Question

In the reaction given below:
$3H_{3}P{O}_2\to {PH}_3+2H_{3}P{O}_3$
How many grams of ${PH}_3$ will be formed on decomposition of $6$ moles of $H_{3}P{O}_2$?

[Given: Atomic mass of phosphorus $=31$, hydrogen $=1$ g/mol]

• A. $34$ g
• B. $68$ g
• C. $17$ g
• D. $6$ g

Answer 1

The correct option is B $68$ g

The equation is as follows:
$3H_{3}P{O}_2\to {PH}_3+2H_{3}P{O}_3$

$3$ moles of $H_{3}P{O}_2$ gives $1$ moles of $P{H}_3$.

$6$ moles of $H_{3}P{O}_2$ gives $2$ moles of $P{H}_3$.

Mass of $P{H}_3=2\times 34=68g$

Hence, option B is correct.