Q: A solution has a hydrogen ion concentration of $$1 \times 10$$^{-5}$$ M. What is its pH?

$$pH = -\log(1 \times 10$$^{-5}$$) = 5$$

Question 1

Which property of water allows a water strider 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, and what is the biological significance of this property?

Accepted Answer

Ice is less dense than liquid water, preventing bodies of water from freezing solid and allowing life to persist underneath.

Question 3

A solution has a hydrogen ion concentration of $$1 	imes 10$$^{-5}$$ M. What is its pH?

Accepted Answer

$$pH = -\log(1 	imes 10$$^{-5}$$) = 5$$

Question 4

Which of the following best explains why water is an excellent solvent for ionic compounds?

Accepted Answer

Water molecules form hydration shells around ions due to their polarity.

Question 5

What happens to the pH of ocean water as atmospheric $$CO_2$$ increases, and what is the consequence for marine life?

Accepted Answer

pH decreases, making the water more acidic and threatening organisms like corals.

Question 6

Which statement correctly describes the difference between hydrophilic and hydrophobic substances?

Accepted Answer

Hydrophilic substances dissolve in water due to their polarity, while hydrophobic substances do not dissolve because they are nonpolar.

Question 7

A plant relies on both cohesion and adhesion to transport water from its roots to its leaves. Which of the following best describes the roles of these properties?

Accepted Answer

Cohesion holds water molecules together, while adhesion helps water stick to the walls of xylem vessels.

Question 8

If the hydrogen ion concentration in a solution changes from $$1 	imes 10$$^{-7}$$ M to 1$$ 	imes $$10^{-5} M$$, what happens to the pH and how does this affect the solution?

Accepted Answer

The pH decreases from 7 to 5, making the solution more acidic.

Question 9

Which of the following best explains why coastal cities tend to have milder climates than inland cities at the same latitude?

Accepted Answer

Water has a high specific heat, which buffers temperature changes.

Question 10

Which of the following equations correctly defines pH?

Accepted Answer

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

Question 11

A scientist adds a nonpolar oil to a beaker of water. What will most likely happen and why?

Accepted Answer

The oil will not dissolve because it is hydrophobic and nonpolar.

Question 12

Which of the following is a direct result of water's ability to form hydrogen bonds?

Accepted Answer

Water has a high surface tension.

Question 13

What is the effect of ocean acidification on calcium carbonate ($$CaCO_3) $$formation in marine organisms?

Accepted Answer

It decreases $$CaCO_3$$ formation, weakening shells and skeletons.

Question 14

Which of the following best describes the sharing of electrons in a water molecule?

Accepted Answer

Electrons are shared unequally, with oxygen being more electronegative.

Question 15

A patient’s blood pH drops from 7.4 to 7.0. What does this indicate about the hydrogen ion concentration?

Accepted Answer

The hydrogen ion concentration has increased, making the blood more acidic.

Question 16

Which process describes the movement of a hydrogen atom from one water molecule to another, resulting in the formation of hydronium and hydroxide ions?

Accepted Answer

Dissociation of water

Question 17

Why is even a slight change in pH harmful to living cells?

Accepted Answer

It can alter the structure and function of biological molecules, affecting cellular processes.

Question 18

Which of the following best explains why water moderates Earth's climate?

Accepted Answer

Water absorbs and releases heat slowly due to its high specific heat.

Question 19

Which of the following is NOT a property of water that facilitates life on Earth?

Accepted Answer

Low heat of vaporization

Water and Life: Properties, Structure, and Biological Importance

Study Guide - Practice Questions

Study Guide - Flashcards