pH = $$-\log(3.0 \times 10$$^{-5}$$) = 4.5$$

Question 1

Which of the following best describes the valence shell of an atom?

Accepted Answer

The outermost shell with electrons.

Question 2

How many unpaired electrons are present in a neutral carbon atom?

Accepted Answer

4

Question 3

A covalent chemical bond is one in which:

Accepted Answer

Outer-shell electrons of two atoms are shared so as to satisfactorily fill their respective orbitals.

Question 4

Which type of bond is responsible for the interaction between water molecules that gives water its unique properties?

Accepted Answer

Hydrogen bond

Question 5

Why are hydrocarbons generally insoluble in water?

Accepted Answer

The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages.

Question 6

Which of the following molecules contains a double covalent bond?

Accepted Answer

Carbon dioxide ($$CO_2)$$

Question 7

What is the term for the interaction between the partial positive hydrogen of one water molecule and the partial negative oxygen of another?

Accepted Answer

Hydrogen bond

Question 8

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

Accepted Answer

Oxygen is more electronegative than hydrogen, causing unequal sharing of electrons.

Question 9

Which of the following substances is the most acidic?

Accepted Answer

Lemon juice

Question 10

Which of the following substances has the highest pH?

Accepted Answer

Bleach

Question 11

Which of the following substances has the highest concentration of protons ($$[H^+]$$)?

Accepted Answer

Lemon juice

Question 12

What is the formula for calculating pH from proton concentration?

Accepted Answer

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

Question 13

You have a solution with a proton concentration of $$3.0 	imes 10$$^{-5}$$ M. What is the pH of this solution?

Accepted Answer

pH = $$-\log(3.0 	imes 10$$^{-5}$$) = 4.5$$

Question 14

If a solution has a pH of 4.7, what is its proton concentration ($$[H^+]$$)?

Accepted Answer

$$[H^+] = 10$$^{-4.7}$$ M

Question 15

Hydrochloric acid ($$HCl) is a $$strong acid that dissociates completely in water. What is the pH of a $$10^{-2} M$$ $$HCl$$ solution?

Accepted Answer

pH = 2

Question 16

Acid rain has a proton concentration 10,000 times greater than pure water. If pure water has a pH of 7, what is the approximate pH of acid rain?

Accepted Answer

pH = 3

Question 17

Farmer Jen adds lime to her soil to increase the pH from 4 to 6. What happens to the proton concentration in the soil?

Accepted Answer

It decreases by a factor of 100.

Question 18

Which of the following best describes the difference between polar and nonpolar covalent bonds?

Accepted Answer

Polar covalent bonds involve unequal sharing of electrons due to differences in electronegativity.

Question 19

Which of the following is a real-world consequence of water's ability to form hydrogen bonds?

Accepted Answer

Water has a high specific heat, helping regulate climate and body temperature.

Chemical Basis of Life: Atoms, Bonds, and Water Chemistry

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