Thermal cracking, catalytic cracking and steam cracking are all used to convert alkane molecules into smaller molecules. Identify which one of the three types of cracking is used to crack a hexane molecule, C₆H₁₄, into propane and an alkene molecule, and state the equation involved.

steam cracking;

\({{\text{C}}_{\text{6}}}{{\text{H}}_{{\text{14}}}} \to {{\text{C}}_{\text{3}}}{{\text{H}}_{\text{8}}} + {{\text{C}}_{\text{3}}}{{\text{H}}_{\text{6}}}\);

Ignore state symbols.

Most candidates were able to state the equation (in quite a few cases the molecular formula of propane was not known) for the cracking process, but only about half correctly identified steam cracking.