids (at least 2) ● Measuring cups ● Measuring spoons ● Baking soda ● Vinegar ● Food coloring ● Balloon ● String ● Masking tape
Procedure: ● Fill one of the plastic containers with a mixture of 1/2 cup of baking soda and 1/4 cup of water. ● Add a few drops of food coloring to the mixture and stir until it is well mixed. ● Fill the second container with a mixture of 1/2 cup of vinegar and 1/4 cup of water. ● Stretch a balloon over the opening of the container with the baking soda mixture and secure it in place using a string and masking tape. ● Slowly pour the vinegar mixture into the container with the baking soda mixture, taking care to observe the balloon. ● Discuss the observations with students and ask them to explain what is happening. ● Introduce the concepts of chemical reactions and atomic structure, explaining that the reaction between the baking soda and vinegar is a classic example of a chemical reaction. ● Explain that chemical reactions involve the rearrangement of atoms to form new compounds, and that this reaction results in the release of carbon dioxide gas, which is observed as the balloon expanding.
Explanation: This activity is a simple and engaging way to introduce students to the fundamental concepts of chemistry, including chemical reactions, atomic structure, and chemical bonds. By observing the reaction between baking soda and vinegar, students can see first-hand how chemical reactions can result in the release of gases, changes in temperature, and the formation of new substances. This activity is also an effective way to introduce students to the importance of conducting experiments and making observations, which are essential skills in the study of chemistry.
Reference: Zumdahl, S. S., & Zumdahl, S. A. (2017). Chemical principles. Cengage Learning.
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Domain: Organic
Chemistry
Topic: Basics of organic chemistry
Domain: Biochemistry
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Standard: Students should be able to: Describe the structure and properties of carbohydrates, proteins, and lipids, including their classification as monosaccharides, disaccharides, polysaccharides, amino acids, peptides, and fatty acids. Explain the metabolic pathways and functions of carbohydrates, proteins, and lipids in living organisms, including energy storage and transfer, structural support, and regulatory roles. Describe the structure and function of DNA and RNA, including the role of DNA in genetics and the mechanism of transcription and translation. Discuss the importance of vitamins and minerals in human nutrition, including their role in metabolic processes and the consequences of deficiencies. Apply the concepts of biochemistry to understand the molecular basis of biological processes, diseases, and treatments.
Benchmark I: Identify and draw
the structure and function of carbohydrates, proteins, fats, DNA and vitamins
in biological systems. |
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Student Learning Outcomes 1 Describe proteins as natural polyamides and that they are formed from amino acid monomers with the general structure 2 Describe and draw the structure of proteins 3 Explain the sources, use and structure of proteins, lipids and carbohydrates 4 Describe the importance of nucleic acids 5 Describe and explain vitamins, their sources and their importance to health 6 Identify applications of biochemistry in testing (blood test, pregnancy test, cancer screening, parental genetic testing), genetic engineering, gene therapy and cloning |
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Knowledge: Students will know… ● The differences between the four major biomolecules. ● The sources and use of different biomolecules in the body. ● The applications of biology in healthcare and industries. Students will understand… ● Terms like Nucleic Acids, Lipids, Vitamins, Carbohydrates, and Proteins. |
Skills: Students will be able to… ● Describe the structures of different biomolecules and their composition. ● Identify the different sources of food that these biomolecules are obtained from. ● Explain how different biomolecules are stored inside our bodies and how energy is extracted from them.
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Perspectives ● Biochemistry is the study of the chemical processes that occur within living organisms, and it is a fundamental part of understanding how living things work. ● The structure and properties of carbohydrates, proteins, and lipids play a critical role in the functions and metabolic processes of living organisms. ● Understanding the role of DNA and RNA in genetics and cellular processes is crucial for comprehending how living organisms function and evolve. ● Vitamins and minerals play a vital role in maintaining health and wellbeing, and their deficiencies can have significant impacts on human biology. ● The application of biochemistry has significant implications for medicine and biotechnology, providing insights into disease processes and enabling the development of new treatments. |
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Learning Activities
Exploring the Properties of Proteins
Objective: To understand the properties of proteins and how they can be affected by changes in temperature, pH, and other conditions.
