Question

Molarity of 4% (W/V) solution of NaOH is ​

Answer 1

Answer:

We assume that 4gm mass of NaOh is dissolved in 100ml volume of water and such a dissolution would involve minimal change to the volume of solution. Then Molarity=mole of solute/volume of solution in litre. , Molarity=4×1000/40×100 =1mole/litre.

Answer 2

Mass of NaOH in 100ml solution = 4g

Mass of NaOH in 1000ml (1L) solution = 40g

$\pink{Moles~of~NaOH}= \dfrac{Given \: mass}{Molar \: mass} = \dfrac{40}{40} = 1 \: mole$

$\pink{Molarity} = \dfrac{No.\: of \: moles}{Volume} = \dfrac{1}{1} = \green{1~mol/L}$