Question
$$A{l_2}{O_3}$$ can be converted into anhydrous $$AlC{l_3}$$ by heating
A.
$$A{l_2}{O_3}$$ with $$HCl$$ gas
B.
$$A{l_2}{O_3}$$ with $$NaCl$$ in solid state
C.
a mixture of $$A{l_2}{O_3}$$ and carbon in dry $$C{l_2}$$ gas
D.
$$A{l_2}{O_3}$$ with $$C{l_2}$$ gas.
Answer :
a mixture of $$A{l_2}{O_3}$$ and carbon in dry $$C{l_2}$$ gas
Solution :
$$A{l_2}{O_3}$$ may be converted into anhyd. $$AlC{l_3}$$ by heating a mixture of $$A{l_2}{O_3}$$ and carbon in dry chlorine.
\[A{{l}_{2}}{{O}_{3}}+3C+\underset{\text{Hot and dry}}{\mathop{3C{{l}_{2}}}}\,\to \underset{\text{Anhy}\,AlC{{l}_{3}}}{\mathop{A{{l}_{2}}C{{l}_{6}}}}\,\]
NOTE
Anhydrous $$AlC{l_3}$$ exists in the form of dimer as $${A{l_2}C{l_6}}$$