Materials: ● 4 test tubes ● 4 mL of egg white (or another protein solution) ● 4 mL of distilled water ● 1 mL of 1 M HCl ● 1 mL of 1 M NaOH ● Bunsen burner or hot plate ● Test tube holder ● Graduated cylinder
Procedure: ● Label four test tubes as T1, T2, T3, and T4. ● Fill T1 with 4 mL of egg white. ● Fill T2 with 4 mL of distilled water. ● Fill T3 with 4 mL of egg white and 1 mL of 1 M HCl. ● Fill T4 with 4 mL of egg white and 1 mL of 1 M NaOH. ● Use a Bunsen burner or hot plate to gently heat T1 until it reaches 70-80°C. Keep T2, T3, and T4 at room temperature. ● Observe and record any changes in the appearance of the solutions in each test tube. ● Compare the results of each test tube to the original solution in T1.
Sample Results: ● T1 (original egg white solution): A clear, viscous solution with a slightly opaque appearance. ● T2 (distilled water): A clear, colorless solution with no change in appearance. ● T3 (egg white + HCl): The solution may become cloudy or form a precipitate, indicating that the protein has denatured due to the change in pH caused by the addition of HCl. ● T4 (egg white + NaOH): The solution may become clearer or less viscous, indicating that the protein has denatured due to the change in pH caused by the addition of NaOH.
This activity helps students understand the properties of proteins and how they can be affected by changes in temperature, pH, and other conditions. By observing and recording the changes in the appearance of the solutions, students are able to understand the concept of denaturation and the role of pH in protein structure and function.
Lipid Extraction and Analysis Objectives: To extract lipids from a food source and identify their chemical structure To understand the role of lipids in biological systems Materials: ● Vegetable oil ● Ethanol ● Sodium hydroxide ● Beaker ● Test tubes ● Hot plate or Bunsen burner ● Dropper ● TLC (Thin Layer Chromatography) plate ● Solvent (such as hexane and ether) ● Ruler ● Pencil ● Spot plate Procedure: ● Place about 10 mL of vegetable oil in a test tube and add 1 mL of sodium hydroxide solution. Shake the test tube to mix the two liquids. ● Slowly add ethanol to the test tube while swirling the mixture. You will notice a solid material precipitating out of the solution. This is the lipid that you will extract. ● Filter the mixture using a filter paper or funnel. Collect the solid material in a spot plate. ● Using a TLC plate, spot a small amount of the extracted lipid and a known lipid (such as olive oil) onto the plate. ● Develop the TLC plate by placing it in a solvent system (such as hexane and ether). As the solvent moves up the plate, the lipids will separate and migrate up the plate. ● Observe the position of the spots on the TLC plate and measure the distance each spot has traveled. This will give you an idea of the chemical structure of the lipids. ● Compare the distance travelled by the unknown lipid with the known lipid. Based on the distance travelled, you can make an educated guess as to the type of lipid extracted from the vegetable oil. ● Repeat the procedure using different food sources and compare the results. ● Discuss the role of lipids in biological systems, such as the role of fats in energy storage and membrane structure.
References:
"Lipid Analysis - Thin Layer Chromatography." ScienceDirect Topics, Elsevier, www.sciencedirect.com/topics/chemistry/lipid-analysis-thin-layer-chromatography.
"Thin Layer Chromatography of Lipids." Bitesize Bio, bitesizebio.com/11673/thin-layer-chromatography-of-lipids/.
This activity provides hands-on experience in lipid extraction and analysis, and helps students understand the role of lipids in biological systems. In schools where TLC plates may not be available, teachers can use an activity to make nylon instead.
Demonstrating the Insulating Properties of Lipids Using Metal Rods
Objective: To demonstrate how lipids function as thermal insulators by measuring the temperature change of metal rods covered in lipid substances.
Materials: ● 2 metal rods with the same diameter ● Cooking oil ● Shortening or margarine ● Water ● Thermometer ● Beaker ● Heat source (e.g. hot plate or stove)
Procedure: ● Measure the initial temperature of both metal rods using the thermometer. Record the temperature in your lab notebook. ● Place one metal rod into a beaker filled with water and heat the beaker using a heat source until the temperature of the water reaches 50°C. ● Quickly remove the metal rod from the hot water and measure its temperature again using the thermometer. Record the temperature in your lab notebook. ● Repeat steps 2 and 3 with the second metal rod, but this time, cover the rod with a thin layer of cooking oil or shortening/margarine before heating it in the beaker of hot water. ● Measure the temperature of the second metal rod after heating and record the temperature in your lab notebook.
