# Problem: In which solution(s) will a precipitate form? I. 0.00090 g of Na 2CrO 4 (molar mass = 162.0 g/mol) is added to 225 mL of 0.00019 M AgNO 3. Ksp Ag 2CrO 4 = 1.1 x 10 -12 II. 0.100L of 0.0015 M MgCl 2 and 0.200L of 0.012 M NaF. Ksp MgF 2 = 3.7 x 10 -8 a. I - no; II - nob. I - yes; II - noc. I - no; II - yesd. I - yes; II - yes

###### FREE Expert Solution

We’re being asked to determine which precipitate will form given in the given solutions for MgF2 and Ag2CrO4

For this, we need to compare the reaction quotient (Q) vs. the solubility product constant (Ksp). Recall that when:

• Q > Ksp: the solution is supersaturated and a precipitate will form. Reactants are favored.

• Q = Ksp: the solution is at equilibrium and no precipitate will form.

• Q < Ksp: the solution is unsaturated and no precipitate will form. Products are favored.

In this case, we need to follow each step:

Step 1. Setup the reaction quotient expression

Step 2. Determine the concentrations of each species involved in the precipitation

Step 3. Calculate for Q

Step 4. Compare it to Ksp ###### Problem Details

In which solution(s) will a precipitate form?

I. 0.00090 g of Na 2CrO 4 (molar mass = 162.0 g/mol) is added to 225 mL of 0.00019 M AgNO 3. Ksp Ag 2CrO 4 = 1.1 x 10 -12

II. 0.100L of 0.0015 M MgCl 2 and 0.200L of 0.012 M NaF. Ksp MgF 2 = 3.7 x 10 -8

a. I - no; II - no

b. I - yes; II - no

c. I - no; II - yes

d. I - yes; II - yes