Question

At 25 ∘C the reaction CaCrO4(s)←→Ca2+(aq)+CrO2−4(aq) has an equilibrium constant Kc=7.1×10−4. What is the equilibrium concentration of Ca2+ in a saturated solution of CaCrO4?

Answer 1

2.67 × 10⁻²

Step-by-step explanation:

Equation for the reaction is expressed as:

CaCrO₄(s) ⇄ Ca₂⁺(aq) + CrO₂⁻⁴(aq)

Given that:

Kc=7.1×10⁻⁴

Kc=
`[Ca^(2+)][CrO^(2-)_4]`

Kc= [x][x]

Kc= [x²]

7.1×10⁻⁴ = [x²]

x =
`\sqrt{7.1*10^(-4)}`

x = 0.0267

x =
`2.67*10^(-2)`