Energy of activation of a reactant is reduced by:

Options

A. Increased temperature
B. Reduced temperature
C. Reduced pressure
D. Increased pressure

Answer

To answer the question "Energy of activation of a reactant is reduced by:", we can follow these steps:

### Step 1: Understand Activation Energy
Activation energy (Ea) is the minimum energy required for a chemical reaction to occur. It is a crucial factor in determining the rate of a reaction.

**Hint:** Activation energy is a barrier that reactants must overcome for a reaction to proceed.

### Step 2: Introduce the Arrhenius Equation
The Arrhenius equation relates the rate constant (k) of a reaction to the temperature (T) and activation energy (Ea):
\[ k = A e^{-\frac{E_a}{RT}} \]
Where:
- \( k \) = rate constant
- \( A \) = pre-exponential factor (frequency factor)
- \( E_a \) = activation energy
- \( R \) = gas constant
- \( T \) = temperature in Kelvin

**Hint:** The Arrhenius equation shows how temperature and activation energy are related to the reaction rate.

### Step 3: Analyze the Effect of Temperature
From the Arrhenius equation, we can see that as the temperature (T) increases, the term \(-\frac{E_a}{RT}\) becomes less negative, which effectively increases the value of \( k \) (the rate constant). This implies that the reaction rate increases, and thus, the energy barrier (Ea) can be considered to be reduced in terms of the energy needed to reach the transition state.

**Hint:** Increasing temperature can help overcome the activation energy barrier more easily.

### Step 4: Conclude the Relationship
When temperature increases, the activation energy appears to be reduced because more molecules have enough energy to overcome the barrier. Conversely, if the temperature decreases, the activation energy effectively increases since fewer molecules can overcome the barrier.

**Hint:** Temperature has an inverse relationship with the effective activation energy in terms of reaction rate.

### Step 5: Final Answer
Therefore, the energy of activation of a reactant is reduced by increasing the temperature.

**Final Answer:** The energy of activation of a reactant is reduced by increasing the temperature.