Question

Compound A and compound B react according to the following chemical equation: in which of the following cases will compound A be the limiting reagent? A + 2B-> 2C+D* O 0.5 mol A is combined with 0.3 mol B O 0.5 mol A is combined with 0.6 mol B O 0.2 mol A is combined with 0.3 mol B O 0.3 mol A is combined with 0.8 mol B

Answer 1

Compound A is the limiting reagent when 0.5 mol A is combined with 0.3 mol B, when 0.2 mol A is combined with 0.3 mol B, and when 0.3 mol A is combined with 0.8 mol B, as determined by stoichiometric coefficients in the reaction equation.

Step-by-step explanation:

When determining the limiting reagent in a chemical reaction, you compare the mole ratio of the reactants to the stoichiometry of the balanced chemical equation. In the reaction A + 2B → 2C + D, compound A will be the limiting reagent if there are fewer moles of A available compared to twice the moles of B, based on the stoichiometric coefficients.

To find the limiting reagent, you divide the number of moles of each reactant by its stoichiometric coefficient from the balanced equation. For compound A, this ratio is moles of A / 1, and for compound B, it is moles of B / 2. The reactant with the smaller ratio is the limiting reagent.

• 0.5 mol A is combined with 0.3 mol B: A is limiting because 0.5/1 < (0.3/2) × 2.
• 0.5 mol A is combined with 0.6 mol B: B is limiting because 0.5/1 > (0.6/2) × 2.
• 0.2 mol A is combined with 0.3 mol B: A is limiting because 0.2/1 < (0.3/2) × 2.
• 0.3 mol A is combined with 0.8 mol B: A is limiting because 0.3/1 < (0.8/2) × 2.

Therefore, compound A is the limiting reagent when 0.5 mol A is combined with 0.3 mol B and when 0.2 mol A is combined with 0.3 mol B, and also when 0.3 mol A is combined with 0.8 mol B.

Answer 2

0.3 mol A is combined with 0.8 mol B.

Step-by-step explanation:

Limiting reagent in a chemical reaction is defined as the reagent that is totally consumed when the chemical reaction is complete.

In the reaction:

A + 2B → 2C+D

For a reaction of 1 mole of A, you need two moles of B. That means for any quantity of A you need twice this quantity in B.

Thus, A is limiting reagent when moles of B are higher than twice moles of A.

* 0.5 mol A is combined with 0.3 mol B. Twice moles of A are 1.0 moles that are higher than 0.3 moles. A is not limitng reagent.

* 0.5 mol A is combined with 0.6 mol B. Twice moles of A are 1.0 moles that are higher than 0.6 moles. A is not limitng reagent.

* 0.2 mol A is combined with 0.3 mol B. Twice moles of A are 0.4 moles that are higher than 0.3 moles. A is not limitng reagent.

* 0.3 mol A is combined with 0.8 mol B. Twice moles of A are 0.6 moles that are lower than 0.8 moles. A IS limitng reagent.

I hope it helps!