RPAL Limiting Reagents 2

Question 1

For the reaction 2Al + 3Cl₂ → 2AlCl₃, if 0.6 mol Al and 0.6 mol Cl₂ are used, which is the limiting reagent?

Accepted Answer

Cl₂

Answer

Al

Answer

AlCl₃

Answer

Both are limiting

Question 2

A student mixes 5 g of H₂ and 32 g of O₂ for the reaction 2H₂ + O₂ → 2H₂O. What is the limiting reagent?

Accepted Answer

O₂

Answer

H₂

Answer

H₂O

Answer

Neither

Question 3

Which of the following is NOT a step in identifying the limiting reagent?

Accepted Answer

Calculating the percent yield of the reaction

Answer

Converting mass to moles for each reactant

Answer

Dividing moles by stoichiometric coefficients

Answer

Comparing the resulting ratios

Question 4

If a reaction uses 10 mol of each reactant and the stoichiometric ratio is 1:1, what is true about the limiting reagent?

Accepted Answer

There is no limiting reagent — both are consumed completely

Answer

The first reactant listed is limiting

Answer

The second reactant listed is limiting

Answer

The product determines which is limiting

Question 5

In a reaction with a 1:2 stoichiometric ratio (A:B), you have 3 mol A and 5 mol B. Which is limiting?

Accepted Answer

B

Answer

A

Answer

Neither

Answer

Both equally

Question 6

What quantity can be calculated directly from the moles of the limiting reagent?

Accepted Answer

Moles of product formed

Answer

Moles of excess reagent remaining

Answer

Activation energy of the reaction

Answer

Enthalpy change of the reaction