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

Question 1

Which property of water allows insects such as water striders to walk on the surface of a pond without sinking?

Accepted Answer

Cohesion due to hydrogen bonding

Question 2

Why does ice float on liquid water?

Accepted Answer

Ice is less dense than liquid water because hydrogen bonds keep water molecules further apart in solid form

Question 3

Which of the following best explains why water has a high specific heat?

Accepted Answer

Hydrogen bonds between water molecules require significant energy to break

Question 4

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}$$ M

Question 5

If the cytosol of a cell is at pH 7 and the lysosome is at pH 5, what is the difference in hydrogen ion concentration between the two compartments?

Accepted Answer

The lysosome has 100 times more $$H^+$$ than the cytosol

Question 6

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

Accepted Answer

A buffer minimizes changes in pH by accepting or donating $$H^+$$ ions

Question 7

Which property of water is most important for the transport of water from roots to leaves in plants?

Accepted Answer

Cohesion and adhesion

Question 8

A hydrophilic substance will:

Accepted Answer

Readily dissolve in water due to its polar nature

Question 9

Which of the following is true about the pH scale?

Accepted Answer

A decrease in pH by 1 unit means the $$[H^+]$$ increases by 10 times

Question 10

Which chemical bond is responsible for water's cohesion and adhesion properties?

Accepted Answer

Hydrogen bonds

Question 11

A solution is made by dissolving salt in water. In this solution, water acts as the:

Accepted Answer

Solvent

Question 12

Which of the following best explains why water is an excellent solvent for many biological molecules?

Accepted Answer

Water is polar and can form hydration shells around ions and polar molecules

Question 13

Which of the following would most likely be insoluble in water?

Accepted Answer

A hydrophobic lipid

Question 14

Which property of water helps moderate Earth's climate by absorbing heat from warmer air and releasing it to cooler air?

Accepted Answer

Water's high specific heat

Question 15

Which of the following is an example of water's adhesion?

Accepted Answer

Water molecules sticking to the walls of plant vessels

Question 16

What does it mean for a protein to be soluble in water?

Accepted Answer

The protein can interact with water molecules via polar or charged side chains

Question 17

Which of the following best describes a hydration shell?

Accepted Answer

A layer of water molecules surrounding a dissolved ion or polar molecule

Question 18

If a solution has a pH of 2, how does its hydrogen ion concentration compare to a solution with pH 5?

Accepted Answer

It has 1000 times more $$H^+$$

Question 19

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

Accepted Answer

Water's inability to dissolve polar substances

Water and pH: Properties, Biological Importance, and Chemical Principles

Study Guide - Practice Questions