Q: What is the molarity of hydroxide ions $$[OH^-] in a $$solution with pH = 10?

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

Question 1

Which property of water allows it to move upward from the roots to the leaves in plants, as shown in the diagram of water transport in trees?

Accepted Answer

Cohesion and adhesion due to hydrogen bonding

Question 2

What type of bond is responsible for the partial negative charge on the oxygen atom and partial positive charges on the hydrogen atoms in a water molecule?

Accepted Answer

Polar covalent bond

Question 3

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

Accepted Answer

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

Question 4

Which of the following best explains why coastal cities tend to have milder climates than inland cities at the same latitude, as shown in the temperature map?

Accepted Answer

Water's high specific heat moderates temperature changes

Question 5

What is the main reason oil does not dissolve in water, as illustrated by the interaction of water with hydrophobic molecules?

Accepted Answer

Oil molecules are nonpolar and cannot form hydrogen bonds with water

Question 6

Which equation correctly represents the dissociation of water molecules?

Accepted Answer

$$2\ \mathrm{H_2O} \rightleftharpoons \mathrm{H_3O^+} + \mathrm{OH^-}$$

Question 7

A buffer system in human blood involves carbonic acid ($$\mathrm{H_2CO_3}) $$and bicarbonate ion ($$\mathrm{$$HCO_3$$^-}). $$What is the main function of this buffer system?

Accepted Answer

To maintain a stable pH by accepting or donating $$\mathrm{H^+}$$ ions

Question 8

If the pH of a solution changes from 6 to 4, how does the hydrogen ion concentration change?

Accepted Answer

It increases by 100 times

Question 9

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

Accepted Answer

Hydrogen bonds stabilize and keep water molecules farther apart in ice

Question 10

A scientist adds a strong acid to a beaker of pure water. What will happen to the pH and the $$[OH^-]$$ concentration?

Accepted Answer

pH will decrease and $$[OH^-]$$ will decrease

Question 11

Which of the following is a real-life example of water’s high surface tension?

Accepted Answer

A water strider insect walking on the surface of a pond

Question 12

What is the molarity of hydroxide ions $$[OH^-] in a $$solution with pH = 10?

Accepted Answer

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

Question 13

Which of the following best describes a hydrophilic substance?

Accepted Answer

A substance that has an affinity for water and dissolves easily

Question 14

Which of the following equations correctly expresses the relationship between hydrogen ion and hydroxide ion concentrations in water at 25°C?

Accepted Answer

$$[H^+][OH^-] = 10$$^{-14}$$

Question 15

A protein in your body requires a constant pH to function properly. What should be present in the solution to maintain this pH?

Accepted Answer

A buffer

Question 16

Which of the following is an example of water acting as a solvent in a biological system?

Accepted Answer

Dissolving sodium chloride (NaCl) in water

Question 17

If a solution has a pH of 8, how does its hydrogen ion concentration compare to a solution with a pH of 5?

Accepted Answer

It has 1,000 times fewer hydrogen ions

Question 18

Which property of water is most responsible for the formation of hydration shells around ions in solution?

Accepted Answer

Polarity of water molecules

Question 19

Which of the following best describes the role of hydrogen bonds in water’s high specific heat?

Accepted Answer

Hydrogen bonds absorb heat when they break and release heat when they form

Question 20

Which of the following would most likely occur if the surface tension of water was greatly reduced?

Accepted Answer

Water striders would sink

Water and Life: Properties, Structure, and Biological Importance

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