Q: If the concentration of $$\mathrm{OH}^- in a $$solution is $$1 \times 10$$^{-6}$$\ \mathrm{M}$$, what is the concentration of $$\mathrm{H}^+ at$$ $$25^\circC$$, given $$[\mathrm{H}^+][\mathrm{OH}^-] = 1 \times 10$$^{-14}$$?

$$1 \times 10$$^{-8}$$\ \mathrm{M}$$

Question 1

Which property of water allows the insect in the image to walk on the surface of the water without sinking?

Accepted Answer

Cohesion due to hydrogen bonding

Question 2

What type of bond is primarily responsible for the high surface tension of water?

Accepted Answer

Hydrogen bonds

Question 3

Given the equation $$\mathrm{pH} = -\log [\mathrm{H}^+]$$, what is the pH of a solution with $$[\mathrm{H}^+] = 1 	imes 10$$^{-5}$$\ \mathrm{M}$$?

Accepted Answer

$$5$$

Question 4

Which of the following best describes why water is considered a polar molecule?

Accepted Answer

It has an uneven distribution of electrons, resulting in partial positive and negative charges.

Question 5

A solution has a pH of 3. Which of the following statements is true?

Accepted Answer

The solution is acidic and has a high concentration of $$\mathrm{H}^+$$ ions.

Question 6

Which of the following is a real-life example of a buffer system in the human body?

Accepted Answer

The bicarbonate buffer system in blood

Question 7

If the concentration of $$\mathrm{OH}^- in a $$solution is $$1 	imes 10$$^{-6}$$\ \mathrm{M}$$, what is the concentration of $$\mathrm{H}^+ at$$ $$25^\circC$$, given $$[\mathrm{H}^+][\mathrm{OH}^-] = 1 	imes 10$$^{-14}$$?

Accepted Answer

$$1 	imes 10$$^{-8}$$\ \mathrm{M}$$

Question 8

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

Accepted Answer

Hydrogen bonds stabilize and keep the molecules farther apart in ice than in liquid water.

Question 9

A patient’s blood pH drops from 7.4 to 7.1. What is the effect on the hydrogen ion concentration?

Accepted Answer

It increases by about a factor of three

Question 10

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

Accepted Answer

Acids increase $$[\mathrm{H}^+]$$ and decrease $$[\mathrm{OH}^-] in $$solution.

Question 11

Which of the following best describes the role of buffers in biological systems?

Accepted Answer

They minimize changes in pH by accepting or donating $$\mathrm{H}^+$$ ions.

Question 12

Which of the following molecules is nonpolar?

Accepted Answer

$$\mathrm{O}_2$$

Question 13

Which of the following is NOT a property of water that results from hydrogen bonding?

Accepted Answer

Water's ability to dissolve nonpolar substances

Question 14

A solution has a pH of 9. Which of the following best describes this solution?

Accepted Answer

It is basic and has a lower $$[\mathrm{H}^+]$$ than pure water.

Question 15

Which of the following best explains why water is an excellent solvent for ionic and polar substances?

Accepted Answer

Water's polarity allows it to surround and separate ions and polar molecules.

Question 16

Which of the following is true about the relationship between $$[\mathrm{H}^+]$$ and $$[\mathrm{OH}^-] in $$pure water at 25°C?

Accepted Answer

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

Question 17

Which of the following would most likely occur if the pH of the ocean dropped significantly due to increased atmospheric $$\mathrm{CO}_2$$?

Accepted Answer

A decrease in carbonate ion ($$\mathrm{CO}_3$$^{2-}$$) availability, affecting organisms that build shells

Question 18

Which of the following statements about adhesion and cohesion is correct?

Accepted Answer

Cohesion is the attraction between water molecules; adhesion is the attraction between water and other substances.

Question 19

Which of the following best describes what happens when an acid is added to a buffered solution?

Accepted Answer

The buffer will accept excess $$\mathrm{H}^+$$ ions, minimizing the change in pH.

Question 20

Which of the following is a correct statement about the pH scale?

Accepted Answer

Each unit change in pH represents a tenfold change in $$[\mathrm{H}^+]$$ concentration.

Chapter 3 part 2

Study Guide - Practice Questions

Study Guide - Flashcards