Question

10g of hydrogen and 64 g of oxygen were filled in a steel vessel and exploded. Amount to water produced in this reaction will be

• A. 3mol
• B. 4mol
• C. 1 mol
• D. 2mol

Answer 1

Answer: (D)

Moles of $ {{H}_{2}}=\frac{10}{2}=5\,\text{mol} $
Moles of $ {{O}_{2}}=\frac{64}{32}=2\,\text{mol} $
$ \underset{(5\,mol)}{\mathop{2{{H}_{2}}}}\,+\underset{(2\,mol)}{\mathop{{{O}_{2}}}}\,\xrightarrow{{}}\underset{(4\,mol)}{\mathop{2{{H}_{2}}O}}\, $
Here $ {{\text{O}}_{\text{2}}} $ is limiting reagent.
So, amount of product,
$ {{\text{H}}_{\text{2}}}\text{O} $
obtained depends on the amount of
$ {{\text{O}}_{\text{2}}}\text{.} $
According to equation, 1 mole $ {{O}_{2}} $ on reaction with $ {{H}_{2}} $ gives = 2 mole of $ {{H}_{2}}O $ 2 mole $ {{O}_{2}} $ on reaction with $ {{H}_{2}} $ will give
$ =\frac{2\times 2}{1}=4\text{mole}\,\text{of} $
Note 1 mole of $H_2$ is in excess.