Question 1: Define a reversible reaction in the context of chemical processes.

Answer: A reversible reaction is a chemical process where the reactants can form products, which can then react to regenerate the original reactants, reaching a state of dynamic equilibrium.

Question 2: Explain how Le Châtelier’s Principle applies to reversible reactions in industrial engineering.

Answer: Le Châtelier’s Principle states that if a system at equilibrium experiences a change in concentration, temperature, or pressure, the system shifts to minimise the effect of that change, thereby adjusting the position of equilibrium to maintain balance.

Question 3: Describe the mechanism by which a reversible reaction reaches equilibrium.

Answer: A reversible reaction reaches equilibrium when the rate of the forward reaction equals the rate of the reverse reaction, resulting in no net change in the concentrations of reactants and products.

Question 1: In a reversible reaction, the forward reaction rate is 0.8 mol/s and the reverse reaction rate is 0.8 mol/s at equilibrium. Calculate the net rate of reaction.

Answer: 0 mol/s (since forward rate equals reverse rate, net rate is zero).

Question 2: A reversible reaction has an equilibrium constant (Kc) of 4.0 at a certain temperature. If the concentration of reactant A is 2 mol/L, what is the concentration of product B, assuming a simple reaction A ⇌ B?

Answer: Concentration of B = 8 mol/L (assuming Kc = [B]/[A], so [B] = Kc × [A] = 4.0 × 2 = 8 mol/L).

Question 1: Describe a theoretical experiment to investigate how temperature affects the position of equilibrium in a reversible reaction used in industry.

Answer: The experiment would involve setting up a reversible reaction system in a controlled environment, varying the temperature in different trials while keeping concentration and pressure constant. The equilibrium position would be assessed by measuring reactant and product concentrations at each temperature, ensuring safety protocols such as proper ventilation and protective equipment are in place due to possible release of hazardous gases.

Question 2: Identify two variables that must be controlled to accurately study the effect of pressure on a reversible gaseous reaction in industry.

Answer: Temperature and reactant concentrations.

Question 1: A reversible reaction in a chemical plant shows that increasing pressure shifts the equilibrium towards fewer moles of gas. Explain how this principle is applied to optimise industrial production.

Answer: By increasing pressure, the system shifts toward the side with fewer moles of gas, thereby increasing yield and efficiency in industrial processes such as synthesis of ammonia, reducing waste and energy consumption.

Question 2: An engineer notes that a reversible reaction used in manufacturing has a slow forward and reverse rate at a certain temperature. What adjustments could optimise the reaction rate without disturbing the equilibrium?

Answer: Increasing the temperature or adding a catalyst could speed up both the forward and reverse reactions, improving overall reaction rate without changing the equilibrium position.

Question 1: Explain how reversible reactions are utilised in the Haber process for ammonia synthesis, including the significance of equilibrium and how conditions are manipulated to maximise yield.

Answer: In the Haber process, nitrogen and hydrogen gases react reversibly to produce ammonia. The system reaches equilibrium where forward and reverse reaction rates are equal. To maximise ammonia yield, conditions such as high pressure, moderate temperature, and catalysts are used. High pressure shifts the equilibrium towards ammonia, while temperature is balanced to ensure a reasonable rate and yield. Understanding the reversible nature of the reaction allows engineers to optimise conditions, ensuring economic efficiency and sustainable production.