What volume of 0.20 mol dm‾³ NaOH solution would yield 5.0g of NaOH on evaporation to dryness? [NaOH = 40g mol‾¹]

A. 400 cm³
B. 625 cm³
C. 1000 cm³
D. 1600 cm³

Correct Answer: Option B

B. 625 cm³

Explanation

Conc. g/dm³ = 0.20 x 40 gmol -1 = 8 g/dm³

1000 cm³ of 0.20m NaOH contains 8g of NaOH :. 5g of NaOH will be contained in 5/8 x 1000 x 625cm³