If a dilute agno3 solution is slowly added to the solution, what is the first compound to precipitate: ag2cro4 ( ksp = 1.2×10−12), ag2co3 ( ksp = 8.1×10−12), or agcl ( ksp = 1.8×10−10)?

The question is missing the initial information required to answer but that information is provided below:

"A solution contains three anions with the following concentrations, 0.20 M CrO₄²⁻, 0.10 M CO₃²⁻ and 0.01M Cl⁻."

Ag₂CrO₄ Ksp = 1.2 x 10⁻¹²
Ag₂CO₃  Ksp = 8.1 x 10⁻¹²
AgCl      Ksp = 1.8 x 10⁻¹⁰

With the following information we can calculate the minimum amount of Ag⁺ needed to precipitate each solid.

AgCl → Ag⁺ + Cl⁻

Ksp = [Ag⁺][Cl⁻] = 1.8 x 10⁻¹⁰
[Ag⁺] = 1.8 x 10⁻¹⁰ / 0.01 M
[Ag⁺] = 1.8 x 10⁻⁸ M

Ag₂CrO₄ → 2Ag⁺ + CrO₄²⁻

Ksp = [Ag⁺]²[CrO₄²⁻] = 1.2 x 10⁻¹²
[Ag⁺]² = 1.2 x 10⁻¹² / 0.20 M
[Ag⁺] = √(1.2 x 10⁻¹² / 0.20 M)
[Ag⁺] = 2.4 x 10⁻⁶ M

Ag₂CO₃ → 2Ag⁺ + CO₃²⁻

Ksp = [Ag⁺]²[CO₃²⁻] = 8.1 x 10⁻¹²
[Ag⁺]² = 8.1 x 10⁻¹² / 0.10 M
[Ag⁺] = √(8.1 x 10⁻¹² / 0.q0 M)
[Ag⁺] = 9.0 x 10⁻⁶ M

AgCl requires the minimum amount of [Ag⁺] to precipitate with a value of [Ag⁺] = 1.8 x 10⁻⁸ M

Therefore, AgCl will precipitate first.