R2.1 How much? The Amount of Chemical Change

PART 1: No Solutions and Gases

How are chemical equations used to calculate reacting ratios?

R2.1 How much? The amount of chemical change.pptx

Understand how to accurately measure the following to an appropriate level of precision: Mass, Volume
Drying to constant mass
Controlling Variables: calibrate measuring apparatus (calorimeter)
Controlling Variables: maintain constant environmental conditions of systems
Use basic arithmetic and algebraic calculations to solve problems.
Carry out calculations involving decimals, fractions, percentages, ratios, reciprocals and exponents.

Chemical equations show the ratio of reactants and products in a reaction.
The mole ratio of an equation can be used to determine the masses of reactants and products
The limiting reactant determines the theoretical yield.
The percentage yield is calculated from the ratio of experimental yield to theoretical yield.

Reactivity 3.2—When is it useful to use half equations?
Tool 1, Inquiry 1, 2, 3—What errors may cause the experimental yield to be i) higher and ii) lower than the theoretical yield?
Structure 2.4, Reactivity 2.2—The atom economy and the percentage yield both give important information about the “efficiency” of a chemical process. What other factors should be considered in this assessment?

PART 2: Solutions and Gases

S1.4.5; R2.1 Solutions.pptx

R2.1.1—Chemical equations show the ratio of reactants and products in a reaction.
- Deduce chemical equations when reactants and products are specified.
R2.1.2—The mole ratio of an equation can be used to determine:
- the masses and/or volumes of reactants and products
- the concentrations of reactants and products for reactions occurring in solution.
- Calculate reacting masses and/or volumes and concentrations of reactants and products.
R2.1.3—The limiting reactant determines the theoretical yield.
- Identify the limiting and excess reactants from given data.
R2.1.4—The percentage yield is calculated from the ratio of experimental yield to theoretical yield.
- Solve problems involving reacting quantities, limiting and excess reactants, theoretical, experimental and percentage yields.
R2.1.5—The atom economy is a measure of efficiency in green chemistry.
- Calculate the atom economy from the stoichiometry of a reaction.

Reactivity 3.2—When is it useful to use half equations?
Tool 1, Inquiry 1, 2, 3—What errors may cause the experimental yield to be i) higher and ii) lower than the theoretical yield?
Structure 2.4, Reactivity 2.2—The atom economy and the percentage yield both give important information about the “efficiency” of a chemical process. What other factors should be considered in this assessment?