Question

In Carius’ method of estimation of Halogen, 0.172 g of an organic compound showed the presence of 0.08 g of Bromine. Which of these is the correct structure of the compound?

• A. H₃C−Br
• B. 2,4−dibromoaniline

  

• C. p−bromoaniline
• D. bromoethane

Answer 1

The correct option is C

p−bromoaniline

Explanation:

According to the Carius method,

1. Mass percent = (mass of chemical/total mass of compound) x $100$
2. mass $\%$ of ‘$\mathrm{Br}$ =$\frac{0.08}{0.172}\times 100=\frac{8000}{172}=46.5\%$

Explanation for correct option is (C) :

Option C: $\mathrm{Br}$ mass $\%$ $=\frac{80}{172}\times 100=46.5\%$

Explanation for wrong options:

Option A: $\mathrm{Br}$ mass $\%$ $=\frac{80}{95}\times 100=84.2\%$

Option B: $\mathrm{Br}$ mass $\%$ $=\frac{2\times 80}{252}\times 100=63.5\%$

Option D: $\mathrm{Br}$ mass $\%$$=\frac{80}{109}\times 100=75.2\%$

Option C matches with the given mass percentage value.

So, the correct option is C.