An organic compound is known to contain 40 % bromine by mass. When subjected to halogen estimation by the Carius method, a sample of this compound produced 0.94 g of silver bromide ( AgBr ) precipitate. The mass of the organic compound taken for the estimation is: (Given molar masses: Ag = 108 g mol ⁻¹ , Br = 80 g mol ⁻¹ )

Step-by-step solution

Molar mass of AgBr = 108 + 80 = 188 g mol ⁻¹ Moles of AgBr precipitate formed = 0.94 188 = 0.005 mol Mass of bromine present in the precipitate = 0.005 80 = 0.40 g Let the mass of the organic compound taken be W . Since the compound contains 40 % bromine by mass, the mass of bromine can also be expressed as: Mass of Br = 40 100 W Equating the two values for the mass of bromine: 0.40 = 0.40 W W = 1.00 g Answer: 1.00 g