Chapter 12 - Stoichiometry

Question 0

Stoichiometry

Answer 0

The calculation of quantities in chemical reactions.

Question 1

How do chemists use balanced chemical equations?

Answer 1

Chemists use balanced chemical equations as a basis to calculate how much reactant is needed to how much products will be formed in a reaction.

Question 2

It terms of what quantities can you interpret a balanced chemical equation?

Answer 2

A balanced chemical equation can be interpreted in terms of different quantities, including numbers of atoms, molecules or moles, mass and volume.

Question 3

Mole ratio

Answer 3

Is a conversion factor derived from the coefficients of a balanced chemical equation interpreted in terms of moles.

Question 4

How are mole ratios used in chemical calculations?

Answer 4

In chemical calculations, mole ratios are used to convert between a given number of moles of a reactant or product to moles of a different reactant or product.

Question 5

What is the general procedure for solving a Stoichiometric problem?

Answer 5

In a typical Stoichiometric problem, the give quantity is first converted to moles. Then the mole ratio from the balanced equation is used to calculate the number if moles of the wanted substance. Finally, the moles are converted to any other unit of measurement related to the unit mole, as the problem requires.

Question 6

How is the amount of product in a reaction affected by an insufficient quantity of any of the reactants?

Answer 6

In a chemical reaction, an insufficient quantity of any of the reactants will limit the amount of product that forms.

Question 7

Limiting reagent

Answer 7

The reactant that determines the amount of product that can be formed by a reaction.

Question 8

Excess reagent

Answer 8

The reactant that is not completely used up in a reaction.

Question 9

Theoretical yield

Answer 9

Is the maximum amount of product that could be formed from given amounts of reactants.

Question 10

Actual yield

Answer 10

The amount of product that actually forms when the reaction is carried out in the laboratory.

Question 11

Percent yield

Answer 11

The ratio of the actual yield to the theoretical yield expressed as a percent.

Question 12

What does a percent yield of a reaction measure?

Answer 12

The percent yield is a measure of the efficiency of a reaction carried out in the laboratory.