Match the entries of column I with appropriate entries of column II and choose the correct option out of the four options given.

(a)-(ii), (b)-(iii), (c)-(iv), (d)-(i)

The correct answer is option 4. (a)-(ii), (b)-(iii), (c)-(iv), (d)-(i).

Let us explain each of the matches between Column I and Column II in detail:

(a) Arrhenius Equation

This is a fundamental equation in chemical kinetics that describes how the rate constant (\( k \)) of a reaction depends on temperature (\( T \)) and activation energy (\( Ea \)).

\( k = Ae^{-Ea/RT} \)

\( k \)= Rate constant

\( A \) = Pre-exponential factor (frequency factor)

\( Ea \) = Activation energy

\( R \) = Gas constant

\( T \) = Temperature in Kelvin

So, Arrhenius equation corresponds to \( k = Ae^{-Ea/RT} \). Hence, (a) - (ii).

(b) Number of Molecules Undergoing Effective Collisions Per Unit Time

This term refers to the concept in the Arrhenius equation related to the frequency factor \( A \). The frequency factor \( A \) represents the number of collisions per unit time that are sufficiently energetic and correctly oriented to lead to a reaction.

The term \( kA = e^{-Ea/RT} \) seems to describe the frequency factor in relation to the Arrhenius equation, so (b) matches with (iii).

(c) Activation Energy

This is the minimum energy required for a reaction to occur. It represents the energy barrier that reactants must overcome to form products. The activation energy itself is denoted by \( Ea \). Therefore, (c) - (iv) is correct.

(d) Threshold Energy

This term is essentially synonymous with activation energy. It represents the minimum amount of energy required for a reaction to proceed. The term \(H_p + (E_a)_b\) might be less standard, but in this context, it appears to refer to the threshold or activation energy. This might be a specific format used in some texts, but the idea is consistent with activation energy. (d) corresponds to (i), which represents the activation energy in a specific format.