Question

Using Carius method, find out the percentage of bromine in the compound if 0.450 g of organic compound gave 0.200 g of AgBr. (Given: molar mass of Ag = 108; molar mass of Br = 80)

(a) 18%

(b) 17%

(c) 17.68%

(d) 18.91%

This question was addressed to me in semester exam.

Question is from Organic Chemistry in chapter Organic Chemistry – Basic Principles and Technique of Chemistry – Class 11

Answer 1

The correct choice is (d) 18.91%

For explanation: The molar mass of AgBr = 108 + 80

= 188 g

So, 188 g of AgBr contains 80 g of Br.

Then, 0.200 g of AgBr contains 80 * 0.200/ 188 = 0.085 g  bromine

Therefore, percentage of bromine = 0.085 * 100/ 0.450

                                                              = 18.91%

Thus, the percentage of bromine (halogen) using Carius method is 18.91%.