12 g of solid protassium chlorate (KCIO) were added to 40 g of water and heated to dissolve all the solid. As the solution cools, crystals of potassium chlorate at 66 oC. The solubility of potassium chlorate at 66 oC is therefore?

A.

66

B.

33

C.

10

D.

20

E.

30

Correct answer is E

solubility = \(\frac{solute x 100}{solvent}\)

The solubility of KClO3 at 66oC will be \(\frac{12}{40} \times \frac{100}{1}\)

= 30