The number of octahedral sites per sphere arranged in a face centred cubic structure, is

• 1

• 2

• 3

• 4

52.

Which one of the following has Frenkel defect?

• sodium chloride

• Graphite

• Siliver Bromide

• Diamond

50mL of benzene is mixed with 50mL of chloroform. What is the volume of solution?

• Less than 100 mL

• More than 100 mL

• Equal to 100 mL

• None of the above

For a first order reaction, velocity constant, k =10^-3 s^-1. Two third life for it would be

• 1100s

• 2200s

• 3300s

• 4400s

The reaction 2NO₂(g) + O₂(g) $\rightleftharpoons$ 2NO₂(g) is of first order. If volume of reaction vessel is reduced to 1/3, the rate of reaction would be

• 1/3 times

• 2/3 times

• 3 times

• 6 times

For the functioning of enzymes which of the following statements is not correct?

• An optimum temperature is needed

• An optimum pH is needed

• They are substrate specific

• They always increase activation energy

In the acidic solution of copper sulphate and alkaline solution of copper cyanide respectively same electric current is flown for a definite time, which of the following statement is correct for this?

• Amount of copper deposited in both the solution is the same

• Amount of copper deposited in alkaline copper cyanide solution is less

• Amount of copper deposited in acidic copper sulphate solution is less

• None of the above

What is the emf of the cell, whose half cells are given below

Mg²⁺ + 2e^- → Mg(s) E =-2.37 V

Cu²⁺ + 2e^- → Cu(s) E =+0.34 V

• -2.30V

• 1.336V

• 2.17V

• 2.93V

In chemical adsorption, how many layers are adsorbed?

• One

• Two

• Multi

• Zero

What is the role of a catalyst in a catalysed reaction?

• Lowers the activation energy

• Increases the activation energy

• Affects the free energy change

• Affects the enthalpy change