The value of K _ s p of CaCO ₃ and CaC ₂ O ₄ are 4.7 10⁻⁹ and 1.3 10⁻⁹ respectively at 25^ C . If the mixture of these two is washed with water, what is the concentration of Ca ²⁺ ions in water?

Step-by-step solution

aligned CaCO ₃ & Ca ²⁺+ CO ₃ ²⁻ CaC ₂ O ₄ & Ca ²⁺+ C ₂ O ₄²⁻ y & [ Ca ²⁺ ] & =x+y x(x+y) & =4.7 10⁻⁹ y(x+y) & =1.3 10⁻⁹ aligned aligned & x y =3.6 & x=3.6 y & y(3.6 y+y)=1.3 10⁻⁹ & y=1.6 10⁻⁵ & [ Ca ²⁺ ] =(x+y)= (1.6 10⁻⁵ ) &+ (5.76 10⁻⁵ ) &=7.46 10⁻⁵ M aligned