Chem T2, U6 Mole and Chemical Composition
Chemistry: Term 2, Unit 6 Topic: Mole and Chemical Composition Duration: Traditional (50 minute periods) : 10-14 (adjust to student needs using professional discretion) Block Schedule (90 minute periods) : 5-7 (adjust to student needs using professional discretion)
Eligible Content This is what the State of Pennsylvania wants your students to know and be able to do by the end of the unit. CHEM.B.1.1.1 Apply the mole concept to representative particles (e.g., counting, determining mass of atoms, ions, molecules, and/or formula units). CHEM.B.1.2.1 Determine the empirical and molecular formulas of compounds. CHEM.B.1.2.2 Apply the law of definite proportions to the classification of elements and compounds as pure substances. CHEM.B.1.2.3 Relate the percent composition and mass of each element present in a compound.
Performance Objectives These are examples, created by SDP teachers, of how you may translate the eligible content into learning goals for your classroom. SWBAT use the concept of the mole IOT determine the number of particles present. SWBAT use an element’s atomic weight (from the periodic table) IOT determine the relationship of moles to a mass. SWBAT calculate molar mass of given molecule or compound IOT determine the number of moles in a sample. SWBAT use percentage composition information IOT calculate the empirical formula SWBAT use an empirical formula IOT calculate the molecular formula SWBAT use percent information IOT calculate the weighted average atomic mass.
Key Terms and Definitions
23 avogadro’s number: 6.022 × 10 , the number of atoms or molecules in 1 mol empirical formula: a chemical formula that shows the composition of a compound in terms of the relative numbers and kinds of atoms in the simplest ratio excess reactant: the substance that is not used up completely in a reaction limiting reactant: the substance that controls the quantity of product that can form in a chemical reaction molar mass: the mass in grams of 1 mol of a substance mole: the SI base unit used to measure the amount of a substance whose number of particles is the same as the number of atoms of carbon in exactly 12 g of carbon-12 molecular formula: a chemical formula that shows the number and kinds of atoms in a molecule, but not the arrangement of the atoms Isotope: atoms of the same element type having different number of protons. Average atomic mass: the percentage weight average atomic mass of the different isotope. percent composition: the percentage by mass of each element in a compound
Starting Points An overview of how the content and skills of this unit connect to students' prior knowledge.
So far students have learned many of the fundamental chemical concepts. These topics include conversions and dimensional analysis, valence electron theory, the mole and Avogadro’s number, and simple naming of ionic and covalent compounds. Now the students will bring together these concepts to understand how and why compounds can form. Specifically, they will bring the mole concept into formula writing in order to determine empirical and molecular formulas as well as percent composition. Chem T2, U6 Mole and Chemical Composition
In order to accurately predict quantities of products, students will learn: -molar mass -percent composition -empirical formulas and molecular formulas -mole ratios -conversions between moles, mass, volume, and number of particles -Factor Label Method -Law of Definite Proportions -Law of Multiple Proportions -Law of Conservation of Mass -Law of Conservation of Energy All four Laws come from Chapter 3. However, due to their importance, at least the first two should be reinforced here, too.
Resources by Performance Objective 1. SWBAT use the concept of the mole IOT determine the number of particles present. a. Holt pp. 224-9 b. Literacy links i. Molar Masses & Conversions ii. Khan Academy: Molecular Composition (select appropriate subsection) c. CK12 Link: How big is Avogadro’s number d. Philadelphia Core Curriculum Resources (Spiral Bound green book): i. The Mole Concept & Avogadro’s Number (pp. 150-1) ii. The volume of a mole of gas mini-lab, Molar Mass, (pp.156-7)
2. SWBAT use an element’s atomic weight (from the periodic table) IOT determine the relationship of moles to a mass. a. Holt pp. 230-3 b. Literacy links i. Molar Masses & Conversions ii. Khan Academy: Molecular Composition (select appropriate subsection) c. Philadelphia Core Curriculum Resources (Spiral Bound green book): i. Calculating the Number of Molecules in a Substance (pp. 152-3) ii. Molar Mass & Gram Atomic Mass (pp. 154-5) iii. The volume of a mole of gas mini-lab, Molar Mass, (pp.156-7)
3. SWBAT use percent information IOT calculate the weighted average atomic mass. a. Holt pp. 234-6
4. SWBAT calculate molar mass of given molecule or compound IOT determine the number of moles in a sample. a. Holt pp. 236-240 b. Literacy links: Khan Academy: Molecular Composition (select appropriate subsection) c. Philadelphia Core Curriculum Resources (Spiral Bound green book): i. Calculating the Number of Molecules in a Substance (pp. 152-3)
5. SWBAT use percentage composition information IOT calculate the empirical formula a. Holt pp. 241-3 b. Literacy links: Khan Academy: Molecular Composition (select appropriate subsection) c. Philadelphia Core Curriculum Resources (Spiral Bound green book): i. Percent mass, empirical formula, and molecular formulas (pp. 158-161) Chem T2, U6 Mole and Chemical Composition
6. SWBAT use an empirical formula IOT calculate the molecular formula a. Holt pp. 245-8 b. Literacy links: Khan Academy: Molecular Composition (select appropriate subsection) c. Philadelphia Core Curriculum Resources (Spiral Bound green book): i. Percent mass, empirical formula, and molecular formulas (pp. 158-161) d. Lab: Percent Composition
Sample Questions from PDESAS Assessment Creator, Diagnostic Section: Chemistry
Given the balanced equation representing a reaction:
+ – H ( aq) + OH ( aq) → H2O + energy In this reaction there is conservation of (1)mass, only (2)mass and charge, only (3)charge and energy, only (4)charge, energy, and mass
Given the balanced equation representing a reaction:
2H2 + O2 → 2H2O
What is the total mass of water formed when 8 grams of hydrogen reacts completely with 64 grams of oxygen?
