Question

Calculate the molarity of NaOH in the solution prepared by dissolving its 4g in enough water to form 250ml of the solution.

Answer 1

molarity =moles/lit
moles of NaOH in 4g =0.1 moles hence 
molarity =0.1/250/1000
=0.1/25*100
=0.1*4
=0.4mole/lit

Answer 2

HEYA MATE HERE U GO.

WNaOH = 4gm

v= 250ml

GMW= 40

M= ?

M= w/GMW × 1000/V(ml) = = 4/40 × 1000/250 = 0.4M.