Question

\[A{{l}_{4}}{{C}_{3}}\] on hydrolysis gives X gas. How many H atoms are present in an X molecule?

Answer 1

Hint: To solve this question we should know that hydrolysis is any chemical reaction in which a molecule of water ruptures one or more chemical bonds. We should know that aluminium carbide is a quite hard substance and is often used as an abrasive material.

Step by step answer:
We should know that \[A{{l}_{4}}{{C}_{3}}\] is carbide of aluminium. It has the appearance of pale yellow to brown crystals. It is stable up to$ 1400^oC$ . It decomposes in water with the production of methane.
Decomposition reaction of Aluminium carbide is as follows:
Aluminium carbide hydrolyses with the evolution of methane. The reaction proceeds at room temperature but is rapidly accelerated by heating.
\[A{{l}_{4}}{{C}_{3}}+12{{H}_{2}}O\to 4Al{{\left( OH \right)}_{3}}+3C{{H}_{4}}\uparrow \]
So, the “X” molecule is methane. And the number of hydrogen atoms present in X molecule or methane is 4. So, our correct answer is 4.
Additional information:
There are many ways through which we can produce aluminium carbide. It is prepared by direct reaction of aluminium and carbon in an electric arc furnace.
\[4Al\text{ }+\text{ }3C\to A{{l}_{4}}{{C}_{3}}\]
We can also make it by beginning with alumina, but it is less favourable because of generation of carbon monoxide.
\[2\text{ }A{{l}_{2}}{{O}_{3}}+9\text{ }C\text{ }\to \text{ }A{{l}_{4}}{{C}_{3}}+6CO\]
Silicon carbide also reacts with aluminium to yield aluminium carbide. This conversion limits the mechanical applications of SiC, because aluminium carbide is more brittle than silicon carbide.
\[4Al+3\text{ }SiC\to \text{ }A{{l}_{4}}{{C}_{3}}+3Si\]

Note: We should know about the applications of aluminium carbide. Aluminium carbide is used as an abrasive in high-speed cutting tools. It has approximately the same hardness as topaz. Aluminium carbide particles finely dispersed in aluminium matrix lower the tendency of the material to creep, especially in combination with silicon carbide particles.