## Unit Stoichiometry Mass Mass Calculations Worksheet 2 Answers

In this article, we will provide the answers to the Unit Stoichiometry Mass Mass Calculations Worksheet 2. This worksheet is designed to help students practice their skills in calculating the mass of reactants and products in chemical reactions. By providing the answers here, students can check their work and gain a better understanding of the concepts involved in stoichiometry.

### Question 1:

Calculate the mass of oxygen (O2) required to react completely with 25 grams of iron (Fe) according to the following balanced chemical equation:

4Fe + 3O2 → 2Fe2O3

**Answer: ** The molar mass of O2 is 32 g/mol. Using the ratio of the coefficients in the balanced equation, we can calculate the mass of O2 required:

25 g Fe * (3 mol O2 / 4 mol Fe) * (32 g O2 / 1 mol O2) = 60 g O2

Therefore, 60 grams of oxygen are required to react completely with 25 grams of iron.

### Question 2:

What mass of hydrogen gas (H2) is needed to produce 100 grams of water (H2O) according to the following balanced chemical equation:

2H2 + O2 → 2H2O

**Answer: **The molar mass of H2 is 2 g/mol. By using the stoichiometry of the balanced equation, we can calculate the mass of H2 required:

100 g H2O * (2 mol H2 / 2 mol H2O) * (2 g H2 / 1 mol H2) = 100 g H2

Therefore, 100 grams of hydrogen gas are needed to produce 100 grams of water.

### Question 3:

Determine the mass of iron(III) oxide (Fe2O3) that can be produced from 50 grams of iron (Fe) in the following balanced chemical equation:

4Fe + 3O2 → 2Fe2O3

**Answer: **The molar mass of Fe2O3 is 160 g/mol. By using the stoichiometry of the balanced equation, we can calculate the mass of Fe2O3 produced:

50 g Fe * (2 mol Fe2O3 / 4 mol Fe) * (160 g Fe2O3 / 1 mol Fe2O3) = 100 g Fe2O3

Therefore, 100 grams of iron(III) oxide can be produced from 50 grams of iron.

### Question 4:

What mass of chlorine gas (Cl2) is required to react with 200 grams of sodium (Na) in the following balanced chemical equation:

2Na + Cl2 → 2NaCl

**Answer: **The molar mass of Cl2 is 71 g/mol. Using the stoichiometry of the balanced equation, we can calculate the mass of Cl2 required:

200 g Na * (1 mol Cl2 / 2 mol Na) * (71 g Cl2 / 1 mol Cl2) = 71 g Cl2

Therefore, 71 grams of chlorine gas are needed to react with 200 grams of sodium.

### Question 5:

Calculate the mass of carbon dioxide (CO2) produced from the combustion of 50 grams of propane (C3H8) in the following balanced chemical equation:

C3H8 + 5O2 → 3CO2 + 4H2O

**Answer: **The molar mass of CO2 is 44 g/mol. By using the stoichiometry of the balanced equation, we can calculate the mass of CO2 produced:

50 g C3H8 * (3 mol CO2 / 1 mol C3H8) * (44 g CO2 / 1 mol CO2) = 660 g CO2

Therefore, 660 grams of carbon dioxide are produced from the combustion of 50 grams of propane.

By practicing these Unit Stoichiometry Mass Mass Calculations, students can enhance their understanding of stoichiometry and improve their problem-solving skills in chemistry.