(1)18 g (2)36 g (3)56 g (4)72 g
Given the balanced equation representing a reaction:
C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(g)
What is the total number of moles of O2(g) required for the complete combustion of 1.5 moles of C3H8(g)? (1)0.30 mol (2)1.5 mol (3)4.5 mol Chem T2, U6 Mole and Chemical Composition (4)7.5 mo
Resources
Textbook References 1. Ch.7 The Mole and Chemical Composition, pp. 223 - 257
Literacy links: ● Khan Academy: Molecular Composition including sections for: ○ empirical, molecular, and structural formulas ○ Molecular mass composition ○ Molecular weight percentages ○ Empirical formula from mass composition ● Molar Masses & Conversions
CK12 ● How big is Avogadro’s number ● Exam Ch 7, 4 versions ● Lab: Percent Composition
Philadelphia Core Curriculum Resources (Spiral Bound green book) Unit 6: pp. 150-172 ● The Mole Concept & Avogadro’s Number (pp. 150-1) ● Calculating the Number of Molecules in a Substance (pp. 152-3) ● Molar Mass & Gram Atomic Mass (pp. 154-5) ● The volume of a mole of gas mini-lab, Molar Mass, (pp.156-7) ● Percent mass, empirical formula, and molecular formulas (pp. 158-161)
PA Standards with linked Materials and Resources from PDESAS ● 3.2.C.A2 Chemistry of Petroleum 4: Treatment of Hydrocarbons ● 3.2.10.A5. The particle adventure
Essential Questions How does the mole concept allow us to count particles? How are moles represented in a chemical formula? Extension: If you were the owner of a chemical company, how would you use the mole concept to efficiently manufacture the desired amount of a chemical with the least amount of waste?
PA Standards These are the PA Standards that underlie the Eligible Content in this unit.
3.2.C.A2 Use the mole concept to determine number of particles and molar mass for elements and compounds. Determine percent composition, empirical formulas, and molecular formulas. 3.2.10.A4 Predict the amounts of products and reactants in a chemical reaction using mole relationships. 3.2.C.A4 Interpret and apply the laws of conservation of mass, constant composition (definite proportions), and multiple proportions. 3.2.10.A5. SCALE Apply the mole concept to determine number of particles and molar mass for elements and compounds.
Common Core Standards for Science and Technical Subjects These are Common Core Standards that are related to the Eligible Content in this unit.
Chem T2, U6 Mole and Chemical Composition CC.3.5.11-12.A: Cite specific textual evidence to support analysis of science and technical texts, attending to important distinctions the author makes and to any gaps or inconsistencies in the account. CC.3.5.11-12.B: Determine the central ideas or conclusions of a text; summarize complex concepts, processes, or information presented in a text by paraphrasing them in simpler but still accurate terms. CC.3.5.11-12.C: Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks; analyze the specific results based on explanations in the tex Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant to grades 11–12 texts and topics. CC.3.5.11-12.G: Integrate and evaluate multiple sources of information presented in diverse formats and media (e.g., quantitative data, video, multimedia) in order to address a question or solve a problem. CC.3.5.11-12.H: Evaluate the hypotheses, data, analysis, and conclusions in a science or technical text, verifying the data when possible and corroborating or challenging conclusions with other sources of information. CC.3.5.11-12.I: Synthesize information from a range of sources (e.g., texts, experiments, simulations) into a coherent understanding of a process, phenomenon, or concept, resolving conflicting information when possible. CC.3.6.11-12.F: Conduct short as well as more sustained research projects to answer a question (including a self-generated question) or solve a problem; narrow or broaden the inquiry when appropriate; synthesize multiple sources on the subject, demonstrating understanding of the subject under investigation. CC.3.6.11-12.H: Draw evidence from informational texts to support analysis, reflection, and research.
Next Generation Science Standards
HS-PS-1-7 Use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction. [Clarification Statement: Emphasis is on using mathematical ideas to communicate the proportional relationships between masses of atoms in the reactants and the products, and the translation of these relationships to the macroscopic scale using the mole as the conversion from the atomic to the macroscopic scale. Emphasis is on assessing students’ use of mathematical thinking and not on memorization and rote application of problem-solving techniques.] [Assessment Boundary: Assessment does not include complex chemical reactions.]