Question

14. If the molar mass of toluene is 925 gmol, how much toluene is needed to depress the freezing point of 200 g of benzene by 0.47°C? K 5 .12"C/m A 1.79 B. 179 C.0.0.919 D. 18.359 E. Not enough information given to answer 15. For crystal lattice where dimension, a b=cand also all angles a Bay = 90° represents: B. cubic A tetragonal tetragonal D. orthorhombic E both A and C 16. Consider the compounds water (HO). dimethylether (CH,OCH), ethanol (CH.CH,OH), and propane (CHCH2CH). Their boiling points, not necessarily in order, are -42.1 °C -24.8 C, 78.4 °C and 100'C. Which one is INCORRECT prediction: A. water [100°C] B. ethanol [78.4 °C] C. propane (-24.7°C] D. dimethylether [-24.7°C] E. propane (-421 °C] LLC 17. If the solute concentration outside the cell is less than that inside the cell, the solution is A isotonic B. hypertonic C. hypotonic D. both B and C 18. The red blood cells (RBCs) will result in hemolysis, if we place the cells in solution. A isotonic B. hypertonic C. hypotonic D. both B and C 19: Which of the following is not a colloidal system? A. aerosol spray B. cream foam © C. floating soap D.pure water 20. Highest limiting value of vant Hoff factor is among following: r B. Naci r A. Urea r C.MgSo. CDK SO

Answer 1

AT = 14. Atq=&ym i=1 zoe hydrocarbon 0.47 = 4 x 5.12 moles of solute mass of solvent (kg) 0.47 = 1 x 5.12 x mass of toulene molar mass of toluene X . mass of benzene 0.47 = 2 x 5.12 X mass of toluene 92.6 glmol x 0.2kg mass of toewine = 1.7 g 15. a = b = c a=p=8 = 90°c - (B) Cubic