Question

4g/l solution or Naol is given. The molarity of the solution is ....... M. (Molecular mass of
Naon = 40 g/mol)
(A) 160
(B) 10
(C)0.1
(D) 4​

Answer 1

Answer:

D. 4 MOLAR

Explanation:

MOLARITY MEANS MASS OF SOLUTE BY VOLUME OF SOLUTION IN LITRE.

HERE YOU HAVE 4 GRAM NAOH IN 1 LITRE OF ITS SOLUTION.

THEREFORE MASS OF SOLUTE= 4 g

VOLUME OF SOLUTION =1 L

THEREFORE MOLARITY=MASS OF SOLUTE/VOL. OF SOLUTION( IN L)

= 4 MOLAR.

Answer 2

4 g/L solution means

4 g of NaOH in 100 mL solution

Vol of soln =100 mL = 0.1 L

mass of NaOH = 4g

molar mass NaOH =40 g

moles of NaOH

= mass / molar mass

=4/40

=0 .1 moles

Molarity

= moles of NaOH /Volume of soln in Litre

= 0 .1 /0 .1

=1 M

Molarity = 1 M