Question
$$10 g$$ of hydrogen and $$64 g$$ of oxygen were filled in a steel vessel and exploded. Amount of water produced in this reaction will be
A.
$$2\,moles$$
B.
$$3{\text{ }}moles$$
C.
$$4\,moles$$
D.
$$1\,mole$$
Answer :
$$4\,moles$$
Solution :
\[\underset{\underset{\begin{align}
& \\
& \\
& \frac{10}{2}\,mol \\
& \\
& 5\,mol \\
\end{align}}{\mathop{\begin{smallmatrix}
\\
\\
1\,mol
\end{smallmatrix}}}\,}{\mathop{{{H}_{2}}}}\,+\underset{\underset{\begin{align}
& \\
& \frac{64}{32}mol \\
& \\
& 2\,mol \\
\end{align}}{\mathop{\begin{smallmatrix}
\\
\frac{1}{2}mol
\end{smallmatrix}}}\,\,}{\mathop{\frac{1}{2}{{O}_{2}}}}\,\to \underset{\underset{\begin{align}
& \\
& \\
& \\
& ? \\
\end{align}}{\mathop{\begin{smallmatrix}
\,\, \\
\\
1\,mol
\end{smallmatrix}}}\,}{\mathop{{{H}_{2}}O}}\,\]
$$\eqalign{
& \because \,\,\frac{1}{2}mole\,{\text{of}}\,{O_2}\,{\text{gives}} \cr
& = 1\,mole\,{\text{of}}\,{H_2}O \cr
& \therefore \,\,2\,moles\,{\text{of}}\,{O_2}\,{\text{will}}\,{\text{give}} \cr
& = 1\, \times 2 \times 2 \cr
& = 4\,moles\,{\text{of}}\,{\text{water}} \cr} $$