Topic 5 Flashcards
What happens when concentration of reactant is increased?
Increases rate of forward reaction, equilibrium moves to the right
What happens when concentration of product is increased?
Increases the rate of the reverse reaction. Equilibrium moves to the left
What happens when temperature is increased?
Favours endothermic reaction. Equilibrium moves in direction of endothermic reaction
What happens when pressure is increased?
Favours a decrease in pressure. Equilibrium moves to side with fewest moles of gas.
What happens when a catalyst is used?
No effect
What is equilibrium constant equation?
K = [C]c X [D]d/[A]a X [B]b
An acid is a proton …
Donor
A base is a proton …
Acceptor
What is a conjugate base
Acid - H+
What is a conjugate acid?
Base + H+
What do strong acids do in aqueous solutions
They completely dissociate into ions
What do weak acids do in aqueous solutions?
They only partially dissociate into ions
Why is an acidic salt?
The OH ions are removed from the equilibrium, forming molecules of the weak base. The water equilibrium moves to the RHS to replace the OH ions, producing an excess of H, therefore ph < 7
Why is an alkaline salt
The H ions of the salt are removed from the equilibrium, forming molecules of weak acid. The water equilibrium moves to the RHS to replace the H ions, producing an excess of OH, therefore pH > 7
What is Kw equation?
[H3O+][OH-]
What is Kw at 25oC
1.01 X 10-14
What are the concentrations of H3O and OH at 25oC?
1.005 X 10-7
What happens when an acid is added to an acidic buffer?
When the acid is added the H ions react with the CHCOO ions to produce molecules of the weak acid. As long as there is a large supply of CHCOO ions from the salt the ph remains unchanged
What happens when an alkali is added to an acidic buffer?
When the alkali is added the OH ions react with the H ions and form water. The acid equilibrium moves to the right to replace the H ions. The ph remains unchanged
What happens when an acid is added to a basic buffer?
When the acid is added the H ions react with the OH ions and form water. The alkali equilibrium moves to the right, and the alkali molecules dissociate to replace the OH ions. The pH is maintained
What happens when an alkali is added to a basic buffer?
When the alkali is added, the OH ions react with the NH4 ions to produce molecules of the weak alkali. As long as there is a large supply of NH4 ions from the salt, the pH remains unchanged
Strong acid - strong alkali titration rapid change?
Between 4 - 10
Strong acid - weak alkali titration rapid change?
Between 3 - 7
Weak acid - strong alkali titration rapid change?
Between 8 - 11
Weak acid - weak alkali titration rapid change
No rapid change, no possible indicator
