Unit 3 - Equilibria & Chemical Energy Flashcards
What does adding a reactant/ removing a product do to effect the equilibrium
- Equilibrium will shift right
- Increased concentration of products
- Favours forward reaction
What does adding a product/ removing a reactant do to effect the equilibrium
- Equilibrium shifts left
- Increases concentration of reactants
- Favours backwards reaction
How does increasing temperature affect the equilibrium
- Increasing temperature favours endothermic reaction
- Equilibrium favours direction of endothermic reaction
How does decreasing temperature effect equilibrium
- Decreasing temperature favours endothermic reaction
- Equilibrium moves in direction of endothermic reaction
Is enthalpy change positive or negative for an endothermic reaction?
Positive
Is enthalpy change positive or negative for an exothermic reaction?
Negative
What are the bewares for equilibrium concentration?
- Adding an H ion where OH is involved in reaction causes neutralisation reaction
- Adding H ion when H is involved increases concentration of opposite reaction
- Adding AgNO3 forms precipitate reactions
How does decreasing pressure effect equilibrium
- More volume
- Favours reaction which produces more gas volumes
How does increasing pressure effect equilibrium
- Less volume
- Favours reaction which produces smaller gas volumes
How does adding a catalyst effect equilibrium
Only increases the rate equilibrium is achieved
For enthalpy of combustion questions, are answers positive or negative
Negative
State Hess’s law
The enthalpy change of a chemical reaction is independent of the route taken
Are breaking bonds endothermic or exothermic
Endothermic (+ve)
Are making bonds endothermic or exothermic
Exothermic (-ve)
What’s the formula for enthalpy change for bond enthalpy questions
🔺H = Bonds Broken(+ve) + Bonds made (-ve)
