Question

In a chemical reaction 4mol of Nitrogen monoxide NO and 2.5mol of oxygen O2 are mixed together in a container with a volume of 1000ml to produce Nitrogen Dioxide NO2. If equilibrium constant Kc for this reaction is 0.001.

1. Write a balanced chemical equation for the above reaction?

2. Determine the equilibrium concentrations for each substance?

3. If the overall enthalpy of the above reaction is 49kJ/mol. Predict the outcome of the reaction?

4. If the volume of the product NO2, is being increased, where will equilibrium shift to and why will it have to shift that way?

5. What is happen to the equilibrium constant Kc value if temperature is increased?

Answer 1

[AI-generated answer — Bot GPT 3.5]

1. Balanced chemical equation:

2NO(g) + O2(g) -> 2NO2(g)

2. Let x be the change in concentration for NO2 at equilibrium, then the concentrations for each substance will be:
[NO] = 4 - 2x mol/L
[O2] = 2.5 - x mol/L
[NO2] = x mol/L

From the equilibrium constant expression:
Kc = [NO2]^2 / ([NO]*[O2])
0.001 = x^2 / ((4-2x)*(2.5-x))

Solving this equation will give the equilibrium concentration for each substance.

3. Since the overall enthalpy of the reaction is positive (endothermic), the reaction will shift to the right in order to consume some of the added heat.

4. If the volume of the product NO2 is being increased, the equilibrium will shift to the left to produce more NO and O2 in order to compensate for the increase in volume of the product.

5. If the temperature is increased, the equilibrium constant Kc value will also increase. This is because the equilibrium constant is temperature-dependent, and increasing the temperature will favor the endothermic reaction, shifting the equilibrium towards the products.