Question

Which TWO of the following molecules are capable of hydrogen bonding?

a) 2-methylpropanoic acid
b) 1-methyl-2-propanone
c) 2-methylpropanal
d) 2-methyl-2-propanol
e) methyl propanoate

Answer 1

The two molecules capable of hydrogen bonding are 2-methylpropanoic acid (a) and 2-methylpropanal (c), as they contain hydrogen atoms bonded to a highly electronegative atom, like oxygen, and have the proper structural features to engage in hydrogen bonding.

Step-by-step explanation:

The question asks which two molecules are capable of hydrogen bonding. To engage in hydrogen bonding, a molecule must contain a hydrogen atom bonded to a highly electronegative atom like oxygen, nitrogen, or fluorine, which in turn can form a bond to a lone pair of electrons on another electronegative atom.

The correct answers are:

1. 2-methylpropanoic acid (a), because it contains both a hydrogen atom attached to an oxygen atom and a carboxyl group (-COOH) that can act as both a hydrogen bond donor and acceptor.
2. 2-methylpropanal (c), because it has a C=O bond and a hydrogen atom bonded directly to the electronegative oxygen, allowing it to form hydrogen bonds.

The other compounds listed either do not have the necessary O-H or N-H bonds (1-methyl-2-propanone, 2-methyl-2-propanol, and methyl propanoate) or do not have the electronegativity difference required for hydrogen bonding.