Chem Test One Final

Water vapor is less dense than ice because

• molecules in the gas phase have more potential energy than in solids.

• molecules in the gas phase have more space between them than in solids.

• gaseous molecules have less mass.

• molecules in the gas phase have more kinetic energy than in solids.

• molecules in the gas phase are in constant motion.

The mass of a sample is 550 milligrams. Which of the following expresses that mass in kilograms?

• 5.5 × 10⁻⁴ kg

• 5.5 × 10⁵ kg

• 5.5 × 10⁻⁶ kg

• 5.5 × 10⁸ kg

• 5.5 × 10⁻¹ kg

The SI unit of speed (velocity) is

• m/h.

• m/s.

• km/s.

• km/h.

• None of these choices are correct.

Acetone, which is used as a solvent and as a reactant in the manufacture of Plexiglas®, boils at 56.1°C. What is the boiling point in degrees Fahrenheit?

• 43.4°F

• 101°F

• 159°F

• 133°F

• 69.0°F

The appropriate number of significant figures in the result of 15.234 × 15.208 is

• 5.

• 2.

• 4.

• 3.

• 6.

The result of (3.8621 × 1.5630) – 5.98 is properly written as

• 0.0565.

• 0.056.

• 0.05646.

• 0.06.

• 0.056462.

The symbol for the SI base unit of mass is

• kg.

• metric ton.

• mg.

• lb.

• g.

Compound 1 has a composition of 46.7 mass % of element A and 53.3 mass % of element B. A and B also form a second binary compound (compound 2). If the compositions of the two compounds are consistent with the law of multiple proportions, which of the following compositions could be that of compound 2?

• 53.3 mass % A 46.7 mass % B

• 73.3 mass % A 26.7 mass % B

• 30.4 mass % A 69.6 mass % B

• 23.4 mass % A 76.6 mass % B

• 33.3 mass % A 66.7 mass % B

Millikan's oil-drop experiment

• suggested that some oil drops carried fractional numbers of electrons.

• provided support for the nuclear model of the atom.

• established the charge on an electron.

• showed that all oil drops carried the same charge.

• suggested the presence of a neutral particle in the atom.

In the modern periodic table, the order in which the elements are placed is based on

• atomic size.

• atomic mass.

• mass number.

• chemical reactivity.

• atomic number.