Question

Fe(s) + 2HCl(aq) --> FeCl2(aq) + H2(g)

Answer 1

Answer:

In the option(A) moles of HCl left are 0.100 moles which is wrong, making the option incorrect.

Explanation:

$Fe(s) + 2HCl(aq)\rightarrow FeCl_2(aq) + H_2(g)$

Moles of HCl = n

Molarity of HCl = 1.0M

Volume of HCl solution = 30.0 mL = 0.030 L (1 mL = 0.001L)

$Moles=Molarity\times Volume (L)$

$n=1.0M\times 0.030 L=0.030 mol$

Moles of Fe = $\frac{0.56 g}{56 g/mol}=0.01 mol$

According to recation , 1mol of Fe reacts with 2 mol HCl. Then 0.01 mole of Fe will recat with :

$\frac{2}{1}\times 0.01 mol= 0.02 mol$ of HCl

This means that HCl uis in excess , hence excessive reagent.

Moles of HCl left unreacted :

= 0.030 mol - 0.020 mol = 0.010 mol

But in the option moles of HCl left are 0.100 moles which is wrong, making the option incorrect.