Question

consider the reaction of zinc metal with hydrochloric acid, hcl(aq).
zn(s) + 2 hcl(aq) -> h₂(g) + zncl₂(aq)
calculate the moles of hcl needed to react completely with 8.25 moles of zinc.
a 8.25 moles
b 0.242 moles
c 4.12 moles
d 16.5 moles

Explanation:

Step1: Analyze the mole ratio

From the balanced equation \(Zn(s)+2HCl(aq)\to H_2(g)+ZnCl_2(aq)\), the mole ratio of \(Zn\) to \(HCl\) is \(1:2\).

Step2: Calculate moles of \(HCl\)

If \(n(Zn) = 8.25\) moles, and \(\frac{n(HCl)}{n(Zn)}=\frac{2}{1}\), then \(n(HCl)=2\times n(Zn)\).
Substitute \(n(Zn) = 8.25\) moles into the formula: \(n(HCl)=2\times8.25\) moles.
\(n(HCl)=16.5\) moles.

Answer:

D. 16.5 moles