Stoichiometry Test Review

General Stoichiometry

Mole to Mole Problems

Converting Mass to Mass

Limiting Reagents

Percent Yield

100

What is stoichiometry?

the mathematical calculation of relative products and reactants in a balanced chemical equation

100

What is the term for the ratio between the coefficients of any two reactants or products in a balanced chemical equation?

mole ratio

100

A manufacturer of bicycles has 50 wheels, 30 frames, and 24 seats. How many bicycles can be manufactured using these parts?

24 bicycles

100

In the reaction between CO and Fe304 the theoretical yield in an experiment is calculated to be 47.2 g Fe. When a careless chemistry student carries out the experiment, the actual yield is 42.9 g Fe. Calculate the percentage yield.

90.9%

100

What is percent yield?

a comparison, expressed as a percentage, of how much product is made compared to the maximum that theoretically could have been made

200

What do the coefficients in a balanced equation tell us?

the number of moles present for each substance

200

How can you tell when something is going to be a mole ratio problem?

When there is only one number given (in moles), and the other number the question is asking for is also in moles

200

The fizz produced when an Alka-Seltzer tablet is dissolved in water is due to the reaction between sodium bicarbonate, NaHCO3, and citric acid, H3C6H5O7: 3 NaHCO3 (aq) + H3C6H5O7 (aq) → 3 CO2 (g) + 3 H2O(l) + Na3C6H5O7 (aq) In a certain experiment 1.00 g of sodium bicarbonate and 1.00 g of citric acid are allowed to react. Which reactant is the limiting reactant?

NaHCO3

200

After you have completed your two equations when doing a limiting reagent problem, how can you tell which is the limiting reagent?

the reactant that produces the smallest amount of product

200

What is the formula for percent yield?

actual yield/theoretical yield x 100

300

Stoichiometry must always start with a ________________ chemical equation.

balanced

300

If 3 moles Al2O3 decompose, how many moles of oxygen are produced? 2Al2O3 -> 4Al + 3O2

4.5 moles O2

300

0.523 g

300

What is a limiting reactant? (What does it do?)

A limiting reactant in a chemical reaction is the substance that -Is used up first -Stops the reaction -Limits the amount of product that can form

300

Some cars can use butane (C4H10) as fuel: 2 C4H10 + 13 O2 --> 8 CO2 + 10 H2O How many grams of CO2 are produced from the combustion of 100. grams of butane?

303 grams

400

What is the difference between molecules and formula units?

molecules is a term used for covalent compounds and formula units is a term used for ionic compounds

400

If 3.6 moles of C2H2 are burned, how many moles of CO2 are produced? 2C2H2 + 5O2 --> 4CO2 + 2H2O

7.2 moles CO2

400

6.50 grams of aluminum reacts with an excess of oxygen. How many grams of aluminum oxide are formed? 4Al + 3O2 --> 2Al2O3

12.3 g Al2O3

400

How can you tell if a problem is a limiting reagent problem (other than it specifically saying so)?

You will have two givens that are the amounts of two reactants in grams

400

The fermentation of glucose, C6H12O6, produces ethyl alcohol, C2H5OH, and CO2 as shown here: C6H12O6 (aq) → 2 C2H5OH(aq) + 2 CO2 (g). How many grams of C6H12O6 are needed to form 2.00 g of C2H5OH?

3.91 g

500

What are two things that are always conserved in a chemical reaction?

mass, matter (atoms)

500

MAKING BISQUICK™PANCAKES 2 cups Bisquick 1 cup milk 2 eggs makes 14 pancakes

If you have 10 cups of Bisquick™, 10 cups of milk, and 12 eggs, how many pancakes can you make?

70 pancakes

500

If 10.1 g of Fe are added to a solution of Copper (II) Sulfate, how many grams of solid copper would form? 2Fe + 3CuSO4 --> Fe2(SO4)3 + 3Cu

17.2g Cu

500

50g of Al are added to 100g HCl, how many grams of H2 are produced? 2Al + 6HCl --> 2AlCl3 + 3H2

2.74g H2

500

21g of CaCO3 produce 7.2g of CaO, what is the % yield? CaCO3 --> CaO + CO2

61.2%