NY Chemistry Regents Exam Jan 2023
A process was developed in 1912 to produce ammonia gas from atmospheric nitrogen gas and hydrogen gas. Iron can be used as a catalyst. The equation representing this system at equilibrium is shown below.
72 State evidence from the equation that the forward reaction is exothermic. [1]
An Exothermic reaction releases energy. Since we see 91.8kJ on the right side, that means heat was released.
Answer: Heat (91.8KJ) is shown on the right side of the equation.
73 Compare the rate of the forward reaction to the rate of the reverse reaction at equilibrium. [1]
Answer: At equilibrium, the rate of the forward reaction is equal to the rate of the reverse reaction.
74 On the labeled axes in your answer booklet, draw a potential energy diagram for the forward reaction represented in this equation. [1]
In an exothermic reaction, the energy of products is lower than the energy of the reactants.
Answer:
75 State, in terms of moles of gases, why the equilibrium shifts to the right due to an increase in pressure on the system at constant temperature. [1]
Pressure is created by the atoms of gas. When there is an increase in pressure on the system, the equilibrium will shift to relieve this. It will shift to the side with the least moles of gas. We can add up the coefficients in the equation to get the moles on both sides.
Answer: There are 4 moles of gas on the left side and 2 moles on the right side. Therefore equibrium should shift to the right side due to an increase pressure.
76 State what happens to the rate of forward reaction when the iron is added to this system. [1]
The passages says that iron is used as a catalyst.
Catalysts speed up the rate of reaction by lowering activation energy.
Answer: Iron will increase the rate of the forward reaction.