One `dm^(3)` solution containing `10^(-5)` moles each of `Cl^(-)` ions and `CrO_(4)^(2-)` ions is treated with `10^(-4)` moles of silver nitrate. Which one of the following observations is made ?
`[K_(sp)Ag_(2)CrO_(4)=4xx10^(-12)]`
`[K_(sp)AgCl=1xx10^(-10)]`

Options

A. Precipitation does not occur.
B. Silver chromate gets precipitated first
C. silver chloride gets precipitated first.
D. Both silver chromate and silver chloride start precipitating simultaneously.

Answer

C

Explanation

Ionic product of `AgCl=[10^(-4)][10^(-5)]=10^(-9)`
Ionic product of `Ag_(2)Cr_(4)=[10^(-8)][10^(-5)]=10^(-13)`
Ionic product of `AgClgtK_(sp)` of `AgCl`
So, precipitation will take place. Ionic product of `Ag_(2)CrO_(4)ltK_(sp)` of `Ag_(2)CrO_(4)`
So, precipitation will not take place.