chem multiple choice

The table above shows the structural formulars and molar masses for three different compounds. Which of the following is a list of the compounds in the order of increasing boiling points?

Bhutane<acetone< 1-propanol

A sample of a hard, solid binary compound at room temperature did not conduct electricity as a pure solid but became highly conductive when dissolved in water. Which of the following types of interactions is most likely found between the particles in the substance?

Ionic Bonds

The molecular formula and molar mass of two straight-chain hydrocarbons are listed in the table above. Based on the info in the table, which compound has the higher boiling point, and why? (Ethane, C2H6, MM=30g/mol and Butane, C4H10, MM=58g/mol)

C4H10 because it has more electrons, resulting in greater polarizability and stronger dispersion forces.

In which of the following liquids do the intermolecular forces include dipole-dipole forces?

CH2F2(l)

Which of the following arranges the molecules N2, O2, and F2 in order of their bond enthalpies, from least to greatest?

F2<O2<N2

Which of the following has the bonds arranged in order of decreasing polarity.

H-F>N-F>F-F

Which of the following has the highest boiling point and why? Ne, HF, C2H6, CH4

HF, because its molecules form hydrogen bonds

At room temperature I2(s) is a molecular solid. Which of the following provides a characteristic of I2(s) with a correct explanation?

It is not a good conductor of electricity because its valence electrons are localized in bonding and nonbonding pairs.

On the basis of molecular structure and bond polarity, which of the following compounds is most likely to have the greatest solubility in water?

NH3

A student is given a sample of a pure, white crystalline substance. Which of the following would be most useful in providing data to determine if the substance is an ionic compound?

Testing the electrical conductivity of an aqueous solution of the substance.

Which best helps to explain why CCl4 is a liquid whereas CI4 is a solid when both are at 25 degrees C.

The London Dispersion Forces are stronger in CL4 than in CCL4 because CL4 has a more polarizable electron cloud than CCL4.

The potential energy of a system of two atoms as a function of their internuclear distance is shown in the diagram above. Which of the following is true regarding the forces between the atoms when their intermolecular distance is x?

The attractive and repulsive forces are balanced, so the atoms will maintain an average internuclear distance x.

Benzene, C6H6, has the structure shown above. Considering the observation that benzene is only sparingly soluble in water, which of the following best describes the IMFs of attraction between water and benzene?

There are dipole-induced dipole and London dispersion interactions between water and benzene.

The BF3 molecule is nonpolar , whereas the NF3 molecule is polar. Which of the following statements accounts for the difference in polarity of the two molecules?

Unlike BF3, NF3 has a nonpolar geometry due to an unshared pair of electrons on the N atom.

The PE as a function of internuclear distnace for 3 diatomic molecules, X2, Y2, and Z2 is shown in the graph above. Baes on the data in the graph, which of the following correctly identifies the diatomic molecules, X2, Y2, and Z2?

X2, Y2, Z2= H2, N2, O2

Which of the following statements about delta H for the reaction is correct?

deltaH>0 because energy is required to break the N-N bond.