Question

Using this reversible reaction, answer the following:

N2O4 <--> 2NO2
(colorless) (reddish-brown)

-As the temperature increased, what happened to the [N2O4]?

-Was the formation of reactants or products favored by the addition of heat?

-Which reaction is exothermic?

-If the change of enthalpy of this reaction when proceeding left to right is 14 kcal, which chemical equation is correct?


N2O4 <--> 2NO2 + 14 kcal
N2O4 <--> 2NO2, HR = +14 kcal
N2O4 + 14 kcal <--> 2NO2
N2O4 <--> 2NO2, HR = -14 kcal

Answer 1

-Products formed by the forward
reaction may react with each other to regenerate the reactants.
-When reactants are mixed, they will begin to react at a forward reaction rate particular to that chemical reaction.
- As reactants are depleted and products are formed, however, the rate of the forward reaction begins to slow, and the rate of the reverse reaction begins to increase.

Answer 2

Question 1.

Answer:

The concentration of [N2O4] will decrease.

Step-by-step explanation:

• As the reverse reaction which is the formation of N2O4 is an exothermic reaction and the formation of NO2 is an endothermic reaction.
• Hence heating will favor the forward reaction and stops the reverse reaction.
• N2O4 --> 2NO2
• So the concentration of N2O4 decreases.

Question: 2.

Answer:

The formation of the products is favored by the addition of heat.

Step-by-step explanation:

• As the reverse reaction which is the formation of N2O4 is an exothermic reaction and the formation of NO2 is an endothermic reaction.
• So the addition of heat will favor endothermic reaction.
• Hence the formation of NO2 will be favored which is a product.

Question no.4:

Answer:

The reverse reaction is an exothermic reaction.

N2O4 <-- 2NO2.

Step-by-step explanation:

• N2O4 which is a reactant in this reaction is colorless compound.
• Its breakdown absorbs energy and its formation release energy in form of heat.
• So the reverse reaction which releases energy is an exothermic reaction.

Question no. 4

Answer:

The correct option is D which is N2O4 <--> 2NO2, HR = -14 kcal.

Step-by-step explanation:

• Enthalpy is the change in energy in reactants and products.
• It is actually the difference in energies of products and reactant.
• As the enthalpy change from left to right, it means reactants have internal energy 14 kcal high than products and it will be released.
• And in option D which is shown as HR = -14 kcal.