Question 1

Which property of water is primarily responsible for the upward movement of water through the vessels of a plant against gravity?

Accepted Answer

Cohesive behavior

Question 2

Why does ice float on liquid water?

Accepted Answer

Hydrogen bonds in ice are more ordered, causing the molecules to be farther apart.

Question 3

A solution has a pH of 5. What is the concentration of hydrogen ions $$[H^+] in $$this solution?

Accepted Answer

$$[H^+] = 10$$^{-5}$$ \, M$$

Question 4

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

Accepted Answer

Water's polarity allows it to surround and separate ions and polar molecules.

Question 5

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

Accepted Answer

It increases by a factor of 100.

Question 6

Which of the following is a hydrophobic substance?

Accepted Answer

Oil

Question 7

A buffer solution is important in biological systems because it:

Accepted Answer

Minimizes changes in pH by accepting or donating $$H^+$$ ions.

Question 8

Given the equation $$[H^+][OH^-] = 10$$^{-14}$$ at 25$$^\circ C$$, what is the $$[OH^-]$$ in a solution with $$[H^+] = $$10^{-3}$$ \, M$$?

Accepted Answer

$$[OH^-] = 10$$^{-11}$$ \, M$$

Question 9

Which of the following statements about acids and bases is correct?

Accepted Answer

An acid increases the $$[H^+] of a $$solution.

Question 10

A solution has a pH of 9. What is its pOH?

Accepted Answer

pOH = 5

Question 11

Which of the following best describes the relationship between $$pH$$ and $$[H^+]$$?

Accepted Answer

$$pH = -\log [H^+]$$

Question 12

Which property of water allows it to moderate Earth's climate by absorbing and releasing heat with only slight changes in its own temperature?

Accepted Answer

High specific heat

Question 13

Which of the following is true about the dissociation of water?

Accepted Answer

It produces equal numbers of $$H^+$$ and $$OH^-$$ ions.

Question 14

A patient’s blood pH drops from 7.4 to 7.1 due to a medical condition. What is the best explanation for why this is dangerous?

Accepted Answer

Small changes in pH can disrupt cellular processes by altering protein structure and enzyme activity.

Question 15

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

Accepted Answer

Evaporation of sweat absorbs heat due to water's high heat of vaporization.

Question 16

Which of the following is NOT a property of water that contributes to Earth's suitability for life?

Accepted Answer

Low heat of vaporization

Question 17

If a solution has $$[OH^-] = 10$$^{-12}$$ \, M$$, what is its pH?

Accepted Answer

pH = 2

Question 18

Which of the following scenarios best illustrates the action of a buffer in human blood?

Accepted Answer

A buffer accepts excess $$H^+$$ ions when blood becomes too acidic, minimizing pH change.

Question 19

Which of the following best describes a hydrophilic substance?

Accepted Answer

A substance that has an affinity for water

Question 20

Which of the following is a real-life example of water’s versatility as a solvent?

Accepted Answer

Salt dissolving in ocean water

Water and Life: Properties, Acidity, and Biological Importance

Study Guide - Practice Questions