Question

Calculate the concentration of a solution which contains 2.5g of salt dissolved in 50g of water

Answer 1

Mass solute÷ mass of solution×100

2.5÷50×100

25÷5

=5Precent

Answer 2

Given:

2.5g of salt dissolved in 50g of water.

To Find:

The concentration of a solution.

Solution:

To find the concentration we will follow the following steps:

Concentration expressed in molarity is defined as the number of moles of a substance or solute existing in one litre of solution.

Concentration expressed in molality is defined as the number of moles of solute added to 1kg of solvent.

Let the salt NaCl so molecular weight is 58.5g.

So,

Molality

$= \frac{solute \: in \: gram \times 1000}{molecular \: weight \: \times mass \: of \: solvent}$

$= \frac{2.5 \times 1000}{58.5 \times50}$

$= 0.85$

Henceforth, the molality of 2.5g of salt dissolved in 50g of water is 0.85m.