Question

Match each type of titration to its ph at the equivalence point for solutions at 25 ∘c. drag each item to the appropriate bin. view available hint(s) resethelp ph less than 7 ph equal to 7 ph greater than 7

Answer 1

The complete question;
Match each type of titration to its pH at the equivalence point.
Weak acid, strong base
Strong acid, strong base
Weak base, strong acid

pH less than 7
pH equal to 7
pH greater than 7
Answer:
weak acid, strong base - pH greater than 7
Strong acid, strong base - pH equal to 7
Weak base, strong acid - pH less than 7
Strong acids dissociate completely to give out H⁺ ions. 
Strong bases dissociate completely to give out OH⁻ ions.
When strong acids and strong bases are mixed the dissociated H⁺ and OH⁻ ions  react and neutralise each other, making the solution neutral.
Weak acids cannot completely dissociate, only a fraction of H⁺ ions are dissociated. Same applies for weak bases.
When weak acid and strong base is mixed, whilst the strong acid completely dissociates, weak base only partially dissociates. Therefore the amount of H⁺ ions is greater than OH⁻ ions, overall pH is more acidic, hence less than 7.
When strong base and weak acid are mixed, strong base completely dissociates giving OH⁻ ions and weak acid only partially dissociates, therefore amount of OH⁻ ions is greater than H⁺ ions, more basic hence pH is greater than 7.