Question

The reaction of calcium with water is represented by the equation $Ca+2H_{2}O\to Ca(OH{)}_2+H_2$ What volume of $H_2$, at STP would be liberated when 8 g of calcium completely reacts with water

• A. 4480 $c{m}^3$
• B. 2240 $c{m}^3$
• C. 1120 $c{m}^3$
• D. 0.4 $c{m}^3$

Answer 1

Answer: (A)

$\underset{\text{40}}{\mathrm{Ca}}+2H_{2}O\to Ca(OH{)}_2$+ $\underset{\text{22400cm3}}{H_2}$
$8g$ of calcium will produce $=\frac{22400\times 8}{40}$
$=4480c{m}^3$