Question

Water (h2o) and methane (ch4) have similar molar masses. methane changes from a liquid to a gas at -161oc. water becomes a gas at 100oc. what could account for this difference

Answer 1

Answer is: hydrogen bond.
Hydrogen bonds are formed between water molecules and not between methane molecules.
The melting and boiling point depend on the strength of the ihydrogen bonds. Hydrogen bonding will cause the higher the melting and boiling points because more energy is needed to break bonds between molecules.