Data Analysis: ● Calculate the temperature change for both metal rods by subtracting the initial temperature from the final temperature. ● Compare the temperature change of the two metal rods.
Expected Results: The metal rod covered in lipid substances (cooking oil or shortening/margarine) should experience a smaller temperature change compared to the metal rod without any lipid covering. This demonstrates that lipids are effective thermal insulators, as they slow down the transfer of heat from the metal rod to the surrounding water.
Conclusion: The experiment shows how lipids function as thermal insulators, which is important for maintaining the temperature stability of living organisms. Lipids play a crucial role in protecting the body from extreme temperature changes and maintaining the internal temperature of cells and tissues.
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GRADE 11-12
Domain: Atomic Structure
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Standard: Students should be able to: Describe the structure of atoms, including the nucleus and electron shells. Explain the concept of atomic number and its relationship to the number of protons in an atom. Describe the arrangement of electrons in the electron shells and explain how this arrangement affects the chemical properties of an atom. Discuss the principles of isotopes, including atomic mass and isotopic abundance. Explain the concept of ionization and describe the formation of ions.
Benchmark I: Students can
describe the structure of atoms, including the protons, neutrons, and
electrons. |
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Student Learning Outcomes 1. Describe the structure of atom as a central positively charged nucleus surrounded by negatively charged cloud of electrons due to electrostatic attraction - understand that, unlike orbits, shells and subshells are energy levels of electrons and a bigger shell implies greater energy and average distance from nucleus - electrons are quantum particles with probabilistic paths whose exact paths and locations cannot be mapped (with reference to the uncertainty principle) - nucleus is made of protons and neutrons held together by strong force - understand that atomic model is a model to aid understanding and if an atom were to be 'photographed' it will be a fuzzy cloud 2. Identify and describe protons, neutrons and electrons in terms of their relative charges and relative masses 3. Understand the terms atomic and proton number; mass and nucleon number 4. Describe the distribution of mass and charge within an atom 5. Describe the behavior of beams of protons, neutrons and electrons moving at the same velocity in an electric field 6. Determine the numbers of protons, neutrons and electrons present in both atoms and ions given atomic or proton number, mass or nucleon number and charge 7. Explain qualitatively the variations in atomic radius and ionic radius across a period and down a group 8. Define the term isotope in terms of numbers of protons and neutrons 9. Understand the notation for isotopes 10. State that and explain why isotopes of the same element have the same chemical properties and different physical properties, limited to mass and density 11. Understand the terms: shells, sub-shells and orbitals, principal quantum number (n), ground state, limited to electronic configuration 12. Describe the number of orbitals making up s, p and d sub-shells, and the number of electrons that can fill s, p and d sub-shells 13. Describe the order of increasing energy of the sub-shells within the first three shells and the 4s and 4p sub-shells 14. Describe the electronic configurations to include the number of electrons in each shell, sub-shell and orbital 15. Explain the electronic configurations in terms of energy of the electrons and inter-electron repulsion 16. Determine the electronic configuration of atoms and ions given the atomic or proton number and charge, using either of the following conventions 17. Understand and use the electrons in boxes notation 18. Describe and sketch the shapes of s and p orbitals 19. Describe a free radical as a species with one or more unpaired electrons 20. Understand the concept of ionization energy and its trends across a period and down a group of the Periodic Table and the variation in successive ionization energies of an element 21. Understand that ionization energies are due to the attraction between the nucleus and the outer electron 22. Explain the factors influencing the ionization energies of elements in terms of nuclear charge, atomic/ionic radius, shielding by inner shells and sub-shells and spin-pair repulsion 23. Deduce the electronic configurations of elements using successive ionization energy data 24. Deduce the position of an element in the Periodic Table using successive ionization energy data 25. Use mass spectrometer to determine the relative atomic mass of an element from its isotopic composition. 26. Perform calculations involving non-integer relative atomic masses and abundance of isotopes from given data, including mass spectra. 27. Understand the concept of emission spectra and use it to deduce the electronic configuration of elements. |
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Knowledge: Students will know… ● How an atom is structured and the subatomic particles it contains. ● Arrangement of electrons in the subshells and the electronic configurations of the elements. ● The quantum theory understanding of atomic orbitals and radius. Students will understand… ● Terms like quantization, isotopes, orbitals, and ionization. |
Skills: Students will be able to… ● Describe atoms as the fundamental particles of elements and their structures. ● Understand the phenomena of ionization and its relation with the atomic number and atomic size. ● Evaluate the forces involved at subatomic levels and estimate their relative magnitudes. ● Explain the stability of an atomic structure. ● Discuss the theory of atomic structure starting from Rutherford, continuing through Bohr and explaining the modern quantum theory.
