Question 1

Which property of water allows it to moderate temperature changes within organisms and their environments?

Accepted Answer

High specific heat resulting from hydrogen bonding

Question 2

A coastal city experiences milder temperatures compared to an inland city at the same latitude. Which property of water is primarily responsible for this phenomenon?

Accepted Answer

Water's high specific heat

Question 3

Why does ice float on liquid water?

Accepted Answer

Ice is less dense than liquid water because hydrogen bonds keep water molecules farther apart in the solid state

Question 4

Which equation correctly represents the relationship between pH and hydrogen ion concentration?

Accepted Answer

$$\mathrm{pH} = -\log [\mathrm{H}^+]$$

Question 5

A solution has a hydrogen ion concentration of $$1 	imes 10$$^{-4}$$ M. What is its pH?

Accepted Answer

pH = 4

Question 6

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

Accepted Answer

Evaporation of sweat absorbs heat from the skin due to water's high heat of vaporization

Question 7

What is the role of buffers in biological systems?

Accepted Answer

Buffers maintain stable pH by absorbing excess $$\mathrm{H}^+ or$$ $$\mathrm{OH}^-$$ ions

Question 8

Which of the following is true about acids and bases in aqueous solutions?

Accepted Answer

Bases donate $$\mathrm{OH}^-$$ ions and raise the pH

Question 9

If the concentration of $$\mathrm{H}^+ in a $$solution is $$1 	imes 10$$^{-7}$$ M, what is the concentration of $$\mathrm{OH}^-$$ at 25°C?

Accepted Answer

$$1 	imes 10$$^{-7}$$ M

Question 10

Ocean acidification is primarily caused by which chemical reaction?

Accepted Answer

$$\mathrm{CO}_2 + \mathrm{H}_2\mathrm{O} \rightarrow \mathrm{H}_2\mathrm{CO}_3$$

Question 11

Which of the following is a consequence of increased ocean acidification?

Accepted Answer

Decrease in carbonate ion concentration, affecting calcification in marine organisms

Question 12

A protein has both hydrophilic and hydrophobic regions. In water, how will it likely behave?

Accepted Answer

It will form a colloid or micelle, with hydrophilic regions interacting with water

Question 13

Which of the following best describes a solution?

Accepted Answer

A homogeneous mixture of solute and solvent

Question 14

Which of the following substances is most likely to be hydrophobic?

Accepted Answer

Vegetable oil

Question 15

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

Accepted Answer

Water reaches its greatest density at $$4^\circC$$

Question 16

A buffer system in blood involves carbonic acid and bicarbonate ion. If excess $$\mathrm{H}^+ is $$present, what happens?

Accepted Answer

Bicarbonate binds with $$\mathrm{H}^+ to $$form carbonic acid

Question 17

Which of the following best explains why water is a versatile solvent?

Accepted Answer

Water's polarity allows it to form hydration shells around ions and polar molecules

Question 18

Which of the following equations represents the dissociation of carbonic acid in water?

Accepted Answer

$$\mathrm{H}_2\mathrm{CO}_3 \rightleftharpoons \mathrm{H}^+ + \mathrm{HCO}_3^-$$

Question 19

Which of the following is true regarding the product of $$[\mathrm{H}^+]$$ and $$[\mathrm{OH}^-] in $$any aqueous solution at 25°C?

Accepted Answer

$$[\mathrm{H}^+][\mathrm{OH}^-] = 1 	imes 10$$^{-14}$$

Chapter 3: Water and Life: Properties, Functions, and Importance in Biology

Study Guide - Practice Questions

Study Guide - Flashcards