Q: A solution is made by dissolving 1 mole of ethyl alcohol in enough water to make 1 liter of solution. What is the molarity ($$M) of $$ethyl alcohol in this solution?

$$M = \frac{1\ \text{mol}}{1\ \text{L}}$$

Q: What is the product of the dissociation of water in pure water?

$$\text{H}_2\text{O} \rightarrow \text{H}^+ + \text{OH}^-$$

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

Acids increase the concentration of $$\text{H}^+ in a $$solution.

Q: Which of the following best explains how buffers help maintain pH stability in biological systems?

Buffers absorb excess $$\text{H}^+ or$$ $$\text{OH}^-$$ ions, minimizing changes in pH.

Q: Which of the following best describes the relationship between $$[\text{H}^+]$$ and pH?

As $$[\text{H}^+]$$ increases, pH decreases.

Question 1

Which of the following best explains why water molecules are able to form hydrogen bonds with each other?

Accepted Answer

Water molecules have polar covalent bonds, resulting in partial positive and negative charges.

Question 2

Which property of water allows it to move upward from the roots to the leaves of a tree?

Accepted Answer

Cohesion and adhesion

Question 3

A solution is made by dissolving 1 mole of ethyl alcohol in enough water to make 1 liter of solution. What is the molarity ($$M) of $$ethyl alcohol in this solution?

Accepted Answer

$$M = \frac{1\ 	ext{mol}}{1\ 	ext{L}}$$

Question 4

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

Accepted Answer

Low surface tension

Question 5

Which statement correctly distinguishes between a solute, a solvent, and a solution?

Accepted Answer

A solvent is the substance in which the solute is dissolved to form a solution.

Question 6

Which of the following best describes hydrophobic substances?

Accepted Answer

They repel water and do not dissolve easily in aqueous solutions.

Question 7

What is the product of the dissociation of water in pure water?

Accepted Answer

$$	ext{H}_2	ext{O} ightarrow 	ext{H}^+ + 	ext{OH}^-$$

Question 8

If the concentration of hydrogen ions ($$[	ext{H}^+]) in a $$solution is $$1 	imes 10$$^{-5}$$ M, what is the pH of the solution?

Accepted Answer

$$pH = 5$$

Question 9

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

Accepted Answer

Acids increase the concentration of $$	ext{H}^+ in a $$solution.

Question 10

Which of the following best explains how buffers help maintain pH stability in biological systems?

Accepted Answer

Buffers absorb excess $$	ext{H}^+ or$$ $$	ext{OH}^-$$ ions, minimizing changes in pH.

Question 11

A solution has a pH of 3. Compared to pure water, how much higher is its hydrogen ion concentration?

Accepted Answer

1,000 times higher

Question 12

Which of the following scenarios best illustrates the concept of adhesion?

Accepted Answer

Water climbing up the walls of a glass tube.

Question 13

Which of the following would most likely increase the solubility of a hydrophilic substance in water?

Accepted Answer

Increasing the temperature of the water.

Question 14

If a solution has a hydroxide ion concentration $$[	ext{OH}^-] of$$ $$1 	imes 10$$^{-7}$$ M, what is its pOH?

Accepted Answer

$$pOH = 7$$

Question 15

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

Accepted Answer

As $$[	ext{H}^+]$$ increases, pH decreases.

Question 16

Which of the following is a real-world example of water's ability to moderate temperature?

Accepted Answer

Sweating cools the body as water evaporates from the skin.

Question 17

Which of the following best explains why ice floats on liquid water?

Accepted Answer

Ice is less dense than liquid water because hydrogen bonds keep water molecules farther apart.

Question 18

Which of the following would happen if the pH of a lake dropped from 7 to 5?

Accepted Answer

The concentration of $$[	ext{H}^+]$$ would increase by 100 times.

Question 19

Which of the following is the correct formula for calculating pH?

Accepted Answer

$$pH = -\log_{10}[	ext{H}^+]$$

Question 20

Which of the following best describes the role of water as a universal solvent?

Accepted Answer

Water can dissolve many ionic and polar substances due to its polarity.

Chapter 3: Water and Life – Key Concepts and Properties

Guida di studio - Domande di pratica

Study guide - Flashcard