Question

Hydrochloric acid reacts with calcium to form hydrogen and calcium chloride. If 100 grams of hydrochloric acid reacts with 100 grams of calcium, what is the limiting reactant? 2HCl + Ca → CaCl2 + H2

Answer 1

Answer:- The limiting reactant is HCl.

Explanation: The balanced equation is:

$2HCl+Ca\rightarrow CaCl_2+H_2$

It's a stoichiometry problem. Masses of both the reactants are given and the questions asks to find out the limiting reactant.

We convert the given grams of each reactant to moles on dividing by its molar mass. Now, we can calculate the moles of any of the product on multiplying the moles of the reactant by mole ratio.

We do this starting with both the reactants and see which one gives less number of moles of the product. The limiting reactant is the one giving least number of moles of the product.

Molar mass of HCl is 36.46 gram per mol and that of Ca is 40.08 gram per mol.

Let's say we calculate the moles of hydrogen gas produced in the reaction. Mole ratio of $H_2$ to HCl is 1:2 and the mole ratio of $H_2$ to Ca is 1:1 .

The calculations are as shown below:

$100gHCl(\frac{1molHCl}{36.46gHCl})(\frac{1molH_2}{2molHCl})$

= 1.37 mol [tex[H_2[/tex]

$100gCa(\frac{1molCa}{40.08gCa})(\frac{1molH_2}{1molCa})$

= 2.50 mol $H_2$

From above calculations, we get the least moles of hydrogen gas from 100 grams of HCl. So, the limiting reactant is HCl.

Answer 2

Answer is hydrochloric acid

Hope this helps!