Question

Calculate the molarity of a solution obtained by mixing 50 mL of 0.5 M H₂SO₄ and 75 mL of 0.25 M H₂ SO₄.

(a)  0.375 M

(b)  0.35  M

(c)  0.045 M

(d)  0.45  M

Answer 1

Correct option (b)

Explanation:

No.of moles of 0.05 L H₂SO₄ = 0.5 x 0.05 = 0.025 

No.of moles of 0.075 L H₂SO₄ = 0.25 x 0.075 = 0.01875

:. Total no. of moles = 0.025 + 0.01875 = 0.04375 

Total vol = 0.05 L + 0.075 L = 0.125 L

:.  Molarity = 0.04375/0.125 = 0.35 M