Which of the following experimental conditions describe a reaction which is kinetically controlled?

These conditions do not describe kinetic control.

ΔG = -100 kJ/molrxn; there is no observable reaction when reactants are mixed.

ΔG = +100 kJ/molrxn; there is no observable reaction when reactants are mixed.

ΔG = +100 kJ/molrxn; the reaction proceeds rapidly when reactants are mixed.

ΔG = -100 kJ/molrxn; the reaction proceeds rapidly when reactants are mixed.

I know it's not these two.

ΔG = +100 kJ/molrxn; the reaction proceeds rapidly when reactants are mixed.



ΔG = -100 kJ/molrxn; the reaction proceeds rapidly when reactants are mixed.

The condition that describes a reaction which is kinetically controlled is:

ΔG = -100 kJ/molrxn; the reaction proceeds rapidly when reactants are mixed.

To determine which of the given experimental conditions describe a reaction that is kinetically controlled, we need to understand the concept of kinetic control in reactions.

Kinetic control refers to a situation where the rate of a reaction is determined primarily by the activation energy, rather than the thermodynamic stability of the products. In other words, the reaction proceeds rapidly, regardless of the thermodynamic favorability.

Now, let's analyze each condition:

1. ΔG = -100 kJ/molrxn; there is no observable reaction when reactants are mixed.
This condition does not describe kinetic control, as there is no observable reaction. This suggests that the activation energy barrier for the reaction to occur is too high to be overcome, regardless of the thermodynamic favorability.

2. ΔG = +100 kJ/molrxn; there is no observable reaction when reactants are mixed.
Similar to the previous condition, this also does not describe kinetic control. The positive value of ΔG suggests that the reaction is not thermodynamically favorable, and the lack of observable reaction confirms a high activation energy barrier.

3. ΔG = +100 kJ/molrxn; the reaction proceeds rapidly when reactants are mixed.
This condition describes kinetic control. Despite the unfavorable thermodynamics (positive ΔG), the reaction proceeds rapidly, suggesting that the activation energy barrier is low enough for the reaction to occur.

4. ΔG = -100 kJ/molrxn; the reaction proceeds rapidly when reactants are mixed.
This condition also describes kinetic control. Here, the reaction is both thermodynamically favorable (negative ΔG) and proceeds rapidly, indicating a low activation energy barrier.

Therefore, the correct answer is conditions number 3 and 4: ΔG = +100 kJ/molrxn; the reaction proceeds rapidly when reactants are mixed and ΔG = -100 kJ/molrxn; the reaction proceeds rapidly when reactants are mixed.