Diborane reacts with $HCl$ in the presence of $AlCl_3$ and liberates:

When $AlCl_3 \cdot 6H_2O$ is strongly heated,then it forms

Give important trends and anomalous properties of boron.

The correct statements from the following are:
$(A)$ The decreasing order of atomic radii of group $13$ elements is $Tl > In > Ga > Al > B$.
$(B)$ Down the group $13$ electronegativity decreases from top to bottom.
$(C)$ $Al$ dissolves in dil. $HCl$ and liberates $H_2$,but conc. $HNO_3$ renders $Al$ passive by forming a protective oxide layer on the surface.
$(D)$ All elements of group $13$ exhibit a highly stable $+1$ oxidation state.
$(E)$ Hybridisation of $Al$ in $[Al(H_2O)_6]^{3+}$ ion is $sp^3d^2$.
Choose the correct answer from the options given below:

Which of the following statements is incorrect?

When orthoboric acid is heated,the residue left is ...