All India Engineering / Architecture Entrance Examination (AIEEE)

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AIEEE 2008 Chemistry

Q. 13. Phenol, when it first reacts with concentrated sulphuric acid and then with concentrated nitric acid, gives

1. p-nitrophenol
2. nitrobenzene
3. 2,4,6-trinitrobenzene
4. o-nitrophenol

Sol:

As, temperature is not mentioned, 0- mitrophenol is the only stable product.

Q. 14. The ionization enthalpy of hydrogen atom is 1.312 × 10⁶ J mol^-1. The energy required to excite the electron in the atom from n = 1 to n = 2 is

Sol:

Q. 15. The organic chloro compound, which shows complete stereochemical inversion during a S_N2 reaction, is

1. (CH₃)₂CHCl
2. CH₃Cl
3. (C₂H₅)₂CHCl
4. (CH₃)₃CCl

Sol: Primary halides show inversion during S_N2 reaction more than secondary while secondary show more than tertiary.

Q. 16. Toluene is nitrated and the resulting product is reduced with tin and hydrochloric acid. The product so obtained is diazotized and then heated with cuprous bromide. The reaction mixture so formed contains

1. mixture of o-; and p-bromoanilines
2. mixture of o- and m-bromotoluenes
3. mixture of o- and p-bromotoluenes
4. mixture of o- and p-dibromobenzenes

Sol:

Q. 17. In the following sequence of reactions, the alkene affords the compound 'B'

The compound B is

1. CH₃CH₂COCH₃
2. CH₃CHO
3. CH₃CH₂CHO
4. CH₃COCH₃

Sol:

Correct answer is (2)

Q. 18. Which one of the following pairs of species have the same bond order?

Sol: The species which have the same number of total electrons will have the same bond order.
CN^- and NO⁺ each have 14 electrons and they will have same bond order.

Q. 19. At 80⁰C, the vapour pressure of pure liquid 'A' is 520 mm Hg and that of pure liquid 'B' is 1000 mm Hg. If a mixture solution of 'A' and 'B' boils at 80⁰C and 1 atm pressure, the amount of 'A' in the mixture is (1 atm = 760 mm Hg)

1. 48 mol percent
2. 50 mol percent
3. 52 mol percent
4. 34 mol percent

Sol:

Q. 20. For a reaction , rate of disappearance of 'A' is related to the rate of appearance of 'B' by the expression

Sol:

Q. 21. The equilibrium constants for the reactions respectively are in the ratio of 1 : 9. If the degree of dissociation of X and Z be equal then the ratio of total pressures at these equilibria is

1. 1 : 3
2. 1 : 9
3. 1 : 36
4. 1 : 1

Sol:

Q. 22. In context with the industrial preparation of hydrogen from water gas (CO + H₂), which of the following is the correct statement?

1. H₂ is removed through occlusion with Pd.
2. CO is oxidised to CO₂ with steam in the presence of a catalyst followed by absorption of CO₂in alkali.
3. CO and H₂are fractionally separated using differences in their densities.
4. CO is removed by absorption in aqueous Cu₂Cl₂solution.

Sol: