Intermolecular Forces and Macroscopic Properties

Liquids can form spherical elastic film to minimize surface area.

What intermolecular forces are responsible for the formation of this film

in water?

• dipole-induced dipole

• H-bonding

• ion-induced dipole

• London dispersion forces

Which among the following is the amount of energy required to stretch

or increase the surface of a liquid by a unit area (ex., 1 cm2)?

• heat of vaporization

• specific heat

• surface tension

• vapour pressure

How is the ability of water molecules to move against gravity referred

to?

• capillary action

• surface tension

• temperature

• viscosity

Tags

NGSS.HS-ESS2-5

Substances like heavy syrup and molasses flow slower than water.

How is the ability of these substances to resist flow called?

• capillary action

• pressure

• surface tension

• viscosity

What is the term that pertains to the pressure exerted by the vapor from

the evaporation of a liquid or solid above a sample of the liquid or solid

in a closed container?

• boiling point

• capillary action

• surface tension

• vapour pressure

What is true about liquids with strong intermolecular forces?

• Vapour pressure is low

• Vapour pressure is high.

• Viscosity tends to be high.

• Viscosity is immeasurable

What happens when the vapour pressure of a liquid becomes equal

to the atmospheric pressure?

• The liquid will boil.

• The vapour will condense.

• Melting of the solid form will start.

• There will be freezing of the liquid.

The atmospheric pressure on top of a mountain is lower than at sea

level. As a consequence, what will happen to the cooking time of an

egg on top of the mountain?

• The egg will cook faster since the boiling temperature will be

  lower.

• The egg will cook at a shorter time since the boiling temperature

  will be higher.

• The egg will cook at a longer time due to a lower boiling

  temperature.

• The egg will cook at a shorter time due to higher boiling

  temperature.

Tags

NGSS.HS-PS3-4

Sodium chloride is completely soluble in water. What is responsible

for its solubility in water?

• Na+ and Cl- ions are favorable sites for H-bonding to form.

• The ions in NaCl participate in ion-induced dipole attractions with

  water.

• The presence of charged ends in NaCl enables dipole-dipole

  interaction with water.

• London dispersion forces in NaCl predominate leading to strong

  dipole interactions with water.

Tags

NGSS.HS-PS2-4

Xenon has a greater atomic weight than neon. Xe has 131.3 amu while

Ne has 20.2 amu. The boiling points are 166.1K and 27.3K, respectively.

How do intermolecular forces account for the difference?

• Dipole- dipole interaction is greater in Xe than Ne so more

  energy is needed to break the bonds.

• H-bonding is greater for substances with higher atomic weight

  so greater energy is needed to change Xe to vapour.

• Atomic weight increases the chance of lesser dispersion forces

  so greater energy is needed to separate Xe atoms to change to

  vapour

• London dispersion forces are greater in substances with

  heavier atomic weight so greater energy is needed to separate

  the atoms of Xe than Ne.

Tags

NGSS.HS-PS3-4