Chapter 11: Solutions

How much heat energy, in kilojoules, is required to convert 61.0 g of ice at -18.0 C to water at 25.0 C?

29.0 kJ

How long would it take for 1.50 mol of water at 100.0 C to be converted completely into steam if heat were added at a constant rate of 19.0 J/s?

53.3 min

Acetone, H3CCOCH3, has a boiling point of 56 C. Based on the data given in the figure, would you expect acetone to have a high or lower vapor pressure than ethanol at 25 C?

Acetone has a higher vapor pressure.

Rationalize the difference in boiling points between CHCl3 (61 C) and CHBr3 (150 C)

CHBr3 has the higher boiling point because it has the higher molar mass, which leads to greater polarizability and stronger dispersion forces.

The boiling point of another member of this homologous series was found to be 309 K. What is the likely molecular formula for this compound?

CH^3CH^2CH^2CH^2CH^3

Intermolecular forces of H2Se

Dipole-dipole boding London dispersion forces

Consider equal volumes (say 1 L) of a given substance in the solid, liquid, and gas phases. Arrange them in order of decreasing mass based on the trend for the average substance. If the mass difference between samples is relatively small (10% or less), rank the items as equivalent. Rank from greatest to least mass.

Greatest Mass: 1 L of substance in the liquid phase 1 L of substance in the solid phase least mass: 1 L of substance in the gas phase

Rationalize the difference in boiling points between the members of HF (20 C) and HCl (-85 C)

HF has the higher boiling point because hydrogen bonding is stronger than dipole - dipole forces.

Intermolecular forces of CH^3CH^2OH

Hydrogen-bonding London dispersion forces Dipole - dipole bonding

Rationalize the difference in boiling points between Br2 (59 C) and ICl (97 C)

ICl has the higher boiling point because it is a polar molecule.

Which of these kinds of interactions are broken when a liquid is converted to a gas?

Intermolecular interactions are broken when a liquid is converted to a gas.

Which is generally stronger, intermolecular interactions or intramolecular interactions?

Intramolecular interactions are generally stronger.

Intermolecular forces of SO2

London dispersion forces Dipole - dipole bonding

Match each description to the appropriate phase of matter.

Solid - a substance with a fixed volume and fixed shape Liquid - a substance with a fixed volume and no fixed shape Gas - a substance with no fixed volume or shaped

When popcorn is heated over a flame, the kernel bursts open. Why does this occur?

The air and water vapor inside the corn kernel is expanding.

As a metal such as lead is heated past its melting point, what happens to the average distance between the atoms?

The average distance between the atoms increases.

As a metal such as led is heated past its melting point, what happens to the average kinetic energy of the atoms?

The average kinetic energy increases.

Compare the viscosity of neopentane (CH3)4C and n-pentane.

You would expect the viscosity of n-pentane to be larger mainly because the long, cylindrical shape results in stronger dispersion forces when compared to the other hydrocarbon

Compared the viscosity n-butane, CH3CH2CH2CH3, to the viscosity of n-pentane, CH3CH2CH2CH2CH3.

You would expect the viscosity of n-pentane to be larger mainly due to one more carbon atom in the chain.

To form a hydrogen bond, what the non-hydrogen atom (N,O, or F) involved in the bond posses?

a nonbonding electron pair

In the mountains, water in an open container will boil when,

its vapor pressure equals atmospheric pressure.

The boiling points for a set of compounds in a homologous series can be qualitatively predicted using intermolecular force strengths. Using their condensed structural formulas, rank the homologous series for a set of alkanes by their boiling point. Rank from highest to lowest point

(Highest) heptane 3,3 - dimethylpentane hexane butane (lowest)