Question

the solubility of As2s3 is 2.8*10^-72.what is solubilty in mol/l of As2As2s3. options- (a)1.74*10^-16. (b) 1.29 *10^-30 (c) 1.92 *10^-15 (d) 1 *10^-36​

Answer 1

Given:

The solubility product (Ksp) of As₂S₃ is equal to 2.8*10⁻⁷²

To find:

The solubility (s) of As₂S₃ in mol/l.

Solution:

• Each mole of As₂S₃ produces two moles of As³⁺ ions and three moles of S²⁻ ions.
• The concentration of As³⁺ ions will be equal to 2s and the concentration of S²⁻ ions will be equal to 3s.
• Ksp = [As³⁺]².[S²⁻]³ = (2s)².(3s)³ = 108s⁵
• Hence, s = (Ksp/108)^(1/5) = 1.92*10⁻¹⁵ mol/L

Answer:

The solubility of As₂S₃ is equal to 1.92*10⁻¹⁵ mol/L