Question

If end point occurs when h+ = oh- then isnt ph always 7

Answer 1

pH= -log[H+], [H+]= concentration of H+
[H+]= [OH-], means only H2O is source of H+ and OH-
at 25 degree C, dissociation constant of H2O is 10^-14, so, only at 25 degree C, pH+pOH= pkH2O= 14( where pOH= -log[OH-], pkH2O= -log( dissociation constant of H2O)= dissociation constant of H2O= [H+][OH-])
If temperature increases dissociation constant increases so, pH increases and temperature decreases dissociation constant decreases so, pH decreases