Zinc metal reacts with aqueous hydrochloric acid to produce zinc chloride and hydrogen gas. Zn (s) + 2 HCl (aq) $\rightarrow$ ZnCl₂ (aq) + H₂ (g)
What volume of 3.55-M HCl is required to produce 25.5 L of hydrogen gas at a temperature of 298 K and a pressure of 1.20 atm?

Question

Zinc metal reacts with aqueous hydrochloric acid to produce zinc chloride and hydrogen gas. Zn (s) + 2 HCl (aq)

\rightarrow

ZnCl₂ (aq) + H₂ (g)
What volume of 3.55-M HCl is required to produce 25.5 L of hydrogen gas at a temperature of 298 K and a pressure of 1.20 atm?

Quizplus · Accepted Answer

First, we need to use the ideal gas law to calculate the number of moles of hydrogen gas produced:

PV = nRT

n = (PV) / RT

n = (1.20 atm) * (25.5 L) / (0.0821 L*atm/mol*K * 298 K)

n = 1.084 mol

According to the balanced chemical equation, 1 mole of hydrogen gas is produced for every 2 moles of HCl used:

Zn (s) + 2 HCl (aq) → ZnCl2 (aq) + H2 (g)

So, we need 2.168 mol of HCl to produce 1.084 mol of H2.

Finally, we can use the molarity of the HCl solution to determine the volume needed:

M = n/V

V = n/M

V = 2.168 mol / 3.55 mol/L

V = 0.705 L

Therefore, the answer is choice C, 0.705 L of 3.55 M HCl is required.

Zinc Metal Reacts with Aqueous Hydrochloric Acid to Produce Zinc →\rightarrow→