Chemistry A Quiz 3 Of 3

Which of the following correctly matches a compound with its molecular geometry?

• Methane (CH4): tetrahedral

• Water (H2O): linear

• Carbon dioxide (CO ): tetrahedral 2

• Ammonia (NH3): trigonal planar

When zinc is exposed to air, zinc oxide is produced. What happens in this reaction?

• Zinc is oxidized, and oxygen is reduced.

• Zinc is reduced, and oxygen is oxidized.

• Both zinc and oxygen are oxidized.

• Both zinc and oxygen are reduced.

How many molecules are in 0.500 mole of N2O5?

• 3.01×1023 molecules

• 1.20×1023 molecules

• 6.02×1023 molecules

• 3.01×1024 molecules

Which of these statements is an accurate description of the ionization energies of elements in the periodic table?

• The ionization energy of lithium is greater than that of potassium.

• The ionization energy of iodine is greater than that of fluorine.

• The ionization energy of magnesium is greater than that of sulfur.

• The ionization energy of krypton is greater than that of neon.

Chemists can identify the composition of some unknown salts by conducting a flame test. When potassium salts are heated in a flame, a purple color is observed. This is due to the movement of electrons between energy levels. What is the electron configuration of a potassium atom at ground state?

• 1s22s22p63s23p64s1

• 1s22s22p63s23p64d1

• 1s22s22p63s23p63d1

• 1s22s22d63s23d64s1

Which product balances the chemical equation below? 3AgNO3(aq) + FeCl3(aq) → 3AgCl(s) + ______________

• Fe(NO3)3(aq)

• FeCl(aq)

• FeCl2(aq)

• FeNO3(aq)

As a distant star moves away from Earth, the light given off by the star has a measurably lower frequency. What happens to the wavelength and energy of the photons of light when the frequency becomes lower?

• The wavelength becomes longer, and the energy decreases.

• The wavelength becomes shorter, and the energy decreases.

• The wavelength becomes longer, and the energy increases.

• The wavelength becomes shorter, and the energy increases.

Which of the following includes an example of a chemical property of an element?

• Aluminum is a solid at room temperature and is a poor thermal insulator

• Sulfur is not shiny and is not malleable

• Sodium is a solid at room temperature and reacts with other elements

• Silicon is shiny and is a poor conductor of electricity

• F

• G

• H

• J

• Volume

• Mass

• Boiling Point

• Number of Moles

• Sample W

• Sample X

• Sample Y

• Sample Z

In a famous experiment conducted by Ernest Rutherford, positively charged alpha particles were scattered by a thin gold foil. Which of the following is a conclusion that resulted from this experiment?

• The nucleus is very small and the atom is mostly empty space.

• The nucleus is negatively charged.

• The atom is a dense solid and is indivisible.

• The mass is conserved when atoms react chemically.

• A heterogenous mixture

• An element

• A compound

• A homogenous mixture

What is the volume of 2.00 moles of chlorine (Cl2) at STP, to the nearest tenth of a liter? STP = Standard Temperature and Pressure

• Liquid condenses on a cold glass rod when gas from the test tube on the left is released.

• A gas probe indicates that the water in the beaker contains dissolved nitrogen and oxygen.

• A burning wood splint placed above the mouth of the test tube on the right glows brighter when some gas is released from the test tube.

• The temperature of the wire connected to the battery increases.

• Trihydrogen phosphite

• Phosphoric acid

• Phosphorous hydroxide

• Phosphorous acid

• Indium (In), because it has a slightly higher atomic mass than aluminum (Al), and tin (Sn), because it has a slightly higher atomic mass than silicon (Si)

• Cadmium (Cd), because it has chemical properties similar to those of zinc (Zn), and mercury (Hg), because it has chemical properties similar to those of arsenic (As)

• Antimony (Sb), because it has a slightly higher atomic mass than zinc (Zn), and bismuth (Bi), because it also has a higher atomic mass than zinc (Zn)

• Gallium (Ga), because it has chemical properties similar to those of aluminum (Al), and germanium (Ge), because it has chemical properties similar to those of silicon (Si)

Sodium, mercury, argon, and neon are used in the production of lamps. There are fewer safety guidelines regarding the handling of neon and argon than for mercury and sodium. Which of the following best describes the elements within the group of the periodic table that contains neon and argon gas?

• Gaseous at room temperature and highly reactive with metals

• Solid at room temperature and mildly reactive with strong acids

• Gaseous at room temperature and mostly unreactive with metals

• Solid at room temperature and mostly unreactive with strong acids

What is the percentage by mass of sodium (Na) in a formula unit of sodium hydrogen carbonate (NaHCO3)?

• 44.2%

• 37.7%

• 27.4%

• 16.7%

How many atoms are present in 179.0 g of iridium?

• 5.606×10^23 atoms

• 6.464×10^23 atoms

• 1.078 × 10^26 atoms

• 1.157×10^26 atoms

X-ray crystallography is a technique that allows scientists to determine the ionic and atomic radii of elements. Which of these statements correctly describes a trend in ionic or atomic radii in the periodic table?

• The ionic radius decreases from top to bottom in a group.

• The atomic radius increases from left to right across a period.

• The ionic radius remains constant from right to left across a period.

• The atomic radius increases from top to bottom in a group.

• A

• B

• C

• D

• It is a pure substance because solid particles cannot pass through the filter paper.

• It is a pure substance because the river water is composed only of free elements.

• It is a mixture because dissolved ions in the water pass through the filter paper.

• It is a mixture because solid particles are separated from the river water.

Which of the following best explains why CO2 gas is easily compressible but solid CO2 (dry ice) is incompressible?

• The molecules of CO2 gas are much closer together than the molecules in dry ice.

• The molecules of solid CO2 are much closer together than the molecules of CO2 gas.

• The molecules of CO2 gas are much smaller than the molecules of solid CO2.

• The molecules of CO2 gas attract one another, while the molecules of the solid CO2 repel one another.

What is the formula of the ion hydrogen sulfite, which has a charge of −1?

• SO3 −1

• SO4−1

• HSO3−1

• HSO4−1

What is the chemical formula for disulfur decafluoride?

• S10F2

• S3F9

• S2F10

• S2F8