Which one of the following statements is not true regarding diborane $(B_2H_6)$?

$H_3BO_3$ is

Which base among the following reacts with diborane to cleave it unsymmetrically?

Sodium borohydride upon treatment with iodine produces a Lewis acid $(X)$,which on heating with ammonia produces a cyclic compound $(Y)$ and a colourless gas $(Z)$. $X, Y$ and $Z$ are $....$

On the basis of reactions given below identify $X, Y, Z$.
$Boron \xleftarrow{Mg \, or \, Fe} X \xleftarrow{\Delta} B(OH)_3 + \text{Gas-}Z$
$B(OH)_3 \xleftarrow{H_2O} Y \xrightarrow{2NH_3/\Delta} \text{Inorganic benzene}$

$X$ reacts with aqueous $NaOH$ to form $Y$ and releases $H_2$ gas. When the aqueous solution of $Y$ is heated at $323 \ K - 333 \ K$ and $CO_2$ gas is passed through it,it yields $Al_2O_3 \cdot xH_2O$ (often represented as $Al(OH)_3$) and $Z$. Heating $Z$ at $1200 \ ^\circ C$ gives $Al_2O_3$. Identify $X, Y,$ and $Z$.