Question

For "16.8 V" H2O2 solution ( density = 0.95 g/ml), calculate :- 1. Molarity 2. Molality 3. % w/w 4. % w/v 5. ppm of solute 6. mole fraction of solute

Answer 1

A sample of H2O2 solution lebelled as 16.8 volume has density 0.95 g/ml.

To find :

1. Molarity
2. Molality
3. percentage w/w
4. percentage w/v
5. ppm of solute
6. mole fraction

solution : Molarity = volume strength/11.2

= 16.8/11.2

= 1.5

Molarity of H2O2 solution is 1.5 M, it means 1.5 moles of H2O2 present in 1000 ml of solution.

so, mass of solvent = volume of solution × density of solution

= 1000 ml × 0.95 g/ml

= 950 g

now Molality = no of moles of solute/mass of solvent in kg

= 1.5 × 1000/950

= 150/95

= 1.58 molal

percentage w/w = mass of solute/mass of solution × 100

mass of solute = 1.5 × 34 = 51 g

mass of solution = 950g + 51 g = 1001g

now percentage w/w = 51/1001 × 100

= 5.0949 %

percentage w/v = mass of solute/volume of solution × 100

51/1000 × 100

= 5.1 %

ppm of solute = mass of solute/mass of solution × 10⁶

= 51/1001 × 10⁶

= 0.050949 × 10⁶

= 5.0949 × 10⁴

mole fraction of solute = 1.5/(1.5 + 950/18) [ mole of solvent = 950/18 ]

= 1.5/(1.5 + 52.78)

= 1.5/54.28

= 0.02763