If 20 cm³ of sodium hydroxide was neutralized by 20 cm³ of 0.01 mol dm³ tetraoxosulphate(VI) acid, what is the concentration of the solution?

A. 0.010 mol/dm³
B. 0.020 mol/dm³
C. 0.100 mol/dm³
D. 0.150 mol/dm³

Correct Answer:

Option B = 0.020 mol/dm³

Explanation

^CaVa/_CbVb = ^Na/_Nb

^{(0.01 X 20)} / _{(Cb X 20)} = ¹/₂

cross multiply → Cb = ^{(0.01 X 20 X 2)}/_{(20 X 1)}

Cb = 0.02 mol/dm³