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Perspectives ● Evolution of atomic theory: This perspective highlights the historical development of atomic theory, from ancient Greek philosopher Democritus' idea of atoms to John Dalton's law of definite proportions and atomic theory. For example, students can learn about how the discovery of electrons by J.J. Thomson, and the subsequent development of atomic models by Niels Bohr and Ernest Rutherford, led to a deeper understanding of the structure of atoms. ● Atom-molecule interaction: This perspective focuses on how the properties of atoms and molecules interact and affect the properties of materials. For example, students can learn about the effect of electron configuration on the reactivity of elements, and how the arrangement of atoms in a molecule affects its shape and reactivity. ● Modern applications: This perspective emphasizes the practical applications of atomic theory and its impact on fields such as medicine, energy, and technology. For example, students can learn about the role of atomic theory in the development of X-ray crystallography and its use in determining the structures of biological molecules, as well as the use of nuclear reactions in nuclear power plants and medical imaging. |
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Learning Activities
Creating a Trending Periodic Table
Objective: To understand the trends in the periodic table and their relation to the electron configuration of elements.
Materials: ● 10 elements with their atomic number, symbol, and electronegativity ● 10 blank periodic table sheets for each student or group ● Colored pens or markers
Procedure: ● Give each student or group a set of data for 10 elements, including their atomic number, symbol, and electronegativity. ● Instruct students to use the data to create their own periodic table, organizing the elements based on their electronegativity trend. ● Encourage students to use different colors or symbols to represent the trends and make their periodic table visually appealing. ● Once they have finished creating their periodic table, have them present their work to the class and discuss their reasoning behind their arrangements. ● As a class, compare the different periodic tables and discuss the similarities and differences in the arrangements. ● Facilitate a discussion on the trends in electronegativity and their relationship to the electron configuration of elements.
Assessment: ● Observe student participation and engagement during the presentation and discussion of their periodic tables. ● Evaluate their periodic table for accuracy and the use of color or symbols to represent the trends in electronegativity. ● Assess their understanding of the relationship between electronegativity and electron configuration through class discussions and questions.
Expected Results: Students will have a clear understanding of the trends in electronegativity in the periodic table. Students will have the ability to apply their understanding of electron configuration to explain the trends in electronegativity. Students will have engaged in higher-order thinking skills through the creation and presentation of their periodic table.
Spectroscopy Demonstration: Set up a spectroscopy demonstration in the classroom using a spectroscope or a laser pointer and a diffraction grating. Students can observe the emission spectra of different elements and compare the patterns to determine the elements' electronic configurations. The teacher can lead a discussion about how spectroscopy is used in real-world chemistry applications. In case a spectroscope is not available, spectroscopic data can be used. |
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Domain: Chemical Bonding
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Standard: Students should be able to: Explain the concept of chemical bonding and describe the different types of bonds, including ionic, covalent, and metallic bonds. Discuss the factors that affect bond strength, including bond length and bond energy. Describe the properties of molecular compounds and how they are affected by the type of bond they contain. Apply the principles of chemical bonding to explain the behavior of substances in different physical states. Describe the role of chemical bonding in chemical reactions, including the formation and breaking of bonds.
