Equilibrium and catalysts

What is true at equilibrium?

• The forward and backward reactions occur at the same rate.

• The concentration of reactants and products remains constant.

Is R→ P forwards or backwards

Forwards

Is P→ R forwards or backwards?

Backwards

When does the equilibrium lie to the left?

When the concentration of reactants is greater than the concentration of products.

When does the equilibrium lie to the right?

When the concentration of products is greater than the concentration of reactants.

What do we say if the forward reaction is favoured?

The equilibrium has moved to the right.

What do we say if the backward reaction is favoured?

The equilibrium has moved to the left.

If a system is heated up, which reaction will be favoured?

Endothermic

If a system is cooled, which reaction will be favoured?

Exothermic

If the enthalpy change is negative, is the reaction exothermic or endothermic?

Exothermic

If the enthalpy change is positive, is the reaction exothermic or endothermic?

Endothermic

In a reaction with a negative enthalpy change , if you wanted to increase the yield, would you increase the temperature of the system or decrease it?

Decrease (to a moderate temperature)