Question

H2O2(1) ---> H2(g) + O2(g) delta H= 187 kJ/mol

Which way will the equilibrium shift if:
1. More H2 is added.
2.02 is removed
3. The temperature increases.
4. The volume is reduced.
5. Catalyst is added.
6. Inert gas is added.

Example: Ar​

Answer 1

(Introducing Le chatelier's principle to put my points more clearly. )

Le Chatelier's Principle : If any disturbance is caused to the equilibrium, then the equilibrium shifts in forward or backward direction to compensate the effect of disturbance.

$\rule{200}2$

1) More H2 is added

More H2 is added, means we are increasing the product side. Then by Le Chatelier's principle, equilibrium will shift backwards.

2) O2 is removed

Here product is being removed, so equilibrium will shift forward to make more product.

3) Temperature is increased

Here given that ΔH = 187 kJ/mole hence the reaction is endothermic. So on increasing temperature, reaction will move forward

4) The volume is reduced

Volume is reduced means equilibrium pressure is increased. When equilibrium pressure increases, reaction will try to move to that direction where it can compensate the increased pressure (that is, decrease the pressure). So it moves to the side where number of gas moles is less. Here, reaction will move backwards.

5) Catalyst is added

Catalyst just helps in reaching equilibrium faster, it doesn't shift direction of equilibrium. Hence no change.

6) Inert gas is added

If inert gas is added at constant volume, there is no effect on equilibrium (as it doesn't affect the pressure of other gases)

However if inert gas is added at constant pressure, the equilibrium pressure of already present gases decreases, hence by Le chatelier's principle equilibrium tries to compensate it by increasing the pressure. Hence in this case, reaction will move forward.

Answer 2

Answer:

Given :-

H2O2(1) ---> H2(g) + O2(g) delta H= 187 kJ/mol

Solution :-

• When more $\sf H_2$ will be added then it will increase so, It will move forward
• When $\sf O_2$ will remove then it will move forward
• Now, When temperature increases, So teh equilibrium will move forward
• Now, Volumes reduced then it will move backwards
• If catalyst will be added then no change
• When insert gas is added then there is no effect

Therefore,

Forward + Forward + Forward - Backward = Forward