G is positive, so K is much less than 1.

+G = forward reaction is unfavorable / nonspontaneous

Therefore, [reactants]equilibrium >> [products]equilibrium and it lies far to the left.

All that to say,** Since G is positive, K is much less than 1.**

G=-RTlnK

Since G is positive, (-RTlnK) has to be negative, and lnK will be positive when K is less than one..

Since K is much less than 1, the reaction below barely increases [H3O+] at all, so the pH is relatively close to 7, and slightly lower due to the slight increase of [H3O+] due to HEX3 acting as a bronsted acid.

HEX_{3}*(aq)* + H_{2}O*(l)* ⇌ H_{3}O^{+}*(aq)* + EX_{3}^{−}*(aq)*