3c-Reversible reactions and equilibria

Question 1

Question: What is a reversible reaction?

Answer 1

Answer: A reversible reaction is a chemical reaction where the products can react to reform the reactants.

Question 2

Question: What is equilibrium in a reversible reaction?

Answer 2

Answer: Equilibrium is the state in a closed system where the forward and backward reactions occur at the same rate, and the concentrations of reactants and products remain constant.

Question 3

Question: What is meant by a closed system?

Answer 3

Answer: A closed system is one where no substances can enter or leave, allowing equilibrium to be established.

Question 4

Question: What is Le Chatelier’s Principle?

Answer 4

Answer: Le Chatelier’s Principle states that if a system at equilibrium is subjected to a change in conditions, the system will adjust to counteract the change.

Question 5

Question: How does changing concentration affect equilibrium?

Answer 5

Answer:

Increasing the concentration of reactants shifts equilibrium to the right, producing more products.

Increasing the concentration of products shifts equilibrium to the left, producing more reactants

Question 6

Question: How does changing pressure affect equilibrium? (For gases)Answer:

Answer 6

Increasing pressure shifts equilibrium toward the side with fewer gas molecules.

Decreasing pressure shifts equilibrium toward the side with more gas molecules.

Question 7

Question: How does changing temperature affect equilibrium?Answer:

Answer 7

Increasing temperature shifts equilibrium in the endothermic direction.

Decreasing temperature shifts equilibrium in the exothermic direction.

Question 8

Question: What is the effect of a catalyst on equilibrium?

Answer 8

Answer: A catalyst speeds up both the forward and backward reactions equally, without shifting the equilibrium position.

Question 9

Question: Give an example of a reversible reaction

Answer 9

.Answer:

The reaction between ammonium chloride and ammonia:NH₄Cl (s) ⇌ NH₃ (g) + HCl (g)

Question 10

Question: How is equilibrium important in industry?

Answer 10

Answer: In processes like the Haber process, controlling temperature and pressure ensures the maximum yield of products.

Question 11

Practical: Investigating a Reversible Reaction (Hydrated Copper Sulfate)

Method:

Answer 11

Heat blue hydrated copper sulfate (CuSO₄·5H₂O) until it turns white (anhydrous copper sulfate).

Add water to the white powder, observing the blue color return.

Question 12

Practical: Investigating a Reversible Reaction (Hydrated Copper Sulfate)

Results & conclusion

Answer 12

Results:

Heating removes water, making the reaction endothermic.

Adding water is exothermic, showing reversibility.

Conclusion:

The color change demonstrates a reversible reaction.