Question

0.99 g of an organic compound containing halogen when heated with fuming $HN{O}_3$ in presence of $Ag{NO}_3$ in a carius tube gave 0.287 g of white precipitate. The percentage of halogen is?

• A. 29.6
• B. 71.7
• C. 35.4
• D. 64.2

Answer 1

Answer: (B)

71.7

If mass of organic compound= $M$

Mass of $AgX$ formed= $M_1$

$\because 1mol$ of $AgX$ has $1mol$ of $X$

$\therefore$ % of halogen= $\frac{\text{Atomic mass of}X\times M_1}{\text{Molecular mass of}AgX\times M}\times 100$

For given case, $X=Cl,M=0.99,M_1=0.287$

$\therefore$ % halogen= $\frac{35.5\times 0.287}{143.5\times 0.99}\times 100\approx 71.7$%