Question 1

Table salt is formed when

Accepted Answer

A)  chlorine gives an electron to sodium.
B)  a hydrogen bond forms between sodium and chlorine.
C)  sodium and chlorine share electrons to form a bond.
D)  sodium donates its single outer electron to chlorine. D

Question 2

A single water molecule (H-O-H)is held together by

Accepted Answer

A)  a single covalent bond.
B)  a double covalent bond.
C)  two polar covalent bonds.
D)  hydrogen bonds. C

Question 3

Which of the following hypotheses would be supported if liquid water were found on Mars and contained evidence of bacteria-like organisms?

Accepted Answer

A)  Life must evolve in the presence of oxygen.
B)  The chemical evolution of life is possible.
C)  Life on Earth must have originated on Mars.
D)  Life is guided by intelligent design. B

Question 4

Which of the following statements about pH is true?

Accepted Answer

A)  The pH scale is a measure of oxygen ion concentration.
B)  A single unit change on the pH scale is equivalent to a 1% change in hydrogen ion concentration.
C)  An increase in hydrogen ion concentration means a decrease in pH scale units.
D)  Basic pH levels are less than 7.

Question 5

Radioactive isotopes

Accepted Answer

A)  are frequently added to foods as nutritional supplements.
B)  can be used in conjunction with PET scans to diagnose diseases.
C)  do not occur naturally.
D)  are never incorporated into organic compounds.

Question 6

Which of the following is another term used for atomic mass?

Accepted Answer

A)  darwin
B)  mendel
C)  dalton
D)  calvin

Question 7

In ocean acidification, dissolving CO₂ gas ________ the pH of the ocean.

Accepted Answer

A)  lowers
B)  does not affect
C)  raises
D)  triples

Question 8

The figure below shows five water molecules. The hydrogen bonds shown in this figure are each

Accepted Answer

A)  between two hydrogen atoms.
B)  between an oxygen and a hydrogen atom of the same water molecule.
C)  between an oxygen and a hydrogen atom of different water molecules.
D)  between two atoms with the same charge.

Question 9

Which of the following particles are found in the nucleus of an atom?

Accepted Answer

A)  protons and neutrons
B)  protons and electrons
C)  only protons
D)  only electrons

Question 10

A buffer

Accepted Answer

A)  is an acid that is used to offset overly basic conditions in the body.
B)  is a base that is used to offset overly acidic conditions in the body.
C)  donates H⁺ ions when conditions become too basic and accepts H⁺ ions when conditions become too acidic.
D)  donates OH⁻ ions when conditions become too basic and accepts OH⁻ ions when conditions become too acidic.

Question 11

Which of the following statements regarding chemical reactions is false?

Accepted Answer

A)  Chemical reactions involve the making and breaking of chemical bonds.
B)  Some chemical reactions create electrons; others destroy them.
C)  The reactants contain the same number of atoms as the products.
D)  Although the atoms of a reaction's reactants and products are identical to each other, their molecular formulas differ.

Question 12

Below is the structure of octane, the major component of gasoline. What type(s)of bond is (are)found in a molecule of octane?

Accepted Answer

A)  only nonpolar covalent bonds
B)  only polar covalent bonds
C)  hydrogen bonds and polar covalent bonds
D)  ionic bonds and nonpolar covalent bonds

Question 13

Which of the following statements regarding the oxygen atom of a water molecule is true?

Accepted Answer

A)  Oxygen is more positively charged than the hydrogen atoms.
B)  Oxygen attracts electrons less strongly than the hydrogen atoms.
C)  Oxygen is more electronegative than the hydrogen atoms.
D)  Oxygen is attracted to the negatively charged atoms of other molecules.

Question 14

You hypothesize that a tablet of PEPCID AC can neutralize more stomach acid than a tablet of Alka-Seltzer. If you placed a tablet of each antacid in a beaker of acid at an initial pH of 2, which of the following experimental results would support your hypothesis?

Accepted Answer

A)  After 1 hour, the pH of the solution in the PEPCID AC beaker was 9.2 and the pH of the solution in the Alka-Seltzer beaker was 8.3.
B)  After 1 hour, the pH of the solution in the PEPCID AC beaker was 7.9 and the pH of the solution in the Alka-Seltzer beaker was 9.6.
C)  After 1 hour, the pH of the solution in the PEPCID AC beaker was equal to that of the pH of the solution in the Alka-Seltzer beaker.
D)  It took 3 minutes for the PEPCID AC tablet to fully dissolve and it took 5 minutes for the Alka-Seltzer tablet to fully dissolve.

Question 15

The sodium atom contains 11 electrons, 11 protons, and 12 neutrons. What is the mass number of sodium?

Accepted Answer

A)  11
B)  22
C)  23
D)  34

Question 16

Which of the following best describes the atomic number of an atom?

Accepted Answer

A)  the number of protons in the atom
B)  the number of electrons in the atom
C)  the number of neutrons in the atom
D)  the number of protons, electrons, and neutrons in the atom

Question 17

A hydrogen atom has one electron. How many covalent bonds can hydrogen form?

Accepted Answer

A)  one
B)  two
C)  four
D)  none

Question 18

You want to design an experiment to compare the effectiveness of Pepcid AC tablets and Alka-Seltzer tablets. Which of the following facts would be least likely to complicate your experiment and the analysis of your results?

Accepted Answer

A)  PEPCID AC and Alka-Seltzer tablets contain different concentrations of the antacid drug.
B)  PEPCID AC and Alka-Seltzer tablets contain different ingredients.
C)  The recommended dosage for PEPCID AC and Alka-Seltzer tablets is different.
D)  PEPCID AC and Alka-Seltzer tablets are sold in different countries throughout the world.

Question 19

A radioactive isotope is an isotope that

Accepted Answer

A)  is stable.
B)  decays.
C)  has more protons than the common variant of the element.
D)  has the same atomic mass but a different atomic number than the common variant of the element.

Question 20

Which of the following statements regarding matter is false?

Accepted Answer

A)  All life is composed of matter.
B)  All matter has mass.
C)  All matter is composed of elements.
D)  All matter exists in the form of compounds.

Exam 2: The Chemical Basis of Life