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

What does a catalyst do in a chemical reaction?

Answer: Lowers the activation energy without being consumed

A catalyst lowers the activation energy of a reaction and is not consumed in the process.

In the equation N₂ + 3H₂ → 2NH₃, what is the mole ratio of H₂ to NH₃?

Answer: 3:2

The coefficients show 3 moles of H₂ produce 2 moles of NH₃, giving a ratio of 3:2.

Which term describes the minimum amount of reactant needed to produce a specific amount of product?

Answer: Limiting reagent

The limiting reagent is the reactant that is completely consumed first and determines the maximum amount of product.

The reaction CaCO₃ → CaO + CO₂ is best classified as which type?

Answer: Decomposition

One compound breaking into two simpler substances is the definition of a decomposition reaction.

What is the percent yield if the theoretical yield is 50 g and the actual yield is 40 g?

Answer: 80%

Percent yield = (actual yield / theoretical yield) × 100 = (40/50) × 100 = 80%.

In a neutralization reaction between an acid and a base, what are the two products typically formed?

Answer: Water and a salt

Acid-base neutralization produces a salt and water (e.g., HCl + NaOH → NaCl + H₂O).

How many molecules are in 1 mole of any substance?

Answer: 6.02 × 10²³

Avogadro's number states that 1 mole of any substance contains 6.02 × 10²³ particles.