3.1.3.7 Forces between molecules

Which compound has the highest boiling point?

• butanal

• butan-2-ol

• but-2-ene

• 1-fluorobutane

Which compound has the highest boiling point?

• CH₃CH₂CH₂OH

• CH₃CH₂CHO

• CH₃COCH₃

• CH₃COOCH₃

Which statement about intermolecular forces is not correct?

• Intermolecular forces exist between all simple molecules.

• Hydrogen bonding occurs between HBr molecules.

• Hydrogen bonding is the strongest intermolecular force in liquid ethanol.

• Hydrogen bonds occur between C=O and H−N in proteins.

Use your understanding of intermolecular forces to predict which of these compounds has the highest boiling point.

• HF

• HCl

• HBr

• HI

Which of these substances does not show hydrogen bonding?

• HF

• NH₃

• CH₃COOH

• CHF₃

Which of these substances has permanent dipole-dipole attractions between molecules?

• CCl₄

• C₂F₄

• (CH₃)₂CO

• CO₂

Which compound has the highest boiling point?

• C₂H₄

• C₂H₆

• CH₃NH₂

• CH₃F

Which one of the following statements is not correct?

• The first ionisation energy of iron is greater than its second ionisation energy

• The magnitude of the lattice enthalpy of magnesium oxide is greater than that of barium oxide.

• The oxidation state of iron in [Fe(CN)₆]³⁻ is greater than the oxidation state of copper in [CuCl₂]⁻

• The boiling point of C₃H₈ is lower than that of CH₃CH₂OH

The ester methyl ethanoate is hydrolysed as shown in the following equation.

Which one of the following compounds from the reaction mixture has no hydrogen bonding between its molecules when pure?

• CH₃COOCH₃(l)

• H₂O(l)

• CH₃COOH(l)

• CH₃OH(l)

This question is about the reaction between propanone and an excess of ethane-1,2-diol, the equation for which is given below.

In a typical procedure, a mixture of 1.00 g of propanone, 5.00 g of ethane-1,2-diol and 0.100 g of benzenesulphonic acid, C₆H₅SO₃H, is heated under reflux in an inert solvent. Benzenesulphonic acid is a strong acid.

Which one of the following statements is not true?

• Ethane-1,2-diol and water can form hydrogen bonds.

• Ethane-1,2-diol is soluble in water.

• Propane has a higher boiling point than ethane-1,2-diol.

• Y and water are polar molecules.