Nature of Chemical Reactions/Equilibrium

Question 1

Open and closed systems

Answer 1

Open system
- can exchange matter and energy with the surroundings

Closed system
- can only exhange energy with their surroundings

Question 2

Reversible and irreversible reactions

Answer 2

Reversible
- when products can be used to reform reactants
- reactions that can proceed in the forward and backwards direction
- can only occur in a closed system

Irreversible
- reactions that can only proceed in the forward direction

Question 3

Equilibrium

Answer 3

• when the rate of production of products is = to rate of reformation of reactants in a reversible reaction

dynamic equilibrium
- when the forward/backward reactions are still occuring

Question 4

When is equilibirum determiend in a concentration/time graph

Answer 4

• as the concentration of reactants decrease, concentration of products increase
• over time, concentration of both level off and become constant –> equilibrium

Question 5

Why does concentration never = zero

Answer 5

• as more products produced, greater chance of reactants being re-formed

Question 6

what can concentration/time graphs indicate

Answer 6

The rate of reaction
- the steeper the curve, the quicker the RoR / the more that is being made at the point in time

Question 7

Position of equilibrium

Answer 7

• compares the concentration of products/reactants at equilibrium
• if PoE lies to the right –> the reaction favours the products
• if PoE lies to the left –> reaction favours the production of reactants