Question

The following questions, Q.No 17 – 25 are short answer type and carry 2 marks each.

17. The vapour pressure of 2.1 % of an aqueous solution of a non-electrolyte at 373K is 755 mm. Calculate

the molar mass of solute? Given V.P of pure solvent=760 mm of Hg

18. The treatment of alkyl chlorides with aqueous KOH leads to the formation of alcohol but when it treated

with the alcoholic KOH alkene is the major product. Explain why?

19. How do you explain the absence of aldehyde group in the pentaacetate of D-Glucose?

20. Resistance of a conductivity cell filled with 0.1 mol L–1 KCl solution is 100 Ω. If the resistance of the

same cell when filled with 0.02 mol L–1 KCl solution is 520 Ω, calculate the conductivity and molar

conductivity of 0.02 mol L–1 KCl solution. The conductivity of 0.1 mol L–1 KCl solution is 1.29 S/m.

21. Calculate the value of Avogadro’s no. of KF (FCC) having density 2.48g/cm3 and distance between K+

and F- is 269pm. KF (At mass K=39, F=19)

22. Give reason: the d4 species, Cr2+ is strongly reducing while manganese (III) is strongly oxidising.

23. Complete the following equation:

NaOH + Cl2

(Hot & conc)

24. For a reaction, A + B → Product; the rate law is given by, r = k [ A]1/2 [B]2.

a) How is the rate affected on increasing the concentration of B three times?

b) How is the rate affected when the concentrations of both A and B are doubled?

25. Write the formulas for the following coordination compounds:

a) Dichloridobis(ethane–1,2–diamine)platinum(IV) nitrate

b) Iron(III) hexacyanoferrate(II)

​

Answer 1

It is an important chemical reagent and industrial chemical, used primarily in the production of cellulose acetate for photographic film, polyvinyl acetate for wood glue, and synthetic fibres and fabrics. In households, diluted acetic acid is often used in descaling agents.