farfis intermolecular forces multiple choice questions

Intermolecular Forces Sample Questions

1. The vapor pressure of a liquid increases exponentially with increasing temperature chieflybecause:

the fraction of high energy molecules increases much faster than the average energy. the average molecular mass increases. the strength of the intermolecular forces increases. the enthalpy of vaporization increases. atmospheric pressure increases.

2. A solute is most likely to be highly soluble in a solvent if the solute is _____ and thesolvent is ______.

ionic or polar, non-polar ionic or polar, polar non-polar, polar non-polar, ionic

3. The boiling point of CH4 is much lower than that of HF. This is because:

of ion-dipole interactions in CH4.

of hydrogen bonding in HF. of dipole-dipole interactions in CH4.

HF is more polarizable. CH4 is polar.

4. The concept of "like dissolves like" is illustrated by which of the following? NaCl (s) is more soluble in CCl4 than in water.

CuSO4(s) is more soluble in CCl4 than in water.

I2(s) is more soluble in CCl4 than in water.

CCl4 is soluble in water.

I2(s) is more soluble in water than in CCl4.

5. Molecular iodine would be most soluble in: water carbon tetrachloride vodka (ethanol and water) vinegar (acetic acid and water) equally soluble in all four

6. Which of the following best explains why the normal melting point of ICl(27.2°C) is somuch higher than that of Br2 (-7.2°C). The molecules of both substances have the samenumber of electrons.

the Cl atom in the ICl molecule is more polarizable than the Br atom in the Br2 molecule.

the ICl molecules have a lower molecular weight the ICl molecules undergo hydrogen bonding ICl molecules are polar iodine in ICl is more electronegative than bromine in Br2

7. At room temperature, F2 and Cl2 are gases, Br2 is a liquid, and I2 is a solid. This isbecause:

dipole-induced dipole interactions increase with molecular size. dispersion interactions increase with molecular size.

Intermolecular Forces Multiple Choice Questions http://www.chem.umass.edu/genchem/chem112/MCQ_Intermolecular...

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dipole-dipole interactions increase with molecular size. polarity increases with molecular size. dispersion interactions increase with molecular size and polarity increases with molecular

size.8. State why the normal melting point of ICl(27.2°C) is so much higher than that of Br2(-7.2°C). The molecules of both substances have the same number of electrons.

the Cl atom in the ICl molecule is more polarizable than the Br atom in the Br2 molecule.

the ICl molecules undergo hydrogen bonding the ICl molecules have a lower molecular weight ICl molecules are polar iodine in ICl is more electronegative than bromine in Br2

9. Why is the normal boiling point of hydrogen fluoride is so much higher than that ofhydrogen chloride, the hydride of the next element in group VIIA?

the HF molecules undergoes a higher degree of hydrogen bonding than HCl. the electron cloud in the HF molecule is more easily distorted (i.e. is more polarizable)

than that of HCl. the HF molecules have a lower dipole moment. HCl molecules are non-polar. chlorine in HCl is more electronegative than fluorine in HF.

10. The boiling point of water is about 200°C higher than one would predict from the boilingpoints of hydrogen sulfide and hydrogen selenide. One may explain this apparent anomaly bywhich of the following?

Water has the lowest molecular weight. Water is less polar than hydrogen sulfide and hydrogen selenide. The H-O covalent bond is much stronger than the H-S and H-Se bonds. The intermolecular attractive forces are much greater in water than in hydrogen sulfide

and hydrogen selenide. The water molecule is lighter than the other two molecules.

11. For a given substance, which of the following phase transitions should RELEASE themost energy.

Gas to liquid Solid to gas Gas to solid Solid to liquid Liquid to gas

12. Which one of the following molecules would be most polar? HF H2 HCl HBr HI

13. Based on the following information:CF4, Molecular Weight 87.99, Normal Boiling Point -182°CCCl4, Molecular Weight 153.8, Normal Boiling Point -123°C

The intermolecular forces of attraction in the above substances is described by which of thefollowing:


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dispersion (or London) forces dipole-dipole forces (permanent dipoles) ion-dipole forces gravitational forces repulsive forces

14. Based on the following information:CF4, Molecular Weight 87.99, Normal Boiling Point -182°CCCl4, Molecular Weight 153.8, Normal Boiling Point -123°C

Which of the above substances would have the higher equilibrium vapor pressure assumingthat both substances are in the liquid state at the same temperature?

CF4 CCl4 CF4 and CCl4 would have the same vapor pressure

impossible to determine from the information given 15. Based on the following information:CF4, Molecular Weight 87.99, Normal Boiling Point -182°CCCl4, Molecular Weight 153.8, Normal Boiling Point -123°C

The reason that CCl4 has a higher boiling point than CF4 is that:

CCl4 molecules are more polar

CCl4 molecules have a greater polarizability

CF4 molecule have a greater polarizability

CF4 molecules are more polar 16. One of the reasons that solid CuSO4 dissolves in water is:

instantaneous dipole-induced dipole forces (dispersion or London forces) between theCu2+ and the SO4

2- ions

the ion-dipole forces between the ions and the water molecules the electrostatic force of attraction between the Cu2+ and the SO4

2- ions

the hydrogen bonding between the water molecules instantaneous dipole-induced dipole forces (dispersion or London forces) between the

water molecules17. Solid iodine would be most soluble in which of the following solvents?

carbon tetrachloride water iodine would be equally soluble in water and carbon tetrachloride iodine would be insoluble in both water and carbon tetrachloride impossible to determine the relative solubilities


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farfis intermolecular forces multiple choice questions

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