Question

EXPERIMENT 8 Post-Lab Questions Name: Leiseu Scalish Section: 1. Consider the following system at equilibrium in a closed container (pressure at 1 atm): NaOH(s) + CO2(g) + NaHCO3(s) AHºrn < 0 Concentration of CO2 gas present at equilibrium can be decreased by True or False (T or F) adding N2 gas to double the pressure adding more NaOH increasing the volume of the container lowering the temperature (10

Answer 1

Lechalteir principle says any change in equilibrium conditions will shift the equilibrium in that direction which will resist the change.

Factors

a) Increasing/ Decreasing the concentration of reactants or products:

If a reactant concentration is increased by adding more of it, the equilibrium will move to forward direction so that concentration of increased reactant can be decreased.

If a product concentration is increased by adding, the equilibrium will shift to backward direction so that concentration of increased product can be decreased.

If a reactant concentration is decreased by adding a reagent which can react with that reactant, the equilibrium will shift to backward direction so that concentration of decreased reactant can be increased.

If a product concentration is decreased by adding a reagent which can react with that product, the equilibrium will shift to forward direction so that concentration of decreased product can be increased.

b) Increase/ decrease in temperature

case I) If the reaction is exothermic in nature means heat releasing.

if we increase the temperature, the equilibrium will shift backwards to reduce the temperature of the system.

if we decrease the temperature, the equilibrium will shift forward to increase the temperature of the system.

case II) If the reaction is endothermic in nature means heat absorbing.

if we increase the temperature, the equilibrium will shift forward to use the temperature or heat given to the system.

if we decrease the temperature, the equilibrium will shift backward to increase the temperature of the system.

c) Increase / decrease in pressure:

If we increase the pressure equilibrium will shift to that side which has less number of moles.

If we decrease the pressure equilibrium will shift to that side which has more number of moles.

now lets solve the question

If concentration of carbon dioxide has to be decreased the equilibrium should shift to forward direction producing more of products.

a) nitrogen is a inert gas, in a closed vessel as the volume doesnot changes. There will be no effect of inert gas on the equilibrium constant or equilibrium direction. Hence no change in concentration of carbon dioxide. Hence it is false.

b) adding more NaOH will increase the concentration of reactant,  the equilibrium will move to forward direction so that concentration of increased reactant can be decreased. This will also decrease the concentration of other reactant i.e. carbon dioxide. Hence it is true.

c) increasing volume of container: it will decrease the pressure.

If we decrease the pressure equilibrium will shift to that side which has more number of moles. It will shift the equilibrium in backward direction. It will increase the concentration of carbon dioxide. Hence it is false.

d) lowering the temperature: If the reaction is exothermic in nature means heat releasing.

if we decrease the temperature, the equilibrium will shift forward direction to increase the temperature of the system. Hence will decrease the concentration of carbon dioxide. Hence it is true.