$$M = \frac{2}{1} = 2\ \text{M}$$

$$pH = -\log(1 \times 10$$^{-4}$$) = 4$$

$$[H^+][OH^-] = 1 \times 10$$^{-14}$$

Question 1

Which property of water allows ice to float on liquid water, and why is this important for aquatic life?

Accepted Answer

Water's expansion upon freezing; ice is less dense than liquid water, insulating aquatic life below.

Question 2

What type of bond forms between the hydrogen atom of one water molecule and the oxygen atom of another water molecule?

Accepted Answer

Hydrogen bond

Question 3

Why does water have a high specific heat compared to other substances?

Accepted Answer

Because hydrogen bonds between water molecules absorb and release heat slowly.

Question 4

A solution has a pH of 7. If the concentration of $$[H^+]$$ increases by a factor of 100, what is the new pH?

Accepted Answer

5

Question 5

Which of the following best explains why water is a versatile solvent?

Accepted Answer

Water molecules are polar, allowing them to surround and dissolve ionic and polar substances.

Question 6

Which property of water is most directly responsible for the upward movement of water in plants against gravity?

Accepted Answer

Cohesion due to hydrogen bonding

Question 7

What is the molarity ($$M) of a $$solution containing 2 moles of solute in 1 liter of water?

Accepted Answer

$$M = \frac{2}{1} = 2\ 	ext{M}$$

Question 8

Which of the following substances is hydrophobic?

Accepted Answer

Olive oil

Question 9

If a solution has $$[H^+] = 1 	imes 10$$^{-4}$$, what is its pH?

Accepted Answer

$$pH = -\log(1 	imes 10$$^{-4}$$) = 4$$

Question 10

Which of the following best describes the polarity of a water molecule?

Accepted Answer

The oxygen atom has a partial negative charge and the hydrogen atoms have partial positive charges.

Question 11

A strong acid added to water will have which effect on $$[H^+]$$ and pH?

Accepted Answer

$$[H^+]$$ increases and pH decreases

Question 12

Which of the following is an example of adhesion in biological systems?

Accepted Answer

Water molecules binding to plant cell walls during transport

Question 13

What is the product of $$[H^+]$$ and $$[OH^-] in $$any aqueous solution at 25°C?

Accepted Answer

$$[H^+][OH^-] = 1 	imes 10$$^{-14}$$

Question 14

Which property of water helps maintain stable temperatures in lakes and oceans?

Accepted Answer

High specific heat

Question 15

A solution has a pH of 8. If the $$[H^+]$$ increases by a factor of 1,000, what is the new pH?

Accepted Answer

5

Question 16

Which of the following is NOT an emergent property of water that contributes to Earth's suitability for life?

Accepted Answer

Low boiling point

Question 17

Which statement best explains why water can dissolve ionic compounds like NaCl?

Accepted Answer

Water molecules surround ions due to their polarity, separating and dissolving them.

Question 18

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

Accepted Answer

Strengthening hydrogen bonds at the surface

Question 19

Which of the following best describes a hydrophilic substance?

Accepted Answer

A substance that has an affinity for water due to its ionic or polar nature

Question 20

Which of the following is true about the density of water as it cools from 4°C to 0°C?

Accepted Answer

Water reaches its greatest density at 4°C, then becomes less dense as it freezes.

Water and Life: Properties and Importance of Water in Biology

Guida di studio - Domande di pratica