Question

Question 12(Multiple Choice Worth 1 points) (07.01 LC) Which of the following is a characteristic of an endothermic chemical reaction? The energy of the reactants is higher than the energy of the products. The amount of energy released is equal to the activation energy. The overall enthalpy of the system increases during the change. Energy is released into the surroundings during this change. Question 13(Multiple Choice Worth 1 points) (07.05 MC) The volume of a reaction vessel with gaseous reactants is lowered to one-fourth of its original volume. What will happen to the rate of the reaction? It will increase because the concentration of the reactants increases. It will decrease because the concentration of the reactants decreases. It will increase because the gaseous particles are moved farther apart. It will decrease because the gaseous particles are brought closer together. Question 14(Multiple Choice Worth 1 points) (07.06 MC) The equilibrium constant K for a certain reversible reaction is 1.41 × 103. Which of the following is true for the reaction? The reverse reaction is more favorable than the forward reaction. The reverse reaction takes place at a much faster rate than the forward reaction. The equilibrium reaction mixture will have a very high concentration of reactants. The equilibrium reaction mixture will have a very high concentration of products. Question 15(Multiple Choice Worth 1 points) (07.07 MC) A reaction mixture is at equilibrium. What happens when the amount of one of the reactants is lowered? The amount of the product increases. The rate of reverse reaction increases. The amount of the other reactant is also lowered. The equilibrium state is lost and cannot be restored.

Answer 1

12)

Answer: an endothermic reaction is where there is absorption of energy during the reaction. The energy of reactants is less than the energy of products.

As the enthalpy of the reaction is the difference in the total enthalpy of formation of products and total energy of formation of reactants and in endothermic reaction enthalpy is positive.

thus the energy of products is more than the energy of reactants.

The true statement is :The overall enthalpy of the system increases during the change.

Question 13

If the volume is lowered to one fourth it will increase the concentration (moles/volume). Thus, It will increase because the concentration of the reactants increases.

Question 14

As the value of equilibrium constant is in multiple of thousand, the reaction will be more favourable in forward direction hence

Ans:  The equilibrium reaction mixture will have a very high concentration of products.

Question 15

As the system is in equilibrium and by decreasing the concentration of reactant we are disturbing the equilibrium state. In order to maintain the equlibrium the system will move in backward direction and hence

The rate of reverse reaction increases.