Q: A scientist is studying a solution with a pH of 4. What is the concentration of hydrogen ions $$[H^+] in $$this solution?

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

Question 1

Which property of water is primarily responsible for the upward movement of water in plants against gravity?

Accepted Answer

Cohesion due to hydrogen bonding

Question 2

A scientist is studying a solution with a pH of 4. What is the concentration of hydrogen ions $$[H^+] in $$this solution?

Accepted Answer

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

Question 3

Why does ice float on liquid water?

Accepted Answer

Hydrogen bonds in ice are more 'ordered,' making it less dense than liquid water.

Question 4

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

Accepted Answer

Hydrogen bonds between water molecules absorb heat when they break and release heat when they form.

Question 5

A solution is made by dissolving 18 g of glucose ($$C_6H_{12}O_6$; molecular mass = 180 g/mol) in enough water to make 1 L of solution. What is the molarity of the solution?

Accepted Answer

$$0.1 \ \mathrm{M}$$

Question 6

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

Accepted Answer

A base reduces the concentration of $$H^+ in a $$solution.

Question 7

If the pH of a solution changes from 7 to 5, what happens to the hydrogen ion concentration?

Accepted Answer

It increases by 100-fold.

Question 8

Which of the following best describes a hydrophobic substance?

Accepted Answer

It does not have an affinity for water because it contains relatively nonpolar bonds.

Question 9

A marine biologist observes that coral reefs are declining in areas with increased atmospheric $$CO_2. $$Which process best explains this phenomenon?

Accepted Answer

Ocean acidification reduces carbonate ion concentration, hindering calcification.

Question 10

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

Accepted Answer

High reactivity with nonpolar molecules

Question 11

A buffer solution contains a weak acid and its corresponding base. What is the primary function of this buffer in biological systems?

Accepted Answer

To minimize changes in $$[H^+]$$ and $$[OH^-]$$ concentrations

Question 12

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

Accepted Answer

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

Question 13

A solution contains $$[H^+] = 1 	imes 10$$^{-9}$$ \ \mathrm{M}. $$What is the pH of this solution?

Accepted Answer

pH = 9

Question 14

Which of the following scenarios demonstrates the concept of adhesion?

Accepted Answer

Water molecules sticking to the walls of plant vessels

Question 15

Which of the following best describes the relationship between temperature and thermal energy?

Accepted Answer

Temperature represents the average kinetic energy, while thermal energy is the total kinetic energy.

Question 16

A researcher adds a strong acid to pure water at 25°C, increasing $$[H^+] to$$ $$1 	imes 10$$^{-3}$$ \ \mathrm{M}. $$What is the new pH?

Accepted Answer

pH = 3

Question 17

Which of the following is a real-world consequence of water's high surface tension?

Accepted Answer

Small insects can walk on the surface of a pond without sinking.

Question 18

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

Accepted Answer

Water's polarity allows it to form hydration shells around ions.

Question 19

If a solution has a pH of 12, which of the following statements is true?

Accepted Answer

The solution is basic and has a low $$[H^+]$$ concentration.

Question 20

Which of the following best describes the process of ocean acidification?

Accepted Answer

Increased atmospheric $$CO_2$$ dissolves in seawater, forming carbonic acid and lowering ocean pH.

Chapter 3: Water and Life – Study Notes for General Biology

Study Guide - Practice Questions

Study Guide - Flashcards