Question

Aqueous solution of naoh is marked 10 (w/w) the density of solution is 1.070g cm3 calculate molarity

Answer 1

Answer:

Molarity = 2.675 M

Molality = 2.777 m

Mole fraction (NaOH) = 0.0476

Mole fraction (H2O) = 0.9523

Explanation:

aqueous solution of NaOH is marked 10%(w/w). Dwnsity of solution is 1.070 gm/cm^3.

(i) Molarity -

Molarity = no of moles of solute / volume of soln

Molarity = (10/40) / (0.1÷1.07)

Molarity = 2.675 M

(ii) Molality -

Molality = no of moles of solute / mass of solvent

Molality = (10/40) / (0.090)

Molality = 2.777 m

(iii) Mole fraction of NaOH -

Mole fraction (NaOH) = moles of NaOH / total moles

Mole fraction (NaOH) = (10/40) / (10/40 + 90/18)

Mole fraction (NaOH) = 0.0476

(iv) Mole fraction of H2O -

Mole fraction (H2O) = moles of H2O / total moles

Mole fraction (H2O) = (90/18) / (10/40 + 90/18)

Mole fraction (H2O) = 0.9523