All India Engineering / Architecture Entrance Examination (AIEEE)

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AIEEE 2007 Chemistry

Q. 4. Consider the reaction, When concentration of B alone was doubled, the half−life did not change. When the concentration of A alone was doubled, the rate increased by two times. The unit of rate constant for this reaction is

1. 
2. no unit
3. 
4. 

Sol: The reaction would be first order with respect to A and first order with respect to B. The overall order of the reaction is 2.

Correct choice: (1)

Q. 5.. Identify the incorrect statement among the following:

1. d−Block elements show irregular and erratic chemical properties among themselves .
2. La and Lu have partially filled d orbitals and no other partially filled orbitals.
3. The chemistry of various lanthanoids is very similar.
4. 4f and 5f orbitals are equally shielded.

Sol: 4f orbital electrons are shielded more than 5f orbital electrons.
Correct choice: (4)

Q. 6. Which one of the following has a square planar geometry?

(Atomic numbers: Co = 27, Ni = 28, Fe = 26, Pt = 78)
Sol: Platinum(+II) only forms square planar complex. Correct choice: (4)

Q. 7. Which of the following molecules is expected to rotate the plane of plane − polarised light?

Sol: Compound (1) does not have any plane of symmetry as well as centre of symmetry so it rotates the plane of plane−polarised light. Compound (2), (3) and (4) have a plane of symmetry, so they all are optically inactive.
Correct choice: (1)