In Carius method for estimation of halogens, 0.2 g of an organic compound gave 0.188 g of AgBr. The percentage of bromine in the compound is . (Nearest integer)

[Atomic mass: Ag = 108, Br = 80]

Question

In Carius method for estimation of halogens, 0.2 g of an organic compound gave 0.188 g of AgBr. The percentage of bromine in the compound is . (Nearest integer)

[Atomic mass: Ag = 108, Br = 80]

Canvas Classes · Accepted Answer

Step 1: Recall Carius Method for Bromine

Where molar mass of  = 108 + 80 = 188 g/mol

Step 2: Substitute Given Values

-  = 0.188 g
-  = 0.2 g

Step 3: Calculate Percentage

Answer: 40 (nearest integer)

Elegant alternative:

Notice: , so the ratio  and , giving .

Key Points to Remember:
- 
- The nice numbers here (0.188 g AgBr, 0.2 g compound) should signal that %Br will be a clean number
- If %Br is 40% and MW of compound is known, we can infer structure

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