The solubility in moles per dm3 of 20g of CuSO4 dissolved in 100g of water at 180^0C is

A. 0.13

B. 0.25

C. 1.25

D. 2.00

[Cu=63.5, S=32, O=16]

The correct answer is C. 1.25

Calculation:

First, calculate the molar mass of CuSO₄:

Cu = 63.5
S = 32
O₄ = 4 × 16 = 64

Molar mass = 63.5 + 32 + 64 = 159.5 g mol⁻¹

Step 1: Find number of moles of CuSO₄

Moles = 20/159.5= 0.125 mol

Step 2: Convert volume of water to dm³

100 g of water ≈ 100 cm³ = 0.1 dm³

Step 3: Calculate solubility (mol dm⁻³)

Solubility = 0.125/0.1= 1.25 mol dm^-3

✅ Correct Answer: C. 1.25

NUMBER SIXTEEN

Tags:

Secondary>Science>>Chemistry>>>JAMB 1990

Posted by: Kingsley Thompson

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