Catalysts are required for the production of both ethanol from ethylene and ethylene from ethanol - HSC - SSCE Chemistry - Question 2 - 2006 - Paper 1

In the production of ethanol, Catalyst A must be a dilute acid, commonly H+, to favor the hydration of ethylene. For the conversion of ethanol back to ethylene, Catalyst B requires a concentrated acid, which is typically conc H+.

Thus, the identities are:

• Catalyst A: dilute H+
• Catalyst B: conc H+

So the correct answer is (A).