Answer:
CaCO3(s) <==> Ca2+(aq) + CO3 2-(aq)
Let X = the amount of CaCO3 dissolved in Na2CO3 or the amount of each ions formed i.e. Ca2+ and CO3 2–. Then, put this into the formula :
Ksp = [Ca2+] [CO3 2-]
5 × 10^-9 = [X]*[X]
X^2 = 5 × 10^-9
X = √5 × 10^-9
X = 7.07 x 10^-5 mole/L
So, the amount of CaCO3 dissolved in 0.1M Na2CO3 or the amount of Ca2+ and CO3 2- ions produced is 7.07 x 10^-5 mole/L
