Please help me on this for my Midterm Review thank you very much...
1.For the reaction 2N2O(g) ⇋ O2(g) + 2N2(g), what happens to the equilibrium position if the pressure decreases?
A. Shift to the right
B. Shift to the left
C. Doubles
D. Does nothing
E. Halves
2.Which of the following changes will increase reaction rate?
1.An increase in the concentration of reactants
2.An increase in temperature
3.Higher-energy collisions between reacting molecules
A.1 and 2 only
B.2 and 3 only
C.1 and 3 only
D.All of 1,2, and 3
E.Neither 1,2, or 3
3.The rate of a chemical reaction is inversely proportional to the temperature.
A. True
B. False
4. A chemical equilibrium exists when:
A. The sum of reactant and product concentrations equal on mole.
B. the rate which reactants form products becomes zero.
C. Reactant are completely changed to products.
D. There are equal amounts of reactants and products.
E. The rate at which reactants form products is the same as the rate at which products form reactants.
1. To determine what happens to the equilibrium position when the pressure decreases, we can use Le Chatelier's principle. Le Chatelier's principle states that when a system at equilibrium is subjected to a change, it will adjust to counteract the change and establish a new equilibrium. In this case, when the pressure decreases, the system will try to counteract this change by favoring the side with more moles of gas.
Looking at the reaction equation, we see that the left side (2N2O) has fewer moles of gas compared to the right side (O2 + 2N2). Therefore, to increase the total number of moles of gas and regain a new equilibrium, the system will shift to the side with more moles of gas.
In this case, the right side of the reaction has a total of 3 moles of gas (1 mole of O2 and 2 moles of N2), while the left side has 2 moles of gas (2 moles of N2O). Therefore, the equilibrium position will shift to the right to increase the total moles of gas.
The correct answer is A. Shift to the right.
2. To determine which changes will increase the reaction rate, we can consider the factors that affect reaction rates.
- An increase in the concentration of reactants will lead to more frequent collisions between reacting molecules, increasing the likelihood of successful collisions and therefore increasing the reaction rate.
- An increase in temperature also increases the kinetic energy of the molecules, causing them to move faster and collide more frequently and with higher energy. This also increases the rate of the reaction.
- Higher-energy collisions between reacting molecules are more likely to lead to successful reactions, as they have enough energy to overcome the activation energy barrier.
Based on these factors, the correct answer is D. All of 1, 2, and 3 will increase the reaction rate.
3. The rate of a chemical reaction is not inversely proportional to the temperature. In fact, the rate of most chemical reactions increases with an increase in temperature. Higher temperatures provide more kinetic energy to the molecules, leading to faster collision rates and more successful collisions.
Therefore, the statement is false. The correct answer is B. False.
4. A chemical equilibrium exists when the rate at which reactants form products is equal to the rate at which products form reactants. This means that both forward and reverse reactions are occurring at the same rate, resulting in a dynamic balance.
In a chemical equilibrium, the reactants and products are present, but they do not have to be in equal amounts. The concentrations of reactants and products can vary depending on the specific equilibrium constant (K) for the reaction.
Therefore, the correct answer is E. The rate at which reactants form products is the same as the rate at which products form reactants.