Question 1

Which of the following best explains why water is a polar molecule?

Accepted Answer

Oxygen is more electronegative than hydrogen, causing unequal sharing of electrons.

Question 2

A spider is able to walk on water due to which property of water?

Accepted Answer

Cohesion, resulting in surface tension

Question 3

Which equation correctly represents the relationship for Gibbs free energy?

Accepted Answer

$$\Delta G = \Delta H - T\Delta S$$

Question 4

Which of the following statements about the first law of thermodynamics is correct?

Accepted Answer

Energy cannot be created or destroyed, only transformed.

Question 5

A reaction has $$\Delta G \u003c 0. $$Which of the following is true?

Accepted Answer

The reaction is exergonic and releases energy.

Question 6

Which property of water allows it to dissolve ionic compounds like NaCl?

Accepted Answer

Polarity, allowing formation of hydration shells around ions

Question 7

What is the main function of a buffer in biological systems?

Accepted Answer

To maintain a stable pH by absorbing or releasing H+ ions

Question 8

Which of the following best describes what happens during oxidation in a redox reaction?

Accepted Answer

A molecule loses electrons

Question 9

Why does ice float on liquid water?

Accepted Answer

Hydrogen bonds in ice keep water molecules farther apart, making it less dense.

Question 10

Which of the following would increase the rate of a chemical reaction in a cell?

Accepted Answer

Adding a catalyst such as an enzyme

Question 11

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

Accepted Answer

$$[H^+] = 10$$^{-4}$$ M

Question 12

Which of the following best explains why sweating cools the body?

Accepted Answer

Evaporation of water requires energy, which is absorbed from the skin.

Question 13

Which of the following is true about the effect of enzymes on chemical reactions?

Accepted Answer

Enzymes lower the activation energy but do not change $$\Delta G.$$

Question 14

Which of the following is an example of potential energy being converted to kinetic energy?

Accepted Answer

A diver jumping off a platform into the water.

Question 15

Which of the following best describes a nonpolar covalent bond?

Accepted Answer

A bond where electrons are shared equally between identical atoms.

Question 16

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

Accepted Answer

It increases by 100 times.

Question 17

Which property of water is most responsible for capillary action in plants?

Accepted Answer

Cohesion and adhesion

Question 18

Which of the following is a correct statement about chemical equilibrium?

Accepted Answer

At equilibrium, the rate of the forward reaction equals the rate of the reverse reaction.

Question 19

Which of the following best describes the role of bicarbonate ($$HCO_3$$^-$$) in human blood?

Accepted Answer

It acts as a buffer to maintain pH homeostasis.

Question 20

Which of the following scenarios best illustrates the second law of thermodynamics?

Accepted Answer

A hot cup of coffee cooling down to room temperature.

Chemical Reactions, Water, and pH Chemistry in Biology

스터디 가이드 - 연습 문제