Question

When 9.8 mol Fe react with 11.5 mol HCl, what is the limiting reactant and how many moles of H2 can be formed?

unbalanced equation: Fe + HCl yields FeCl3 + H2

HCl is the limiting reactant, and 3.83 mol H2 can be formed
Fe is the limiting reactant, and 4.90 mol H2 can be formed
HCl is the limiting reactant, and 5.75 mol H2 can be formed
Fe is the limiting reactant, and 14.7 mol H2 can be formed

Answer 1

Answer: The correct answer is HCl is the limiting reactant, and 5.75 mol
`H_2` can be formed.

Step-by-step explanation:

Limiting reagent is defined as the reagent that is present in less amount and it also limits the formation of products.

Excess reagent is defined as the reagent that is present in large amount in the reaction.

For the given chemical reaction:

`2Fe+6HCl\rightarrow 2FeCl_3+3H_2`

By stoichiometry of the reaction:

6 moles of hydrochloric acid reacts with 2 moles of iron

So, 11.5 moles of hydrochloric acid will react with =
`(2)/(6)* 11.5=3.83moles` of iron.

As, the required amount of iron is more than the given amount. Thus, it is considered as an excess reagent.

Hence, hydrochloric acid is considered as a limiting reagent because it limits the formation of product.

By stoichiometry of the reaction:

6 moles of hydrochloric acid produces 3 moles of hydrogen gas.

So, 11.5 moles of hydrochloric acid will produce =
`(3)/(6)* 11.5=5.75moles` of hydrogen gas.

Hence, the correct answer is HCl is the limiting reactant, and 5.75 mol
`H_2` can be formed.

Answer 2

To answer the question, we first balance the given chemical reaction. Such that,
2Fe + 6HCl --> 2FeCl3 + 3H2
For every 2 mols Fe, 6 mols HCl is needed. From the given amounts,
9.8 mols of Fe needs 29.4 mols HCl. Since, there will be an anticipated lack of HCl, the limiting reactant is HCl. For 11.5 mols HCl, only 3.83 mols Fe is needed. This reaction will yield 5.75 mols H2. The answer is the third choice.