Consider the reaction A ⇌ B which is exothermic in the forward direction. Which of the following increase(s) when the temperature increases.
the reverse rate
a. the reverse rate
b. the forward rate
c. Ea (reverse)
d. Ea (forward)
I go with b
When the temperature increases for an exothermic reaction in the forward direction, the following factors increase:
b. The forward rate: As the temperature increases, the particles have more energy and collide with each other more frequently and with greater energy. This leads to an increase in the rate of the forward reaction.
c. Ea (reverse): Ea (reverse) refers to the activation energy for the reverse reaction. When the temperature increases, the average kinetic energy of the particles also increases, making it easier for the particles to overcome the activation energy barrier and undergo the reverse reaction.
d. Ea (forward): Ea (forward) refers to the activation energy for the forward reaction. However, with an increase in temperature, the average kinetic energy of the particles also increases, which makes it easier for them to overcome the activation energy barrier of the forward reaction, thus decreasing the activation energy.
Therefore, the correct answer is:
b. The forward rate
c. Ea (reverse)
To determine which of the options increase when the temperature increases in an exothermic reaction A ⇌ B, we need to consider the effect of temperature on the rates of the forward and reverse reactions.
When the temperature increases, the kinetic energy of the reactant molecules also increases. This leads to more frequent collisions between the reactant molecules, resulting in an increase in the rate of reaction.
In an exothermic reaction, the forward reaction is the exothermic reaction, meaning it releases energy. The reverse reaction, on the other hand, is the endothermic reaction, absorbing energy.
Based on this information, we can conclude that:
a. The reverse rate: When the temperature increases, the reverse rate of the reaction will decrease. This is because the increase in temperature will enhance the forward reaction rate (which is exothermic) more than the reverse reaction rate.
b. The forward rate: When the temperature increases, the forward rate of the reaction will increase. This is because the increase in temperature provides more kinetic energy to the reactant molecules, leading to more effective collisions and a faster forward reaction rate.
c. Ea(reverse): The activation energy for the reverse reaction will remain the same. The activation energy is a property of the reaction itself and is not affected directly by temperature changes.
d. Ea(forward): The activation energy for the forward reaction will remain the same. Similar to the reverse reaction, the activation energy for the forward reaction is a property of the reaction and remains constant regardless of temperature changes.
Therefore, the correct answer is:
b. The forward rate (increases when the temperature increases)