Question

muruple choice must be on scantron MOLTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Which reaction will shift to the left in response to a decrease in volume? A) 2 SO3 (8) 2 SO2 (8) + O2 (8) B) N2 (8) + 3H2 (8) 2 NH3 (8) C) 2HI (8) H2(g) + 12 (g) D) 4 Fe (s) + 3 O2 (g) 2 Fe203 (s) E) H2 (8) + Cl2 (8) 2 HCl (8) Explain 2) Based on Le Châtelier's principle, increasing pressure at constant temperature in the following reaction will not change the concentrations of reactants and products. A) N2 (8) +202 (8) 2NO2 (8) B) N2(g) + O2(g) 2NO(g) C) 2N2 (g) + O2(g) 2N20 (8) D) N204 (8) 2NO2 (g) E) N2 (8) + 3H2 (8) 2NH3 (8) Explain

Answer 1

1)

The reaction

A) 2 SO₃ (g) $\rightleftharpoons$ 2 SO₂ (g) + O₂ (g) shifts left in response to decrease in volume

number of moles of the reactants in the equation = 2

number of moles of the products in the equation = 2 + 1 = 3

At a given temperature and pressure one mole of any gas occupies the same amount of volume.Since the number of moles of reactants are less than the number of moles of reactants in the equation we can see that the volume increases during forward reaction.Therefore the increase in the volume favours forward reaction or equilibrium shifts towards right whereas decrease in volume favours the backward reaction or shifts equilibrium towards left.

If the number of moles in the reactant side are more than the number of moles of on the product side then decrease in volume favours the forward reaction and vice versa.

If the number of moles in the reactant side are more than the number of moles of on the product side then increase in volume favours the backward reaction and vice versa

2)

The reaction

B) N₂ (g) + O₂ (g) $\rightleftharpoons$ 2 NO (g) will not be affected by the change in the volume.

If pressure is increased on a system it decreases the volume of the system.It was already explained above how change in volume affects the reaction.Since the pressure and volume are inversely proportional.The effect of change in pressure on the system will be reverse of that of change in volume of the system.

In the above reaction number of moles of reactants = number of moles of products

therefore there is no change in volume during the course of reaction.Therefore change in volume has no effect on the concentration of reactants and products.since the change in pressure affects the reaction by changing the volume the change in pressure has no effect on the reaction