Question

If density of 20w/w % aq. The solution of NaCI is 1.05gm/ml . Find the molarity of this solution?
please give step by step explanation, or your answer will be reported.

Answer 1

Explanation:

0.86 mol kg

−1

in this question 1M solution of NaNO

3

,

By definition if Molarity we know that it is the no. of moles present in per litre of solution. = 1M molar solution has 1 mole of NaNO

3

for 1000ml of solution.

Therefore, mass of solute is mass of 1 mole of NaNO

3

= 23+14+48 = 85 gm.

volume of solution = 1000 ml as per definition.

Now,Given that density is 1.25 g/cm3

Therefore, mass = 1.25×1000 (m = density X volume)

=> mass = 1250 gm (solution mass)

Mass of solvent = mass of solution - mass of solute

= 1250 - 85= 1165gm.

Molarity is the no. of mole of solute per kg of solvent

=> m =

1165

1

×1000 =

1165

1000

=0.85m