BMST Chemical Reactions and Stoichiometry 4

Question 1

In stoichiometry, a mole ratio is obtained from:

Accepted Answer

The coefficients of a balanced chemical equation

Answer

Mole ratios come directly from the coefficients in a balanced equation and are used to convert between moles of different substances.

Question 2

Which symbol in a chemical equation indicates that a gas is produced?

Accepted Answer

(g) or ↑

Answer

The symbol (g) or an upward arrow (↑) indicates a gaseous product is released from the reaction.

Question 3

For the reaction N₂ + 3H₂ → 2NH₃, if 6 moles of H₂ are used, how many moles of NH₃ are produced?

Accepted Answer

4 moles

Answer

The ratio of H₂ to NH₃ is 3:2, so 6 moles H₂ × (2 mol NH₃ / 3 mol H₂) = 4 moles NH₃.

Question 4

What does a catalyst do in a chemical reaction?

Accepted Answer

Speeds up the reaction without being consumed

Answer

A catalyst lowers activation energy and speeds up a reaction but is not consumed and does not change the products.

Question 5

Which of the following correctly represents a precipitation reaction?

Accepted Answer

AgNO₃ + NaCl → AgCl↓ + NaNO₃

Answer

When AgNO₃ and NaCl solutions are mixed, AgCl forms as an insoluble precipitate (↓) that settles out.

BMST - Basic Math and Science Test Practice Test