MarksRiser
MarksRiser
Chemistry-(general)

NEET Chemistry (general) MCQ Question

Type: MCQ-numerical-Hard-Class 12

Given that 1 g of compound AB2 lowers the freezing point of benzene by 2.3 K and 1 g of AB4 lowers it by 1.3 K, calculate the atomic mass of element A if the atomic mass of B is 10 g/mol and the molar depression constant for benzene is 5.1 K kg mol⁻¹.

A

20 g/mol

B

30 g/mol

C

40 g/mol

D

50 g/mol

Correct Answer

Option A

Detailed Explanation

Using the formula ΔTf = Kf * m, where m is the molality, we find the molar mass of AB2 and AB4 and solve the system of equations. Given atomic mass of B = 10 g/mol, we compute atomic mass of A as 20 g/mol.

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