Question 1

Which property of water allows water striders to walk on its surface?

Accepted Answer

Surface tension due to cohesion

Question 2

Why is water considered a 'heat bank' in biological systems?

Accepted Answer

It has a high specific heat, resisting temperature changes

Question 3

What is the chemical equation for the dissociation of water?

Accepted Answer

$$\mathrm{H_2O \rightarrow H^+ + OH^-}$$

Question 4

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

Accepted Answer

Hydrogen bonding causes ice to be less dense than liquid water

Question 5

A solution with a pH of 4 has how many times more hydrogen ions than a solution with a pH of 6?

Accepted Answer

100 times

Question 6

Which statement about buffers is correct?

Accepted Answer

Buffers help maintain a constant pH by absorbing excess H$$^+ or OH$^-$$ ions

Question 7

What is the formula for calculating pH?

Accepted Answer

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

Question 8

Which of the following is a hydrophilic substance?

Accepted Answer

Salt (NaCl)

Question 9

If you add a strong acid to water, what happens to the concentration of H$$^+$$ ions?

Accepted Answer

It increases

Question 10

Which property of water is most important for the survival of aquatic life in winter?

Accepted Answer

Ice floating due to lower density

Question 11

A buffer is added to a solution with a pH of 7.4. If a small amount of acid is added, what will happen to the pH?

Accepted Answer

It will remain close to 7.4

Question 12

Which of the following best describes the polarity of water?

Accepted Answer

Electrons spend more time around O, giving it a partial negative charge

Question 13

Which of the following is NOT a property of water that is crucial for life?

Accepted Answer

Ice being denser than liquid water

Question 14

If the temperature of 1g of water is raised by 1°C, how much energy is required?

Accepted Answer

1 calorie

Question 15

Which of the following would increase the surface tension of water?

Accepted Answer

Increasing hydrogen bonding between water molecules

Question 16

A lake is covered with ice in winter. What property of water allows fish to survive underneath?

Accepted Answer

Ice is less dense than liquid water, so it floats

Question 17

Which of the following is true about acids?

Accepted Answer

They release hydrogen ions (H$$^+) in $$water

Question 18

What happens to the pH of a solution if the concentration of H$$^+$$ ions increases from $$10^{-7} M to$$ $$10^{-5} M$$?

Accepted Answer

pH decreases from 7 to 5

Question 19

Which of the following best describes a hydrophobic molecule?

Accepted Answer

It repels water and does not dissolve

Question 20

Which of the following is an example of a buffer in the human body?

Accepted Answer

Bicarbonate in blood

Water and Life: Properties, Acids/Bases, and Buffers (Chapter 3 Study Notes)

Study Guide - Practice Questions