Question 1

Which of the following statements best explains why water is an efficient solvent for ionic and polar molecules?

Accepted Answer

Water molecules have partial charges that can surround and stabilize ions and polar molecules.

Question 2

A neutral atom of oxygen has an atomic number of 8 and a mass number of 16. How many protons, neutrons, and electrons does it contain?

Accepted Answer

8 protons, 8 neutrons, 8 electrons

Question 3

Which property of water allows aquatic life to survive in cold climates during winter?

Accepted Answer

Expansion upon freezing

Question 4

What type of chemical bond is present in sodium chloride (NaCl), and what is the nature of the charges on the atoms?

Accepted Answer

Ionic bond; sodium has a positive charge and chlorine has a negative charge

Question 5

Which functional group acts as a base and tends to attract a proton?

Accepted Answer

Amino group

Question 6

Why does ice float on water?

Accepted Answer

Ice is less dense than liquid water because it forms an open crystal structure.

Question 7

Which equation correctly expresses the relationship between pH and proton concentration $$[H^+]$$?

Accepted Answer

$$pH = -\log [H^+]$$

Question 8

Which of the following molecules would be least likely to dissolve in water?

Accepted Answer

Methane

Question 9

What is the main reason that morphine and endorphins can bind to the same receptors in the brain?

Accepted Answer

They have similar molecular shapes.

Question 10

Which of the following best describes a condensation (dehydration) reaction?

Accepted Answer

A reaction that joins monomers into polymers and releases a water molecule.

Question 11

Which property of water is responsible for the phenomenon where insects can walk on the surface of a pond?

Accepted Answer

Surface tension due to cohesion

Question 12

Which of the following statements about covalent bonds is correct?

Accepted Answer

Covalent bonds involve the sharing of a pair of valence electrons between two atoms.

Question 13

Which functional group is most likely to act as an acid by donating a proton in solution?

Accepted Answer

Carboxyl group

Question 14

What is the main difference between polar and nonpolar covalent bonds?

Accepted Answer

Polar covalent bonds involve unequal sharing of electrons due to differences in electronegativity; nonpolar covalent bonds involve equal sharing.

Question 15

Which of the following scenarios best illustrates water's high specific heat?

Accepted Answer

The sand at the beach burns your feet, but the ocean water is relatively cool.

Question 16

Which of the following is true about the pH of a solution?

Accepted Answer

A solution with $$[H^+] = 10$$^{-7}$$ M has a pH of 7.

Question 17

Which functional group is responsible for linking together via disulfide bonds in proteins?

Accepted Answer

Sulfhydryl group

Question 18

Which of the following molecules is nonpolar and would not have any partial charges?

Accepted Answer

Methane ($$CH_4)$$

Question 19

What is the result of a hydrolysis reaction in biological macromolecules?

Accepted Answer

Polymers are broken apart by the addition of water.

Question 20

Which property of water explains why powdered beverages like lemonade mix well with water?

Accepted Answer

Efficient solvent (hydrophilic property)

The Chemistry of Life: Foundations for Biology

Study Guide - Practice Questions