Question

multiple choice: write the letter of the correct choice in the blank.

1. which of the following statements describes the relative concentration of reactants and products at equilibrium?

a. no reactants are present.
b. no products are present.
c. reactants and products are present in equal amounts.
d. relative concentrations depend on the reaction.

1. how would an increase in pressure affect the equilibrium of the reaction co₂(g) + h₂o(l) ⇌ h₂co₃(aq)?

a. equilibrium shifts left
c. no effect on equilibrium
b. equilibrium shifts right
d. reaction goes to completion

1. how would addition of a catalyst affect the equilibrium of the reaction co₂(g) + h₂o(l) ⇌ h₂co₃(aq)?

a. equilibrium shifts left
c. no effect on equilibrium
b. equilibrium shifts right
d. reaction goes to completion

1. how would continually removing the products affect an equilibrium system?

a. equilibrium shifts left
c. no effect on equilibrium
b. equilibrium shifts right
d. reaction goes to completion

1. how would an increase in pressure affect the equilibrium of the reaction so₃(g) + h₂(g) ⇌ so₂(g) + h₂o(g)?

a. equilibrium shifts left
c. no effect on equilibrium
b. equilibrium shifts right
d. reaction goes to completion

Explanation:

• Question 4: Chemical equilibrium is a dynamic state where the concentrations of reactants and products remain constant, but their relative concentrations depend on the specific reaction. Options a and b are incorrect because in equilibrium, both reactants and products are present. Option c is incorrect as equal amounts are not a general rule.
• Question 5: According to Le Chatelier's principle, increasing pressure shifts the equilibrium towards the side with fewer moles of gas. In the reaction \(CO_2(g)+H_2O(l)

ightleftharpoons H_2CO_3(aq)\), the right - hand side has no gas (or fewer moles of gas if we consider the liquid as having negligible gas - like behavior in terms of pressure effects on equilibrium for this simple analysis). So, increasing pressure shifts the equilibrium to the right.

• Question 6: A catalyst speeds up the forward and reverse reactions equally. It does not change the position of the equilibrium.
• Question 7: Removing products (a stress) causes the equilibrium to shift to the right (to produce more products) according to Le Chatelier's principle.
• Question 8: In the reaction \(SO_3(g)+H_2(g)

ightleftharpoons SO_2(g)+H_2O(g)\), the number of moles of gas on the left - hand side (\(n_{left}=1 + 1=2\)) is equal to the number of moles of gas on the right - hand side (\(n_{right}=1+1 = 2\)). According to Le Chatelier's principle, a change in pressure (when the number of moles of gas on both sides is equal) has no effect on the equilibrium.

Answer:

1. d. Relative concentrations depend on the reaction.
2. b. equilibrium shifts right
3. c. no effect on equilibrium
4. b. equilibrium shifts right
5. c. no effect on equilibrium