BMST - Basic Math and Science Chemical Reactions and Stoichiometry Questions and Answers

Question 1

When the following chemical equation is balanced, what is the correct coefficient for sodium hydroxide (NaOH)?  ___ FeCl₃ + ___ NaOH → ___ Fe(OH)₃ + ___ NaCl

Accepted Answer

3

Answer

2

Answer

6

Answer

1

Question 2

A chemist observes a reaction where a single, complex compound breaks down into two or more simpler substances when heat is applied. Which of the following reaction types does this observation describe?

Accepted Answer

Decomposition

Answer

Synthesis

Answer

Single Replacement

Answer

Double Replacement

Question 3

What is the approximate molar mass of magnesium nitrate, Mg(NO₃)₂?

Accepted Answer

148.3 g/mol

Answer

74.3 g/mol

Answer

124.3 g/mol

Answer

86.3 g/mol

Question 4

In the complete combustion of propane (C₃H₈), the balanced equation is: C₃H₈ + 5O₂ → 3CO₂ + 4H₂O. If 44.1 g of propane is burned, how many grams of carbon dioxide (CO₂) are produced?

Accepted Answer

132.3 g

Answer

44.1 g

Answer

88.2 g

Answer

176.4 g

Question 5

A technician is performing a reaction that requires 1 mole of reactant X for every 2 moles of reactant Y. The technician mixes 3 moles of X with 5 moles of Y. Which of the following statements is true?

Accepted Answer

Reactant Y is the limiting reactant, and some X will be left over.

Answer

Reactant X is the limiting reactant, and some Y will be left over.

Answer

Both reactants will be completely consumed.

Answer

The reaction will not proceed as there is no limiting reactant.

Question 6

In an experiment, the calculated maximum amount of product that could be formed (theoretical yield) was 50.0 grams. After the reaction, the actual amount of product collected was 42.5 grams. What is the percent yield of this reaction?

Accepted Answer

85.0%

Answer

117.6%

Answer

92.5%

Answer

7.5%