A 5.82 g silver coin is dissolved in nitric acid. When sodium chloride is added to the solution, all the silver gets precipitated as AgCl. The mass of the precipitated silver chloride is 7.2 g. The percentage of silver in the coin is :

Options

A. `98%`
B. `93.1%`
C. `86%`
D. `82%`

Answer

B

Explanation

Fraction of Ag in AgCl=`107.9/143.3=0.753`
weight of Ag in 7.20 g AgCl = 0.753 x 7.20 g = 5.42 g Ag
Hence the 5.82 g coin contains 5.42 g Ag =0
Fraction of Ag in coin =5.42 g/5.82 g =0.931 = 93.1% Ag