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

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

Question 1

Which of the following statements best explains why water is an efficient solvent for biological reactions?

Accepted Answer

Water is highly polar, allowing it to form hydrogen bonds with ions and polar molecules, thus dissolving them.

Question 2

A radioactive isotope of carbon, carbon-14, is used in radiometric dating. Which of the following is true about carbon-14?

Accepted Answer

It has 6 protons and 8 neutrons in its nucleus.

Question 3

Which of the following best describes the difference between a polar covalent bond and a nonpolar covalent bond?

Accepted Answer

A polar covalent bond involves unequal sharing of electrons due to differences in electronegativity, while a nonpolar covalent bond involves equal sharing.

Question 4

Which property of water is primarily responsible for the phenomenon of surface tension?

Accepted Answer

Cohesion due to hydrogen bonding between water molecules.

Question 5

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

Accepted Answer

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

Question 6

Which of the following best explains why ice floats on liquid water?

Accepted Answer

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

Question 7

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

Accepted Answer

Amino group

Question 8

Which of the following statements about chemical reactions and energy is correct?

Accepted Answer

Exothermic reactions release thermal energy, while endothermic reactions absorb it.

Question 9

Which of the following is a consequence of the second law of thermodynamics in biological systems?

Accepted Answer

Physical and chemical processes proceed in the direction of increased entropy and/or lower potential energy.

Question 10

A molecule of methane ($$CH_4) $$has which of the following molecular geometries?

Accepted Answer

Tetrahedral

Question 11

Which of the following best describes the process of polymerization in biological macromolecules?

Accepted Answer

Polymerization occurs via condensation (dehydration) reactions, which remove water to form bonds.

Question 12

Which of the following statements about the Miller-Urey experiment is correct?

Accepted Answer

It showed that amino acids and other organic molecules could be synthesized from simple gases with energy input.

Question 13

Which of the following best explains why carbon is the backbone of biological macromolecules?

Accepted Answer

Carbon can form up to four covalent bonds, allowing for a variety of stable, complex structures.

Question 14

Which of the following is true about the relationship between electronegativity and bond type?

Accepted Answer

A small or no difference in electronegativity results in a nonpolar covalent bond.

Question 15

Which of the following best describes a buffer in biological systems?

Accepted Answer

A buffer minimizes changes in pH by accepting or donating protons.

Question 16

If a solution changes from pH 6 to pH 4, how does the hydrogen ion concentration change?

Accepted Answer

It increases by a factor of 100.

Question 17

Which of the following is a real-world example of an exothermic reaction relevant to biology?

Accepted Answer

Combustion of glucose during cellular respiration

Question 18

Which of the following statements about van der Waals interactions is correct?

Accepted Answer

They stabilize clusters of hydrophobic molecules in water.

Question 19

Which of the following best describes the role of functional groups in organic molecules?

Accepted Answer

Functional groups define the chemical reactivity and properties of organic molecules.

Water and Carbon: The Chemical Basis of Life (General Biology Study Notes)

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드