Question 1

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

Accepted Answer

Hydrogen bonds form a relatively open crystal structure in ice, making it less dense than liquid water.

Question 2

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

Accepted Answer

Water's bent shape and overall polarity allow it to form hydrogen bonds with charged or polar solutes.

Question 3

A scientist adds a base to a solution. What happens to the concentration of hydronium ions ($$H_3O^+) $$and the pH?

Accepted Answer

Hydronium ion concentration decreases and pH increases.

Question 4

Which of the following is a direct result of water's high specific heat?

Accepted Answer

Water resists rapid temperature changes, helping organisms maintain stable internal temperatures.

Question 5

Which functional group acts as a base by attracting protons?

Accepted Answer

Amino group

Question 6

What is the main reason that hydrophobic molecules do not dissolve in water?

Accepted Answer

They are nonpolar and do not interact favorably with water's partial charges.

Question 7

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

Accepted Answer

A reaction that joins monomers to form polymers, releasing a water molecule.

Question 8

Why is sweating an effective way for humans to cool off?

Accepted Answer

Water has a high heat of vaporization, so evaporation removes a large amount of heat from the body.

Question 9

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 10

Which of the following is true about the pH scale?

Accepted Answer

A solution with pH 5 has ten times more hydrogen ions than a solution with pH 6.

Question 11

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

Accepted Answer

Adhesion between water molecules and glass

Question 12

Which of the following best explains why buffers are important in biological systems?

Accepted Answer

They minimize changes in pH, helping maintain homeostasis.

Question 13

Which of the following is a characteristic of a spontaneous chemical reaction?

Accepted Answer

The products have lower potential energy and are less ordered than the reactants.

Question 14

Which experiment provided evidence that complex organic molecules could form under early Earth conditions?

Accepted Answer

Miller's spark-discharge experiment

Question 15

Which of the following statements about carbon is FALSE?

Accepted Answer

Carbon can only form single bonds with other atoms.

Question 16

Which functional group is most likely to form disulfide bonds in proteins?

Accepted Answer

Sulfhydryl group

Question 17

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

Accepted Answer

$$[H^+] = 1 	imes 10$$^{-4}$$ \ \mathrm{M}$$

Question 18

Which of the following best describes van der Waals interactions?

Accepted Answer

Weak attractions that stabilize clusters of hydrophobic molecules

Question 19

Which process increases entropy and is energetically favorable in aqueous solutions?

Accepted Answer

Hydrolysis of polymers into monomers

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

Study Guide - Practice Questions