Question

o-Hydroxy benzaldehyde is a liquid at room temperature while p-hydroxy benzaldehyde is a_____ melting solid.

• A. low
• B. equal
• C. high
• D. none

Answer 1

The correct option is C high

o-Hydroxy benzaldehyde show intramolecular H-bonding or chelation, which are weaker than intermolecular H-bonding in p-hydroxy benzaldehyde. Thus the molecules in p-hydroxy benzaldehyde are associated which is not the case in o-hydroxy benzaldehyde.
Hence, o-Hydroxy benzaldehyde is a liquid at room temperature while p-hydroxy benzaldehyde is a high melting solid.