Question 1

Which property of water explains why ice floats on liquid water?

Accepted Answer

Water forms a relatively open crystal structure as it freezes, making it less dense than liquid water.

Question 2

Which of the following best describes why water is an excellent solvent for ionic and polar substances?

Accepted Answer

Water molecules have partial charges that interact with charged or polar solutes, forming hydrogen bonds.

Question 3

A solution has a pH of 4. What is the concentration of hydrogen ions $$[H^+] in $$this solution?

Accepted Answer

$$1 	imes 10$$^{-4}$$~M$$

Question 4

Which of the following functional groups acts as a base by attracting protons?

Accepted Answer

Amino group

Question 5

Why does sweating cool you down on a hot day?

Accepted Answer

Sweat absorbs heat as it evaporates because water has a high heat of vaporization.

Question 6

Which of the following statements about chemical evolution is correct?

Accepted Answer

It refers to the formation of increasingly complex carbon-containing substances that eventually led to self-replicating molecules.

Question 7

Which property of water is primarily responsible for the formation of a meniscus in a glass tube?

Accepted Answer

Adhesion between water molecules and the glass surface

Question 8

Which of the following best explains why nonpolar molecules do not dissolve in water?

Accepted Answer

Nonpolar molecules lack charges and cannot form hydrogen bonds with water.

Question 9

Which of the following is a correct statement about spontaneous chemical reactions?

Accepted Answer

They occur when products are less ordered and have lower potential energy than reactants.

Question 10

Which experiment provided evidence that complex organic molecules could be synthesized from simple molecules under early Earth conditions?

Accepted Answer

Miller's spark-discharge experiment

Question 11

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

Accepted Answer

A reaction in which two monomers are joined together, releasing a molecule of water.

Question 12

Which of the following functional groups is responsible for linking together via disulfide bonds?

Accepted Answer

Sulfhydryl group

Question 13

A buffer is important in biological systems because it:

Accepted Answer

Maintains relatively constant pH by minimizing changes in proton concentration.

Question 14

Which of the following is true about the structure of water?

Accepted Answer

Water has a bent shape and is highly polar.

Question 15

Which of the following best explains why water has a high specific heat?

Accepted Answer

Many hydrogen bonds must be broken for water molecules to move faster, requiring more energy.

Question 16

Which of the following is a property of hydrophobic molecules?

Accepted Answer

They are uncharged and nonpolar, and interact with each other via van der Waals interactions.

Question 17

Which of the following statements about organic compounds is correct?

Accepted Answer

Organic compounds are defined as molecules that contain carbon bonded to other elements.

Question 18

Which of the following best describes the role of entropy in spontaneous chemical reactions?

Accepted Answer

Spontaneous reactions are favored when entropy increases.

Question 19

Which of the following is a correct statement about the pH scale?

Accepted Answer

A solution with pH 7 is neutral, which is typical for the inside of living cells.

Water and Carbon: The Chemical Basis of Life (Chapter 2 Study Notes)

Study Guide - Practice Questions