Question

During the estimation of phosphorous, 5 g of an organic compound gave 2.5 g of $M{g}_2{P}_2{O}_7$. What is the percentage of phosphorous in the organic compound?

• A. 5
• B. 10
• C. 15
• D. 20

Answer 1

The correct option is C 15

During the estimation of phosphorous, 5 g of an organic compound gave 2.5 g of $M{g}_2{P}_2{O}_7$.
The percentage of phosphorous in the organic compound $=\frac{66\times \text{Wt. of}M{g}_2{P}_2{O}_7\text{formed}}{222\times \text{Wt. of the compound}}\times 100$
% of P $=\frac{66\times \text{2.5 g}}{222\times \text{5}}\times 100=14.9\simeq 15$ %