How much sodium hydroxide is required to make 250 cm3 of 0.1 molar solution? Na=23; 0=16; H=1]

A.

10.0 g

B.

4.0g

C.

2.0 g

D.

1.0g

E.

0.1 g

Correct answer is D

no of moles of Na = molar concentration X   volume

                             = 0.1 x \(\frac{250}{1000}\) = 0.025

no of moles =  \(\frac{m}{M}\) 

mass = no of mles x molar mass = 0.025 x 40 = 1.0g ( molar mass of NaOH = 40g/mol)