The amount of arsenic pentasulhide that can be obtained when `35.5g` arsenic acid is treated with axess `H_(2)S` in the presence of conc. `HCl` `("assuming" 100% "conversion")` is :

Options

A. 0.50 mol
B. 0.25 mol
C. 0.125 mol
D. 0.333 mol

Answer

C

Explanation

Moles of arsenic acid in 35.5 gm = 0.25 according to given reaction 2 moles of arsenic acid give 1 mole `As_(2)S_(5)` therefore 0.25 moles of arsenic acid will give 0.125 mole.