Question 1

Which property of water is primarily responsible for its ability to dissolve ionic compounds such as table salt (NaCl)?

Accepted Answer

Its polarity and ability to form hydrogen bonds

Question 2

Why does ice float on liquid water?

Accepted Answer

Ice forms an open crystal structure due to hydrogen bonding, making it less dense than liquid water

Question 3

Which of the following best describes a spontaneous chemical reaction?

Accepted Answer

A reaction that proceeds on its own, with products having lower potential energy and greater disorder (entropy) than reactants

Question 4

A solution has a pH of 5. Which statement is true about this solution?

Accepted Answer

It is acidic and has a higher concentration of hydrogen ions than pure water

Question 5

Which functional group is most likely to act as a base by attracting a proton?

Accepted Answer

Amino group

Question 6

What is the main reason sweating cools the human body?

Accepted Answer

Water absorbs a large amount of energy to break hydrogen bonds during evaporation

Question 7

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

Accepted Answer

Octane ($$\mathrm{C_8H_{18}})$$

Question 8

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

Accepted Answer

Hydrolysis of polymers

Question 9

What is the role of buffers in biological systems?

Accepted Answer

Buffers minimize changes in pH and help maintain homeostasis

Question 10

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

Question 11

Which environment is thought to have contributed to chemical evolution on early Earth by providing heat and reactive metals?

Accepted Answer

Deep-sea hydrothermal vents

Question 12

What is the main difference between hydrophilic and hydrophobic molecules in terms of their interaction with water?

Accepted Answer

Hydrophilic molecules are charged or polar and interact with water's partial charges, while hydrophobic molecules are uncharged and nonpolar

Question 13

Which of the following is a correct statement about carbon in biological molecules?

Accepted Answer

Carbon forms four covalent bonds due to its four valence electrons

Question 14

Stanley Miller's experiment in 1953 demonstrated that:

Accepted Answer

Amino acids, the building blocks of proteins, can be formed from simple molecules under early Earth conditions

Question 15

Which functional group is most likely to drop a proton and act as an acid?

Accepted Answer

Carboxyl group

Question 16

Which property of water allows insects to walk on its surface?

Accepted Answer

Surface tension due to cohesion between water molecules

Question 17

What is the effect of adding a base to an aqueous solution?

Accepted Answer

It decreases the concentration of hydronium ions ($$\mathrm{H_3O^+})$$

Question 18

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 19

Which functional group is responsible for linking molecules into more-complex compounds?

Accepted Answer

Carbonyl group

Question 20

Which of the following statements about entropy is correct?

Accepted Answer

Entropy increases when products are less ordered than reactants

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

Study Guide - Practice Questions