Question

When ethanol (CH3​CH2​OH) changes phase from the liquid to the gas, which bond(s)/forces are being broken?

A. C-H covalent bond
B. O-H covalent bond
C. O⋯H hydrogen bond
D. O-C covalent bond
E. More than one of the above

Answer 1

When ethanol changes phase from liquid to gas, the bond(s)/forces being broken are the intermolecular forces, specifically the hydrogen bonding between the oxygen atom of one ethanol molecule and the hydrogen atom of another ethanol molecule. The option (C) is correct.

Step-by-step explanation:

When ethanol (CH3CH2OH) changes phase from liquid to gas, the bond(s)/forces being broken are the intermolecular forces.

Specifically the hydrogen bonding between the oxygen atom of one ethanol molecule and the hydrogen atom of another ethanol molecule. Therefore, the correct answer is C. O⋯H hydrogen bond.