Benchmark I: Students can
describe the types of chemical bonds, including ionic, covalent, and metallic
bonds. |
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Student Learning Outcomes 1. Define electronegativity as the power of an atom to attract electrons to itself 2. Explain the factors influencing the electronegativities of the elements in terms of nuclear charge, atomic radius and shielding by inner shells and sub-shells 3. State and explain the trends in electronegativity across a period and down a group of the Periodic Table 4. Use the differences in Pauling electronegativity values to predict the formation of ionic and covalent bonds 5. Define ionic bonding as the electrostatic attraction between oppositely charged ions (positively charged cations and negatively charged anions) and describe ionic bonding including the examples of sodium chloride, magnesium oxide and calcium fluoride 6. Define metallic bonding as the electrostatic attraction between positive metal ions and delocalized electrons 7. Define covalent bonding as electrostatic attraction between the nuclei of two atoms and a shared pair of electrons, describe covalent bonding in molecules, use the concept of hybridization to describe sp, sp2 and sp3 orbitals and use bond energy values and the concept of bond length to compare the reactivity of covalent molecules 8. State and explain the shapes of, and bond angles in, molecules by using VSEPR theory, predict the shapes of, and bond angles in, molecules and ions analogous to those specified 9. Describe the types of van der Waals’ force: - instantaneous dipole – induced dipole (id-id) force, also called London dispersion forces - permanent dipole – permanent dipole (pd-pd) force, including hydrogen bonding - Hydrogen bonding as a special case of permanent dipole – permanent dipole force between molecules where hydrogen is bonded to a highly electronegative atom 10. Describe hydrogen bonding, limited to molecules containing N–H and O–H groups, including ammonia and water as simple examples 11. Use the concept of hydrogen bonding to explain the anomalous properties of H2O (ice and water) 12. Use the concept of electronegativity to explain bond polarity and dipole moments of molecules 13. Describe van der Waals’ forces as the intermolecular forces between molecular entities and explain the types of van der Waals’ force 14. State that, in general, ionic, covalent and metallic bonding are stronger than intermolecular forces 15. Use dot-and-cross and lewis dot diagrams to show the arrangement of electrons in covalent molecules and ions. |
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Knowledge: Students will know… ● The concept of chemical bonding and the various types of bonds atoms form. ● The relative strengths of atomic bonds and the forces involved in each of them. ● The concept of covalent bonds and the different theories that explain the shapes, strengths, and lengths of these bonds. ● The concept of Hydrogen Bonding and its involvement in maintaining the structure of molecules like water and ammonia. Students will understand… ● Terms like Electronegativity, Van der Waals’ forces, Dipoles, and Hybridization. |
Skills: Students will be able to… ● Explain the structure of different compounds formed as a result of chemical bonding and compare their relative strengths and characteristics. ● Explain the geometry of molecules and understand different shapes the atoms can arrange in based on the kind of bond involved. ● Compare the theories concerning the formation of covalent bonds and their postulates and predictions about the bond length and strength. ● Evaluate the involved intermolecular forces between molecules and their role in determining the physical and chemical properties of the compounds.
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Perspectives ● The development of chemical bonding theories: From early bonding theories like the ionic and covalent models to more recent developments like orbital hybridization and molecular orbitals, understanding the evolution of chemical bonding theories can provide a deeper appreciation for how our understanding of chemical bonds has changed over time. ● The role of chemical bonding in determining the properties of matter: Chemical bonding plays a key role in determining the properties of matter, such as melting and boiling points, reactivity, and solubility. Understanding how different bonding types can lead to different properties can help students understand why different materials behave in unique ways. ● The interplay between chemical bonding and the environment: Chemical bonding can play a role in environmental issues, such as air and water pollution, soil contamination, and climate change. Understanding the mechanisms behind chemical bonding reactions can help students appreciate the impact of these reactions on the environment and the potential for human actions to mitigate these effects. |
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Learning Activities
Trend in electronegativity across period 3
Materials: ● Sodium (Na), Magnesium (Mg), Aluminum (Al), Silicon (Si), Phosphorus (P), Sulfur (S), Chlorine (Cl), Argon (Ar) ● Beaker of distilled water ● Litmus paper ● Test tubes ● Pipettes
Procedure: ● Prepare 10 test tubes, one for each element in the list above. ● Label each test tube with the name of the element. ● Using a pipette, add 1 mL of distilled water to each test tube. ● Add a small piece of each element to each test tube, starting with Sodium and ending with Calcium. ● Observe the reaction of each element with water and record the results in a data table. ● Use the results to create a periodic table with the elements arranged in order of increasing electronegativity.
