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: Option E
Explanation
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)