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9.8g of solid potassium chlorate (KCIO3) were add...

9.8g of solid potassium chlorate (KCIO3) were added to 40 cm3 of water and heated to dissolve all the solid. As he solution cooled, crystals of potassium chlorate started forming at 60°C. The solubility of potassium chlorate at 66°C is therefore?

A.

24.5 mole per dm3

B.

0.2 mole per dm3

C.

10.0 mole per dm3

D.

20.0 mole per dm3

E.

2.0 mole per dm3

Correct answer is E

9.8 gms KCIO3 dissolves in 40 cm3 of H.
In 100 cc we have (9.8)/(40) x (100)/(1) = 24.5 gm KCIO3

In 1000 cc we have 10 x 24.5
or 245 gms of KCIO3.
But mol wt of KCIO3 is 122.5
Solubility of KCIO3 is (245)/(122.5) = 2 moles per dm3 (E)