The alum used for purifying water is

Which of the following statements is correct?

The correct Lewis acidity order of $BX_3$ is:

Select the correct statements for diborane $(B_2H_6)$:
$1.$ Boron is approximately $sp^3$ hybridized.
$2.$ The $H-B-H$ bridge angle is $180^o$.
$3.$ There are two terminal $B-H$ bonds for each boron atom.
$4.$ There are only $12$ bonding electrons available.

Consider the following statements for diborane $(B_2H_6)$:
$1.$ Boron is approximately $sp^3$ hybridized.
$2.$ $B-H-B$ angle is $180^{\circ}$.
$3.$ There are two terminal $B-H$ bonds for each boron atom.
$4.$ There are only $12$ bonding electrons available.
Which of these statements are correct?

The tendency of $BF_3$,$BCl_3$ and $BBr_3$ to behave as Lewis acid decreases in the sequence