$A$ solution of sodium borate has a $pH$ of approximately

Calculate the $pH$ at the equivalence point in the titration of $25 \ mL$ of $0.1 \ M$ formic acid with a $0.1 \ M$ $NaOH$ solution (given that $pK_a$ of formic acid $= 3.74$). $[\log \ 2 = 0.30]$

Which one of the following salts gives an acidic solution in water?

Find the equilibrium constant for the equilibrium reaction:
$HCOO^{-} + H_2O \rightleftharpoons HCOOH + OH^{-}$
Given that the dissociation constant of formic acid is $K_a(HCOOH) = 1.8 \times 10^{-4}$.

Which of the following salts on dissolution in water gives $pH$ less than $7$ at $298 \ K$?

Calculate the $pH$ on mixing $100 \ mL$ of $0.2 \ M \ HCN$ with $400 \ mL$ of $0.05 \ M \ KOH$ at $25 \ ^\circ C$ ($pK_b$ for $CN^- = 8$).