Chapter 26 - van der Waals' forces between molecules

Who invented van der Waals' forces?

• Kelvin

• Mendeleev

• No one

• J D van der Waals

Which is the correct description about van der Waals' forces?

• They are the weakest of the intermolecular forces arising from instantaneous dipole - induced dipole interactions.

• They are the strongest of the intermolecular forces arising from dipole - dipole interactions.

If van der Waals' forces hold the layers of graphite together, why does it have a high melting point?

• The large surface area of the graphite layers make the van der Waals' forces strong.

• The carbon atoms within the layers are held together by strong covalent bonds.

Which of the following statements about hydrogen bromide are correct?

(1) Atoms within its molecules are held together by covalent bonds.

(2) Its molecules are held together by van der Waals’ forces.

(3) Its molecules are held together by hydrogen bonds.

• (1) and (2) only

• (1) and (3) only

• (2) and (3) only

• (1), (2) and (3)

Which of the following molecules are held together by van der Waals’ forces and hydrogen bonds?

• Ammonia

• Carbon dioxide

• Chloromethane

• Hydrogen sulphide

Which of the following gives the correct order of boiling points of H₂O, HCl and HF?

• H₂O > HCl > HF

• H₂O > HF > HCl

• HF > HCl > H₂O

• HF > H₂O > HCl

Tags

NGSS.HS-PS1-3

Which of the following gives the correct order of increasing melting point for the substances shown below?

(1) CH₃CH₂CH₂CH₃

(2) CH₃CH₂CH₂CH₂CH₃

(3) CH₃CH₂CH₂CH₂OH

• (1), (2), (3)

• (2), (1), (3)

• (3), (2), (1)

• (3), (1), (2)

The ability of a liquid to flow is linked to the strength of its intermolecular forces. Suggest which of these liquids flows the slowest when poured.

• Propane-1,2,3-triol

• Propane-1,2-diol

• Pentane

• Butane