Which of the following is added to borax to obtain boric acid?

Two students were given the task to prepare an adduct $NH_3 \to BH_3$ at low temperature :-
Student $I$ :- She mixed $B_2H_6$ and $NH_3$
Student $II$ :- He mixed $B_2H_6$ with $THF$ followed by addition of $NH_3$
Which student is expected to get the $CORRECT$ final product?

The number of $2$-centre-$2$-electron and $3$-centre-$2$-electron bonds in $B_2H_6$,respectively,are

Explain what happens when boric acid is heated.

The correct formula of borax is $Na_2[B_4O_5(OH)_4] \cdot 8H_2O$. If the formula is represented as $Na_2[B_4O_5(OH)_x] \cdot yH_2O$,then the sum of $x$ and $y$ is:

$A$ group $13$ element '$X$' reacts with chlorine gas to produce a compound $XCl_3$. $XCl_3$ is electron deficient and easily reacts with $NH_3$ to form $Cl_3X \leftarrow NH_3$ adduct,however,$XCl_3$ does not dimerize. $X$ is