Use your experimentally determined value of ksp and show, by calculations, that ag2cro4 should precipitate when 5ml of 0.004m agno3 are added to 5ml of 0.0024 m k2cro4.

When the value of Ksp = 3.83 x 10^-11 (should be given - missing in your Q)

So, according to the balanced equation of the reaction:

and by using ICE table:

Ag2CrO4 (s) → 2Ag + (Aq) + CrO4^2 - (aq)

initial 0 0

change + 2X + X

Equ 2X X

∴ Ksp = [Ag+]^2[CrO42-]

so by substitution:

∴ 3.83 x 10^-11 = (2X) ^2 * X

3.83 x 10^-11 = 4 X^3

∴X = 2.1 x 10^-4

∴[CrO42-] = X = 2.1 x 10^-4 M

[Ag+] = 2X = 2 * (2.1 x 10^-4)

= 4.2 x 10^-4 M

when we comparing with the actual concentration of [Ag+] and [CrO42-]

when moles Ag + = molarity * volume

= 0.004 m * 0.005L

= 2 x 10^-5 moles

[Ag+] = moles / total volume

= 2 x 10^-5 / 0.01L

= 0.002 M

moles CrO42 - = molarity * volume

= 0.0024 m * 0.005 L

= 1.2 x 10^-5 mol

∴[CrO42-] = moles / total volume

= (1.2 x 10^-5) mol / 0.01 L

= 0.0012 M

by comparing this values with the max concentration that is saturation in the solution

and when the 2 values of ions concentration are >>> than the max values o the concentrations that are will be saturated.

∴ the excess will precipitate out