31.

Maximum number of molecules of CH₃I that can react with a molecule of CH₃NH₂ are :

• 3

• 4

• 2

• 1

The t_0.5 of a radioactive isotope is 1.5 h .How long will it take for its activity to be reduced to $\frac{1}{16}$  of its original value ?

• 3.0 h

• 360 min

• 4.5 h

• 600 min

The atomic number of Ni and Cu are 28 and 29 respectively .The electronic configuration 1s , 2s² 2p⁶ , 3s² 3p⁶ 3d¹⁰ represents :

• Cu⁺

• Cu²⁺

• Ni²⁺

• Ni

An example for autocatalysis is :

• oxidation of NO to NO₂

• oxidation of SO₂ to SO₃

• decomposition of KClO₃ to KCl and O₂

• oxidation of oxalic acid by acidified KMnO₄

The highest magnetic moment is shown by the transition metal ion with the configuration :

• 3d²

• 3d⁵

• 3d⁷

• 3d⁹

A transition metal ion exists in its highest oxidation state .It is expected to behave as :

• a chelating agent

• a central metal in a coordination compound

• an oxidising agent

• a reducing agent

The concentration of a reactant X decreases from 0.1 M to 0.005 Min 40 min .If the reaction follows first order kinetics , the rate of the reaction when the concentration of X is 0.01 M will be :

• 1.73 x 10^-4 M min^-1

• 3.47 x 10^-4 M min^-1

• 3.47 x 10^-5 M min^-1

• 7.5 x 10^-4 M min^-1

Which of the following does not conduct electricity ?

• Fused NaCl

• Solid NaCl

• Brine solution

• Copper

When a quantity of electricity is passed through CusO₄ solution , 0.16 g of copper gets deposited .If the same quantity of electricity is passed through acidulated water , then the volume of H₂ liberated at STP will be :

[Given : atomic weight of Cu = 64]

• 10 cm³

• 56 cm³

• 604 cm³

• 8.0 cm³

Which one of the following condition will increase the voltage of the cell represented by the equation ?

Cu (s) + 2Ag⁺ (aq) $\rightleftharpoons$ Cu²⁺ (aq) + 2Ag (s)

• Increase in the dimension of Cu electrode

• Increase in the dimension of Ag electrode

• Increase in the concentration of Cu²⁺ ion

• Increase in the concentration of Ag⁺ ions