3.2.3 - Chemical Equilibrium

Question 1

What effect does increasing temperature have on equilibrium

Answer 1

• HIgher temperatures favours endothermic reactions
• So so positions of equilibrium will move to the _____ side (side of endothermic reaction products)
• • This only works in homogeneous equilibria (the same state/phase)

Question 2

What effect does increasing pressure have on equilibrium

Answer 2

• Higher pressure favors side with few gaseous moles
• This only works in homogeneous equilibria (the same state/phase)

Question 3

What affect does decreasing temperature have on equilibrium

Answer 3

Favours exothermic reactions so postions of equilibrium will move to the _____ side (side of exothermic reaction products)
- - This only works in homogeneous equilibria (the same state/phase)

Question 4

problems with low temperature

Answer 4

• Slow rate of reaction.

Question 5

Problems with high temperature

Answer 5

• Expensive
• May be explosive which is dangerous

Question 6

Effect of catalyst on equilibrium

Answer 6

No effect.

• but it will speed up the rate at which the
  equilibrium is achieved.
  It does not effect the position of equilibrium because it speeds up the rates of the forward and
  backward reactions by the same amount.

Question 7

Effect of concentration on equilibrium

Answer 7

It will increase the yield of the opposite side that con has been increased in (it will do the opposite)

If you decrease con of one side, it will increase yield of whatever has been decrease.

Question 8

Kc formula

Answer 8

Question 9

How do you work out the units in kc

Answer 9

Swap the brackets for moldm^-3

if there is a 1/ moldm^-3 then you invert the signs so its mol^-1 dm³

Question 10

Effects of increasing temp on kc.

Answer 10

Increase temp = endothermic = shift kc to the side of the endothermic

• In this scenario because the you increase the yield of reactants you will have to divide by a bigger number which is why kc drops.

decrease in temp = exothermic = shifts kc to the side of the exothermic reaction

• your increasing products giving you a bigger top number so kc increases

Question 11

What affects do catalyst, concentration and pressure have on kc

Answer 11

No effect

Question 12

Quick things to remember about kc

Answer 12

Liquid and solid concentrations are constant,
and are not included in heterogeneous Kc expressions.

Question 13

Answer 13

Kc increases bc we know that the reaction is endothermic from this sign (H>0) so H must be atleats +1.

Therfore kc shifts to the RHS as higher temps favours endothermic reactions.

• So the numerator value increase so kc increases