(1) 34.2 g of glucose is dissolved in 400 g of water. Calculate percentage by mass of glucose solution. (7.87 w/w)
(2) A solution is prepared by dissolving certain amount of solute in 500 g of water. The percentage by mass of a solute in solution is 2.38. Calculate mass of solute. (12.19g)
(3) 4.6 cm3 of methyl alcohol is dissolved in 25.2 g of water. Calculate
(i) % by mass of methyl alcohol
(ii) mole fraction of methyl alcohol and water. (Given density of methyl alcohol = 0.7952 gcm–3 and C = 12. H = 1, O = 16)
(i) 12.68 (ii) 0.0755, 0.9245
(4) 12.8 cm3 of benzene is dissolved in 16.8 cm3 of xylene. Calculate % by volume of benzene (43.24)
(5) Calculate mole fraction of HCL is solution of HCl containing 24.8% of HCl by mass. (H = 1, Cl = 35.5) (0.1398)
(6) Calculate mole fraction of solute in its 2 molal aqueous solution. (0.0347)
(7) Calculate the mole fractions, molality and molarity of HNO3 in a solution containing 12.2% HNO3.
Given density of HNO3 = 1.038 g cm–3, H = 1, N = 14, O = 16 ( = 0.0396 m = 2.205 mol kg–1 M = 2.01 mol dm–3)
(8) Sulphuric acid is 95.8% by mass. Calculate mole fraction and molarity of H2SO4 of density 1.91 cm3. (H = 1,S = 32, O = 16 ( = 0.80730. 17.98M).
(9) Aqueous solution of NaOH is marked 10% (w/w). The density of the solution is 1.070g cm–3. Calculate (i) molarity (ii) molality and (iii) mole fraction of NaOH and water. Na = 23. H = 10, O = 16 (M = 2.675, m = 2.77, xNaOH = 0.0476, = 0.9523)
(10) Battery acid is 4.22 M aqueous H2SO4 solution, and has density of 1.21 g cm–3. What is the molality of H2SO4? H = 1, S = 32 O = 16 (m = 5.298 mol kg–1)
