Question 1

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

Accepted Answer

Hydrogen bonds in ice create an open crystal structure, making ice 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’s polarity allows it to form hydrogen bonds with ions and polar molecules, keeping them in solution.

Question 3

A scientist adds a strong acid to a solution, causing the pH to drop from 7 to 4. By what factor has the hydrogen ion concentration increased?

Accepted Answer

$$1000$$

Question 4

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

Accepted Answer

Amino group

Question 5

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

Accepted Answer

Evaporation of sweat absorbs a large amount of energy due to water’s high heat of vaporization.

Question 6

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

Accepted Answer

Nonpolar molecules cannot form hydrogen bonds with water, so they cluster together through hydrophobic interactions.

Question 7

Which of the following statements about chemical evolution is supported by Stanley Miller’s experiment?

Accepted Answer

Simple molecules with high free energy can form complex organic molecules when exposed to kinetic energy.

Question 8

Which of the following is a direct consequence of water’s high specific heat?

Accepted Answer

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

Question 9

Which process is responsible for breaking polymers into monomers, and what is the effect on entropy?

Accepted Answer

Hydrolysis; increases entropy

Question 10

A solution has a pH of 9. Which of the following statements is true?

Accepted Answer

The solution is basic and has a low concentration of hydrogen ions.

Question 11

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

Accepted Answer

Adhesion between water and glass

Question 12

Which of the following best describes the role of buffers in biological systems?

Accepted Answer

Buffers minimize changes in pH, helping maintain homeostasis.

Question 13

Which of the following statements about carbon is correct?

Accepted Answer

Carbon forms four covalent bonds, allowing for a variety of molecular shapes.

Question 14

Which of the following reactions is most likely to occur spontaneously?

Accepted Answer

A reaction where products have lower potential energy and are less ordered than reactants.

Question 15

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

Accepted Answer

Sulfhydryl group

Question 16

Which of the following best explains why water has a high surface tension?

Accepted Answer

Cohesion due to hydrogen bonding between water molecules at the surface.

Question 17

Which of the following is an example of a condensation (dehydration) reaction?

Accepted Answer

Linking two monosaccharides to form a disaccharide and releasing a water molecule.

Question 18

Which of the following statements about hydrophobic interactions is correct?

Accepted Answer

Hydrophobic molecules cluster together in water, stabilized by van der Waals interactions.

Question 19

Which of the following best describes the difference between adhesion and cohesion in water?

Accepted Answer

Cohesion is the attraction between water molecules; adhesion is the attraction between water and other substances.

Question 20

Which of the following is true about the formation of polymers from monomers?

Accepted Answer

Polymerization occurs via condensation reactions, which release water.

Water and Carbon: The Chemical Basis of Life – Study Notes

Study Guide - Practice Questions