Question

c) given the reaction explain hoe equilibrium. would be reestablished after each of the following stresses are applied

4 NH3 +3O2 —> 2N2 +6 H2O

A) addition of water

B) Removal of Ammonia

C) increace of the valume of container

D) loweing of reaction temperature

Answer 1

First, let us state the Le Chatelier principle which deals with changes in an equilibrium:

The statement is as follows:

If any equilibrium is disturbed, that is, change in conditions such as P,T, concentration, partial pressure, etc.., the system will counterbalance such change in order to favour the system's equilbirium.

• Change in concentration
• Change in pressure
• Change in temperature

For the reaction:

4 NH3 +3O2 —> 2N2 +6 H2O

a)

addition of water --> increases products side, therefore the counter balance goes towards the formation of NH3 O2 (left side)

b)

Removal of Ammonia --> NH3,

decrease in reactants side, the countebalance is to produce even more NH3, so shift goes to the left

c)

increase in Volume --> decreases Pressure

decrease in pressure --> Favours the least mol of gases

left side = 4+3 = 7 mol; right side = 2+6 = 8 mol

therefore, reactants will be favoured, shift goes to the left

d)

This must be exothermic, since it is fuel + oxidant = release of heat

the HRxn = H(2N2 +6 H2O ) - H(6*4 NH3 +3O2) = (-241.8) - (4*-45.9) = -1267

decrease in T:

favours MORE products, since heat is removed, so more products can form