Data Table:
Element | Reaction with water | Electronegativity Na | Releases hydrogen gas, forms a basic solution | Lowest Mg | Releases hydrogen gas, forms a basic solution | Low Al | No reaction | Moderate Si | No reaction | Moderate P | Reacts to form a neutral solution | Moderate S | Reacts to form an acidic solution | High Cl | Reacts to form an acidic solution | Highest Ar | No reaction | N/A K | Releases hydrogen gas, forms a basic solution | Low Ca | No reaction | Moderate
Expected Results: ● Sodium and Potassium will react with water to release hydrogen gas, forming a basic solution. ● Magnesium will also release hydrogen gas, but to a lesser extent than Sodium and Potassium. ● Aluminum and Silicon will not react with water. ● Phosphorus will react with water to form a neutral solution. ● Sulfur will react with water to form an acidic solution. ● Chlorine will react with water to form an acidic solution, showing the highest electronegativity. ● Argon is an inert gas and will not react with water.
Conclusion: The trend in electronegativity of period 3 elements can be observed by their behavior in aqueous solutions. The electronegativity of the elements increases from Sodium to Chlorine, with Sodium having the lowest electronegativity and Chlorine having the highest. This activity demonstrates the relationship between electronegativity and the ability of an element to attract electrons from other atoms in a chemical bond.
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Domain: Environmental
Chemistry
Topic: Atmosphere
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Standard: Students should be able to: Describe the composition and structure of the Earth's atmosphere, including the major gases and trace gases. Explain the role of the atmosphere in the Earth's climate, including the greenhouse effect. Discuss the sources and effects of atmospheric pollutants, including greenhouse gases and air pollutants. Apply the principles of chemical reactions to explain the formation and removal of atmospheric pollutants. Describe the role of atmospheric chemistry in environmental chemistry and its impact on air quality and climate.
Benchmark I: Demonstrate an
understanding of the composition, structure and functions of the Earth's
atmosphere, including the role of atmospheric gases, pollutants and
greenhouse effect. |
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Student Learning Outcomes 1. Understanding of the properties and composition of air and the factors that affect air quality
2. Knowledge of the sources and effects of air pollution, including both natural and human-caused pollutants including Carbon monoxide (CO), Sulfur dioxide (SO2),Nitrogen oxides (NOx), Particulate matter (PM), Ozone (O3), Lead (Pb), Mercury (Hg), Polycyclic aromatic hydrocarbons (PAHs), Persistent organic pollutants (POPs), Greenhouse gases (such as carbon dioxide, methane, and nitrous oxide), Chlorofluorocarbons (CFCs) and other ozone-depleting substances, Volatile organic compounds (VOCs), Heavy metals (such as lead, mercury, and cadmium))
3. Familiarity with the methods and techniques used to measure and monitor air quality
4. Understanding of the impact of human activities on the atmosphere, including the effects of burning fossil fuels and deforestation
5. Knowledge of the chemical reactions and processes that occur in the atmosphere, such as the formation of smog and acid rain
6. Familiarity with the laws and regulations related to air quality and the measures used to control air pollution
7. Ability to analyze data and interpret air quality measurements and trends
8. Understanding of the link between air quality and human health and the ability to evaluate the potential health risks associated with air pollution
9. Knowledge of the technologies and strategies used to reduce air pollution and improve air quality, such as emissions control and renewable energy sources.
10. Ability to design experiments and collect data to test hypotheses about air quality 11. Familiarity with the global scale problems of air pollution, such as global warming and the greenhouse effect. 12. Ability to think critically about the economic, social and political issues related to air pollution and air quality management. 13. Familiarity with light pollution, microplastics, noise pollution, toxic waste and plastic pollution. |
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Knowledge: Students will know… ● Composition of air and the leading sources of air pollutants in the atmosphere. ● The sources of these pollutants and their effects on human and atmospheric health. ● Chemical reactions between the pollutants and the atmospheric gases to produce smog and acid rain. ● Economic and environmental issues underlying changing air quality. |
Skills: Students will be able to… ● Make suggestions about fighting climate change. ● Discuss the main sources of air pollution and make recommendations for fixing them. ● Explain the harmful effects of smog and acid rain and present precautionary measures to avoid these effects. ● Provide suggestions on making energy sources more renewable.
