Question

Calculate the weight of iron which will be coverted into its oxide by the action of $18\text{g}$ of steam on it.

• A. $37.3\text{g}$
• B. $42\text{g}$
• C. $56\text{g}$
• D. $5.6\text{g}$

Answer 1

The correct option is B $42\text{g}$

$3Fe+4H_{2}O\to F{e}_3{O}_4+4H_2$
$72\text{g}$ of $H_{2}O\left(g\right)$ convert $168\text{g}$ $Fe$ to its oxide
$18\text{g}$ of $H_{2}O\left(g\right)$ will convert $\frac{168}{72}\times 18=42\text{g}$ $Fe$ to its oxide