Calculate the mass of sodium hydroxide in 5.00 dm³ of a 0.125 mol dm‾³ solution. [NaOH = 40 g mol‾¹]

A. 0.0156 g
B. 0.625 g
C. 1.00 g
D. 25.0 g

Correct Answer: Option D

D. 25.0 g

Explanation

1 mole of NaOH per dm³ has a mass of 40g.
mass of NaOH in 0.125mole
= 0.125 x 40 = 5g.
mass in 5.00 dm3 of the solution.
= 5 x 5 = 25.0g.