Hydrolysis of aluminum carbide – equation and nature of the reaction

Al₄C₃ is a bi­na­ry com­pound of alu­minum and car­bon which is bro­ken down quite eas­i­ly by wa­ter (hy­drolyzes) or by di­lut­ed so­lu­tions of acids.

Alu­minum car­bide is a quite hard sub­stance and is of­ten used as an abra­sive ma­te­ri­al.

The com­pound is an odor­less pow­der of a yel­low-brown col­or. It is a heat-re­sis­tant sub­stance with a melt­ing point of over 2100 °С.

Ob­tain­ing alu­minum car­bide

Di­rect in­ter­ac­tion of car­bon with alu­minum in arc fur­naces:

4Al + 3C → Al₄C₃

In­ter­ac­tion of alu­minum ox­ide with car­bon at a tem­per­a­ture of 1800 °С:

2Al₂O₃ + 9C → Al₄C₃ + 6СО↑

Hy­drol­y­sis is a re­ac­tion that oc­curs be­tween a sub­stance and wa­ter, as a re­sult the sub­stance and wa­ter break down, and new com­pounds form. Al₄C₃ is a salt-like car­bide, which is es­sen­tial­ly the prod­uct of the dis­place­ment of the hy­dro­gen atom in meth­ane by met­al atoms. So in its hy­drol­y­sis, re­verse dis­place­ment eas­i­ly oc­curs, and meth­ane forms.

Equa­tion of the alu­minum car­bide hy­drol­y­sis:

Al₄C₃ + 12H₂O → 4Al(OH)₃ ↓+ 3CH₄ ↑

The hy­drol­y­sis of alu­minum car­bide is an ir­re­versible re­ac­tion.

When this re­ac­tion takes place, meth­ane and alu­minum hy­drox­ide are re­leased. This re­ac­tion is a sim­ple method of ob­tain­ing meth­ane in the lab­o­ra­to­ry. Click here to find easy ex­per­i­ments of ob­tain­ing dif­fer­ent gas­es at home.