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Perspectives ● Understanding the composition and structure of the Earth's atmosphere: Discuss how the composition of the Earth's atmosphere changes with altitude, including the presence of trace gases such as ozone and carbon dioxide. In the context of Pakistan, mention the impact of increasing industrialization and urbanization on air quality, specifically in cities such as Karachi and Lahore. ● Exploring the role of the atmosphere in the Earth's climate: Discuss how the atmosphere plays a crucial role in regulating the Earth's temperature through the greenhouse effect. Mention the impact of climate change on the monsoon patterns in Pakistan, and its effects on agriculture and water availability. ● Examining the sources and effects of atmospheric pollutants: Discuss the sources of air pollutants, including industrial emissions, vehicular emissions, and natural sources. In the context of Pakistan, mention the air pollution crisis in cities like Lahore, which is caused by the high levels of vehicular and industrial emissions. ● Applying the principles of chemical reactions to explain the formation and removal of atmospheric pollutants: Discuss the chemical reactions that lead to the formation of air pollutants, such as the reaction of nitrogen oxides and volatile organic compounds to form ground-level ozone. Mention the efforts being made to combat air pollution, such as the installation of scrubbers in power plants and the promotion of alternative modes of transportation. |
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Learning Activities
Measuring the Amount of Oxygen in the Air
Objective: To measure the amount of oxygen in the air using common household materials.
Materials:
Small, clear plastic bottle with a lid Water Alka-Seltzer/Aspirin tablet Scale Ruler
Procedure: Fill the bottle with water, leaving about 1 inch of air space at the top. Measure the initial volume of air in the bottle using the ruler. Record the volume in milliliters. Crush an Alka-Seltzer/Aspirin tablet into a fine powder and add it to the water in the bottle. Quickly screw the lid on the bottle, making sure it is tightly sealed. Observe the reaction of the Alka-Seltzer with the water, which will produce carbon dioxide gas. The carbon dioxide gas will displace the air in the bottle, increasing the volume of the bottle. Measure the final volume of the bottle using the ruler. Record the volume in milliliters. Calculate the volume of air displaced by subtracting the initial volume from the final volume. The volume of air displaced is directly proportional to the amount of oxygen in the air. You can use the following conversion factor to determine the percentage of oxygen in the air: (Volume of air displaced / Total volume of the bottle) * 100 = % oxygen in the air.
Precautions: Make sure to crush the Alka-Seltzer tablet into a fine powder before adding it to the water to maximize the amount of carbon dioxide produced. Make sure to screw the lid on the bottle tightly to prevent the carbon dioxide from escaping. The reaction between Alka-Seltzer and water can get quite vigorous, so be careful not to spill any of the solution while measuring the final volume of the bottle.
References: Chem1.com. (n.d.). Alka-Seltzer and the Ideal Gas Law. [online] Available at: https://www.chem1.com/acad/sci/aboutgaslaws.html [Accessed 9 Feb 2023]. Science Bob. (n.d.). How much Oxygen is in the Air? [online] Available at: https://www.sciencebob.com/how-much-oxygen-is-in-the-air/ [Accessed 9 Feb 2023].
Investigating Air Pollution with Bumper Stickers
Objective: To study the effects of air pollution on the environment and understand the role of nitrogen oxides and sulfur dioxide in the formation of acid rain.
Materials:
Bumper stickers or adhesive labels Markers Plastic bags Ruler or measuring tape
Procedure: Cut out a bumper sticker or adhesive label and place it inside a plastic bag. Seal the bag. Label the bag with the date and time it was collected. Place the bag in an area with high air pollution, such as near a busy road or industrial area. Leave it there for 24 hours. Remove the bag and examine the bumper sticker. Observe any discoloration or changes in color. Repeat steps 1 to 4 in a clean air area, such as a park or a countryside. Compare the bumper stickers from the two different locations and discuss the differences in discoloration or color changes. Measure the size of any discolored areas on both stickers and compare the results.
Analysis: The bumper stickers will change color due to the presence of nitrogen oxides and sulfur dioxide in the air. The discoloration will be more pronounced in the bumper sticker from the area with high air pollution. The discoloration of the bumper sticker is a result of acid rain formation caused by the nitrogen oxides and sulfur dioxide in the air.
Conclusion: This activity helps students understand the effects of air pollution on the environment and the role of nitrogen oxides and sulfur dioxide in the formation of acid rain. Students will appreciate the importance of reducing air pollution to protect our environment.
References: United States Environmental Protection Agency (EPA). (2021). Air Pollution and Your Health. Retrieved from https://www.epa.gov/air-pollution-and-your-health United States Environmental Protection Agency (EPA). (2021). What is Acid Rain? Retrieved from https://www.epa.gov/acidrain/what-acid-rain National Center for Biotechnology Information (NCBI). (2021). Air Pollution: Types, Sources, Effects and Control. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6936902/ |
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