What is the concentration of a solution containing 2g of NaOH in 100cm³ of solution? [Na=23, O=16, H=1]

A. 0.05 moldm-³
B. 0.30 moldm-³
C. 0.50 moldm-³
D. 0.40 moldm-³

Correct Answer:

Option C – 0.50 moldm-³

Explanation

2g NaOH is contained in 100cm³
Xg NaOH is contained in 1000cm³

Xgram = (2×1000)/100

= 20g

Mole = 20/40 = 0.50mol/dm³