Which of the following is the strongest reducing agent in an aqueous medium?

Why are lithium salts commonly hydrated and those of the other alkali ions usually anhydrous?

Give a comparison of properties between lithium and other alkali metals.

$A$ certain metal is used in the preparation of an antacid. This metal accidentally catches fire,which cannot be extinguished using $CO_2$. Which metal is this?

Comment on each of the following observations:
$(a)$ The mobilities of the alkali metal ions in aqueous solution are
$Li^{+} < Na^{+} < K^{+} < Rb^{+} < Cs^{+}$
$(b)$ Lithium is the only alkali metal to form a nitride directly.
$(c)$ $E^{\circ}$ for $M^{2+}_{(aq)} + 2e^{-} \longrightarrow M_{(s)}$ (where $M = Ca, Sr$ or $Ba$) is nearly constant.

$NaOH$ is prepared by the method: