Questions -- give ans

11. The largest number of molecules is present in 1 g of

(a) CO₂    (b) H₂O    (c) C₂H₅OH     (d) N₂O₅

12. The non-nucleophilic base is

(a) CN ^–     (b) ^– OC (Me)₃   (c) ^– OH   (d) MeO ^–

13. A soap solution in water removes greasy substances by

(a) adsorption        (b) peptization     (c) coagulation      (d) emulsification

14. A gas will approach ideal behaviour at

(a) low temperature and low pressure

(b) low temperature and high pressure

(c) high temperature and low pressure

(d) high temperature and high pressure

15. The compound that has the highest dipole moment is

(a) cis-1,2-dichloroethene

(b) trans-1,2-dichloroethene

(c) cis-1-chloro-2-bromoethene

(d) -1-chloro-2-bromoethene

16. A firework gives out crimson coloured light, due to the presence of salts of

(a) calcium     (b) sodium    (c) barium     (d) strontium

17. The fuel that is considered least polluting is

(a) petrol      (b) coke      (c) furnace oil      (d) CNG

18. A certain current passed through a CuSO₄ solution for 100 seconds deposits 0.3175 g of Copper. The current passed (in A) is

(a) 4.83       (b) 9.65       (c) 0.965       (d) 0.483

19. The most stable carbocation is

                         +

(a)    CH₃-S-CH₂

                               +

(b)   CH₃-CH-CH₂

                +

(c)    F-CH₂

                 +

(d)   Cl₃C

20. CCl₄ (g) + 2H₂O (g) → CO₂(g) + 4HCl (g)

The standard enthalpies of formation at 298 K for CCl₄ (g), 2H₂O (g), CO₂(g) and HCl(g) are -106.7, -241.8, -393.7, and -92.5 kJmol^-1 respectively. The value of ΔH^o₂₉₈ for the above reaction is

(a) -137.7 kJ       (b) 173.4 kJ       (c) -173.4 kJ       (d) 137.7 kJ