What is the mass of solute in 500cm³ of 0.005moldm¯³ H2SO4? ( H = 1, S = 32.0, O=16.0)?

A. 0.490g
B. 0.049g
C. 0.245g
D. 0.0245g

Correct Answer: Option A

Explanation

500cm³=0.005moldm−³

1000cm³=0.005500×1000cm³=0.010moldm‾³
Molar concentration = mass (in gdm‾³) / molarmass (in gmol‾¹)
0.01moldm‾³ = mass in gdm−398.0gmol−1
(Molar mass of H2SO4 = (2×1) + 32 + (16×4) = 98)

mass in gdm−3 = 0.980/gdm−3

1000cm3=0.980g
500cm3=0.980 x 500/1000=0.490g