Question

The mass of NaOH present per dm of 0.25M NaOH solution is

Answer 1

molarity=0.25 M L-1

molarity=(mols of solute)/litres of solution.

litres of solution= 1 dm3 =>1/10 * 1000 litres =>100 litres

0.25=mols of solute/100

mols of solute=25 mol of NaOH

molar mass of NaOH=23+16+1

=> 40 g mol-1

Hence, mass of NaOH used=40*25 g

mass of NaOH=1000 g or 1 kg