All India Engineering / Architecture Entrance Examination (AIEEE)

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AIEEE 2008 Chemistry

Q. 23. In which of the following octahedral complexes of Co (atomic number 27), will the magnitude of be the highest?

Sol: Magnitude of will be heighest with the strongest ligand. In the given context CN^- is the strongest ligand and would lead to a greater seperatin between t_2g and c_g orbitals.

Q. 24. The coordination number and the oxidation state of the element 'E' in the complex (where (en) is ethylene diamine) are, respectively,

1. 4 and 3
2. 6 and 3
3. 6 and 2
4. 4 and 2

Sol: Ethyldiamine and oxalateion are both bidentate legends. Co-ordination number of E in the complex.

Q. 25. Identify the wrong statement in the following:

1. Ozone layer does not permit infrared radiation from the sun to reach the earth.
2. Acid rain is mostly because of oxides of nitrogen and sulphur.
3. Chlorofluorocarbons are responsible for ozone layer depletion.
4. Greenhouse effect is responsible for global warming.

Sol: Ozone layer does not permit the ultraviolet radiation from the sum to the earth.

Q. 26. Larger number of oxidation states are exhibited by the actinoids than those by lanthanoids, the main reason being

1. more energy difference between 5f and 6d than between 4f and 5d orbitals.
2. more reactive nature of the actinoids than the lanthanoids.
3. 4f orbitals more diffused than the 5f orbitals.
4. lesser energy difference between 5f and 6d than between 4f and 5d orbitals.

Sol: The energy difference between 5 f and 6d is very less than that between 4f and 5d orbitals. Therefore, in actinoids, the electron can be removed from 5f and 6d both. So, they exhibit more number of oridation state.

Q. 27. In a compound, atoms of element Y form ccp lattice and those of element X occupy 2/3^rd of tetrahedral voids. The formula of the compound will be

1. X₂Y
2. X₃Y₄
3. X₄Y₃
4. X₂Y₃

Sol:

Q. 28. Gold numbers of protective colloids (A), (B), (C) and (D) are 0.50, 0.01, 0.10 and 0.005, respectively. The correct order of their protective powers is

1. (A) < (C) < (B) < (D)
2. (B) < (D) < (A) < (C)
3. (D) < (A) < (C) < (B)
4. (C) < (B) < (D) < (A)

Sol: If the gold number of a protective coil is less then its protective power is good.

0.005 < 0.01 < 0.10 < 0.50

or, (A) < (C) < (B) < (D)

Q. 29. The vapour pressure of water at 20⁰C is 17.5 mm Hg. If 18 g of glucose (C₆H1₂O₆) is added to 178.2 g of water at 20⁰C, the vapour pressure of the resulting solution will be

1. 16.500 mm Hg
2. 17.325 mm Hg
3. 17.675 mm Hg
4. 15.750 mm Hg

Sol:

Q. 30. Bakelite is obtained from phenol by reacting with

1. CH₃COCH₃
2. HCHO
3. (CH₂OH)₂
4. CH₃CHO

Sol:

Q. 31. The absolute configuration of is

1. R, S
2. S, R
3. S, S
4. R, R

Sol: The absolute configuration is

Q. 32. For the following three reactions a, b, c, equilibrium constants are given:

a.

b.

c.

Which of the following relations is correct?

Sol:

Q. 33. Standard entropy of X2, Y2 and XY3 are 60, 40 and 50 JK^-1mol^-1, respectively. For the reaction, , to be at equilibrium, the temperature will be

1. 750 K
2. 1000 K
3. 1250 K
4. 500 K

Sol:

Q. 34. The electrophile, attacks the benzene ring to generate the intermediate complex. Of the following, which complex is of lowest energy?

Sol: complex formed by the attack of electrophile on benzene is the more stable than that formed by the attack of electrophile on nitrobenzene at any one of the three given positions.

Q. 35. Glucose are

1. anomers
2. enantiomers
3. conformers
4. epimers

Sol: