Which one is a Lewis acid?

The ionization constants of two bases $AOH$ and $BOH$ are $K_{b1}$ and $K_{b2}$ respectively. Their relationship is $pK_{b1} < pK_{b2}$. Which of the following does not represent the base with the highest $pH$?

The conjugate base of hydrazoic acid $(N_3H)$ is .......

The neutralization of a strong acid by a strong base liberates an amount of energy per mole of $H^{+}$ that:

Which of the following species are only Lewis acids but not Bronsted acids from $CO_{2}$,$BCl_{3}$,$NH_{3}$,$CH_{3}NH_{2}$,$NO_{2}^{+}$,and $C_{6}H_{5}NH_{3}^{+}$?

Which one of the following statements is not correct?