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

Question 1

Which property of water allows it to move upward through the vessels of a plant against gravity?

Accepted Answer

Cohesion due to hydrogen bonding

Question 2

Why does ice float on liquid water?

Accepted Answer

Hydrogen bonds in ice are more ordered, making ice less dense than water

Question 3

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

Accepted Answer

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

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

Which of the following is an example of adhesion in plants?

Accepted Answer

Water molecules forming hydrogen bonds with cellulose in cell walls

Question 6

A scientist adds hydrochloric acid ($$HCl) to $$pure water. What happens to the pH and why?

Accepted Answer

The pH decreases because $$HCl$$ donates $$H^+$$ ions

Question 7

Which of the following best describes a hydrophobic substance?

Accepted Answer

A substance that does not have an affinity for water and contains nonpolar bonds

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 emergent property of water is most directly responsible for the cooling effect of sweating?

Accepted Answer

Ability to moderate temperature due to high heat of vaporization

Question 10

Which of the following equations correctly represents the dissociation of water?

Accepted Answer

$$H_2O \rightarrow H^+ + OH^-$$

Question 11

A lake has a pH of 6. After acid rain, the pH drops to 4. What is the new $$[H^+]$$ concentration compared to the original?

Accepted Answer

It is 100 times higher

Question 12

Which of the following is NOT one of the four emergent properties of water that contribute to Earth's suitability for life?

Accepted Answer

High viscosity

Question 13

What is the main reason oil does not dissolve in water?

Accepted Answer

Oil molecules contain nonpolar bonds and are hydrophobic

Question 14

Which process is responsible for the formation of carbonic acid in oceans due to human activities?

Accepted Answer

Ocean acidification from dissolved $$CO_2$$

Question 15

Which of the following best describes the role of hydrogen bonds in water’s surface tension?

Accepted Answer

Hydrogen bonds increase surface tension by holding water molecules together at the surface

Question 16

A solution contains $$1 	imes 10$$^{-7}$$ M H$$^+$$. What is its pH?

Accepted Answer

$$pH = 7$$

Question 17

Which of the following is a base according to the study materials?

Accepted Answer

A compound that accepts $$H^+$$ ions

Question 18

Which property of water is most important for its role as the 'solvent of life'?

Accepted Answer

Its polarity and ability to form hydrogen bonds

Question 19

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

Accepted Answer

Evaporation of water removes molecules with the highest kinetic energy

Question 20

Which of the following is true about the pH scale?

Accepted Answer

A solution with pH 2 has more $$H^+$$ ions than a solution with pH 6

Water and Life: Properties and Importance in Biology

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