Explain the significance of the exponential factor e -Ea/RT in the Arrhenius equation.

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### Question 10

**Explain the significance of the exponential factor \( e^{-E_a/RT} \) in the Arrhenius equation.**

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**Detailed Explanation:**

The exponential factor \( e^{-E_a/RT} \) in the Arrhenius equation is crucial in understanding how the rate of a chemical reaction depends on temperature and activation energy. Here's what each term represents:

- **\( E_a \)**: The activation energy of the reaction, which is the minimum energy that reactant molecules must possess in order for a reaction to occur.
- **\( R \)**: The universal gas constant, which has a value of approximately 8.314 J/(mol·K).
- **\( T \)**: The absolute temperature in Kelvin.

The exponential factor \( e^{-E_a/RT} \) essentially determines the fraction of molecules that have enough energy to surpass the energy barrier (activation energy, \( E_a \)) at a given temperature.

- When \( T \) increases, the term \( \frac{E_a}{RT} \) decreases, thus making \( e^{-E_a/RT} \) larger. This means that more molecules have sufficient energy to react, therefore the reaction rate increases.
- Conversely, if \( T \) is lower, \( \frac{E_a}{RT} \) increases, making \( e^{-E_a/RT} \) smaller. This results in fewer molecules having the needed energy to react, thus decreasing the reaction rate.

In summary, \( e^{-E_a/RT} \) quantifies the effect of temperature and activation energy on the reaction rate, helping to explain why higher temperatures typically increase reaction rates by providing more energy to the reacting molecules.
Transcribed Image Text:### Question 10 **Explain the significance of the exponential factor \( e^{-E_a/RT} \) in the Arrhenius equation.** --- **Detailed Explanation:** The exponential factor \( e^{-E_a/RT} \) in the Arrhenius equation is crucial in understanding how the rate of a chemical reaction depends on temperature and activation energy. Here's what each term represents: - **\( E_a \)**: The activation energy of the reaction, which is the minimum energy that reactant molecules must possess in order for a reaction to occur. - **\( R \)**: The universal gas constant, which has a value of approximately 8.314 J/(mol·K). - **\( T \)**: The absolute temperature in Kelvin. The exponential factor \( e^{-E_a/RT} \) essentially determines the fraction of molecules that have enough energy to surpass the energy barrier (activation energy, \( E_a \)) at a given temperature. - When \( T \) increases, the term \( \frac{E_a}{RT} \) decreases, thus making \( e^{-E_a/RT} \) larger. This means that more molecules have sufficient energy to react, therefore the reaction rate increases. - Conversely, if \( T \) is lower, \( \frac{E_a}{RT} \) increases, making \( e^{-E_a/RT} \) smaller. This results in fewer molecules having the needed energy to react, thus decreasing the reaction rate. In summary, \( e^{-E_a/RT} \) quantifies the effect of temperature and activation energy on the reaction rate, helping to explain why higher temperatures typically increase reaction rates by providing more energy to the reacting molecules.
**Question 7**

**Based on the following energy diagram, which compound, A or C, is formed faster from B? Which is more stable, A or C? Explain.**

*Energy Diagram Description*:

The energy diagram presented shows the energy (denoted as E on the y-axis) versus the reaction coordinate (x-axis). The diagram includes three points: A, B, and C. Here is a detailed description:

1. **Point A** is shown at the left side of the diagram, positioned at a lower energy level.
2. From A, the energy increases to a peak, and then decreases slightly to reach point B.
3. There is another increase in energy from B to another peak, followed by a steeper energy decrease to reach point C on the right side of the diagram, positioned at a lower energy level than B but higher than A.

*Explanation for the Questions*:

1. **Which compound, A or C, is formed faster from B?**
   To determine which compound (A or C) is formed faster from B, we need to consider the energy barriers between B and A, and B and C. A higher energy peak indicates a higher activation energy, which corresponds to slower reaction kinetics.
   - From the diagram, the energy barrier between B and A is lower than the energy barrier between B and C. This implies that the transition from B to A has a lower activation energy compared to B to C.
   - Therefore, compound A is formed faster from B.

2. **Which is more stable, A or C?**
   To determine which compound is more stable, we compare their energies. The more stable compound will be the one with the lower energy in the energy diagram.
   - Point A is at a lower energy level compared to point C.
   - Therefore, compound A is more stable than compound C.

In summary:
- **Compound A** is formed faster from B.
- **Compound A** is also more stable than compound C.
Transcribed Image Text:**Question 7** **Based on the following energy diagram, which compound, A or C, is formed faster from B? Which is more stable, A or C? Explain.** *Energy Diagram Description*: The energy diagram presented shows the energy (denoted as E on the y-axis) versus the reaction coordinate (x-axis). The diagram includes three points: A, B, and C. Here is a detailed description: 1. **Point A** is shown at the left side of the diagram, positioned at a lower energy level. 2. From A, the energy increases to a peak, and then decreases slightly to reach point B. 3. There is another increase in energy from B to another peak, followed by a steeper energy decrease to reach point C on the right side of the diagram, positioned at a lower energy level than B but higher than A. *Explanation for the Questions*: 1. **Which compound, A or C, is formed faster from B?** To determine which compound (A or C) is formed faster from B, we need to consider the energy barriers between B and A, and B and C. A higher energy peak indicates a higher activation energy, which corresponds to slower reaction kinetics. - From the diagram, the energy barrier between B and A is lower than the energy barrier between B and C. This implies that the transition from B to A has a lower activation energy compared to B to C. - Therefore, compound A is formed faster from B. 2. **Which is more stable, A or C?** To determine which compound is more stable, we compare their energies. The more stable compound will be the one with the lower energy in the energy diagram. - Point A is at a lower energy level compared to point C. - Therefore, compound A is more stable than compound C. In summary: - **Compound A** is formed faster from B. - **Compound A** is also more stable than compound C.
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