Answer
(a) Very low surface tension means the intermolecular forces in the liquid are very weak.
(b) Very low critical temperature means it is very difficult to liquify a gas because intermolecular forces are very weak; thus, the atoms/molecules will not hold strongly together.
(c) Very low boiling point means the intermolecular forces in the liquid are very weak; thus, it is easy to break the intermolecular forces in the liquid and evaporate.
(d) Very low vapor pressure means the intermolecular forces in the liquid are very strong; thus, it is difficult to evaporate liquid and thus low vapor pressure.
Therefore, only (d) indicates very strong intermolecular forces in a liquid.
Work Step by Step
(a) Very low surface tension means the intermolecular forces in the liquid are very weak.
(b) Very low critical temperature means it is very difficult to liquify a gas because intermolecular forces are very weak; thus, the atoms/molecules will not hold strongly together.
(c) Very low boiling point means the intermolecular forces in the liquid are very weak; thus, it is easy to break the intermolecular forces in the liquid and evaporate.
(d) Very low vapor pressure means the intermolecular forces in the liquid are very strong; thus, it is difficult to evaporate liquid and thus low vapor pressure.
Therefore, only (d) indicates very strong intermolecular forces in a liquid.
