What is obtained when an aqueous solution of aluminum chloride is heated to dryness?

Which of the following statements is correct?

Diborane reacts with ammonia under different conditions to give a variety of products. Which one among the following is not formed in these reactions?

Describe the general trends in the following properties of the elements in Groups $13$ and $14$.
$(A)$ Atomic size
$(B)$ Ionization enthalpy
$(C)$ Metallic character
$(D)$ Oxidation states
$(E)$ Nature of halides

The correct statements from the following are $:$
$(A)$ $Tl^{3+}$ is a powerful oxidising agent
$(B)$ $Al^{3+}$ does not get reduced easily
$(C)$ Both $Al^{3+}$ and $Tl^{3+}$ are very stable in solution
$(D)$ $Tl^{+}$ is more stable than $Tl^{3+}$
$(E)$ $Al^{3+}$ and $Tl^{+}$ are highly stable
Choose the correct answer from the options given below $:$

Identify the correct statements from the following:
$(a)$ In orthoboric acid, boron is in planar geometry.
$(b)$ In $BCl_3 \cdot NH_3$, boron has tetrahedral geometry.
$(c)$ Aqueous solution of borax is acidic.