Which of the following processes will not yield anhydrous $AlCl_3$?

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?

Complete the following chemical equations:
$4BF_{3} + 3LiAlH_{4} \to 2B_{2}H_{6} (X) + 3LiF + 3AlF_{3}$
$B_{2}H_{6} (X) + 6H_{2}O \to 2H_{3}BO_{3} (Y) + 6H_{2}$
$B_{2}H_{6} (X) + 3O_{2} \xrightarrow{\Delta} B_{2}O_{3} + 3H_{2}O$

Boric acid is not used in which of the following?

Boron halides behave as Lewis acids because of their nature.

Consider the following reactions.
$Na_{2}B_{4}O_{7} \xrightarrow{\Delta} 2 X + Y$
$CuSO_{4} + Y \xrightarrow{\text{Non-Luminous flame}} Z + SO_{3}$
$2Z + 2X + \text{Carbon} \xrightarrow{\text{Luminous flame}} 2Q + Na_{2}B_{4}O_{7} + CO$
The oxidation states of $Cu$ in $Z$ and $Q$, respectively are: