Question

The drain cleaner, Drainex contains small bits of aluminum which react with caustic soda to produce dihydrogen. What volume of dihydrogen at ${20}^{\circ }C$ and one bar will be released when $0.15g$ aluminum is allowed to react?

• A. $202.6ml$
• B. $102.5ml$
• C. $101.25ml$
• D. $405.0ml$

Answer 1

The correct option is A $202.6ml$

$2Al+2NaOH+2H_{2}O\to 2NaAl{O}_2+3H_2\uparrow$
According to the reaction
$2mol\text{of}Al\text{release 3 moles of}{H}_2$
$\frac{0.15}{27}mol\text{of}Alrelease\frac{3\times 0.15}{2\times 27}$ mol of $H_2$
According to ideal gas equation: $PV=nRT$
$\Rightarrow$$V=\frac{nRT}{P}=\frac{3\times 0.15\times 0.083\times 293}{2\times 27\times 1}L$
$V=0.202L=202.6ml$