Can u plz help me with this ksp problem...i just need the steps?

Question

How many mL of a 0.001 M chloride solution must be added to a 100mL solution of 7.2 x 10^ -5 M Ag+ solution for AgCl to precipitate? Ksp (AgCl)= 1.8 x 10^ -10.

.25mL

Answer 1

a rough calculation, without considering any dilution, first:

Ksp = [Ag+] Cl-]

1.8e-10 = [7.2e-5] Cl-]

Cl- = 2.5 e-6 molar is needed to saturate the solution

------------------------------

find the moles that needs to be in the 100 mls of Ag+ solution:

0.100 litres @ 2.5e-6 mol/litre = 2.5e-7 moles fo Cl-

find the number of litres  of 0.001M Cl- solution which has those moles:

2.5e-7 moles @ 0.001moles / litre = 2.5e-4 litres of 0.001MCl- solution

find the # of millilitres:

2.5e-4 litres = 0.25 millilitres

the volume that needs to be added does not appreciably dilute the 100ml of silver solution....

your answer is 0.25 millilitres of 0.001 molar Cl- needs to be added