When 45 g of an unknown compound was dissolved in 500 g of water, the solution has freezing point of `-0.93^(@)C`
(i) What is the molecular weight of compound ? `(K_(f)=1.86)`
(ii) If empirical formula is `CH_(2)O`, what is the molecular formula of compound ?

Options

A. 5
B. 6
C. 7
D. 8

Answer

C

Explanation

(1)`CH_(3)-CH_(2)-CH_(2)-CH_(2)-CHO` , (2)`CH_(3)-CH_(2)-undersetunderset(CH_(3))(|)(CH)-CHO` , (3)`CH_(3)-undersetunderset(CH_(3))(|)(CH)-CH_(2)-CHO`
(4)`CH_(3)-undersetunderset(CH_(3))(|)oversetoverset(CH_(3))(|)(C)-CHO` , (5)`CH_(3)-undersetunderset(O)(||)(C)-CH_(2)-CH_(2)-CH_(3)` (6)`CH_(3)-undersetunderset(O)(||)(C)-undersetunderset(CH_(3))(|)(CH)-CH_(3)`
(7)`CH_(3)-CH_(2)-undersetunderset(O)(||)(C)-CH_(2)-CH_(3)`