$$M = \frac{\text{moles of solute}}{\text{volume of solution (L)}}$$

Question 1

Which of the following best describes a hydrophilic substance?

Accepted Answer

A substance that has an affinity for water and readily dissolves in it.

Question 2

What is the primary reason why charged ions are disruptive to living organisms?

Accepted Answer

They tend to disrupt the structure of proteins by interfering with weak bonds.

Question 3

Which equation correctly represents the calculation of molarity ($$M) in a $$solution?

Accepted Answer

$$M = \frac{	ext{moles of solute}}{	ext{volume of solution (L)}}$$

Question 4

A solution has a pH of 4. How many times more acidic is it compared to a solution with a pH of 7?

Accepted Answer

1000 times more acidic

Question 5

Which of the following statements about acids in aqueous solutions is correct?

Accepted Answer

Acids increase the concentration of hydrogen ions in solution.

Question 6

What is the role of buffers in maintaining pH in living organisms?

Accepted Answer

Buffers maintain constant pH by picking up or releasing hydrogen ions as needed.

Question 7

Which property of water is most critical for evaporative cooling in living organisms?

Accepted Answer

Ability to form hydrogen bonds

Question 8

If a solution contains a high concentration of hydroxide ions ($$OH^-$$), what can be inferred about its pH?

Accepted Answer

The solution is basic and has a high pH.

Question 9

Which of the following best explains why carbon is so important for living organisms?

Accepted Answer

Carbon can form large, complex, and variable molecules due to its bonding properties.

Question 10

What happens when hydrochloric acid ($$HCl) is $$added to water?

Accepted Answer

$$HCl$$ dissociates into hydrogen ions ($$H^+) $$and chloride ions ($$Cl^-$$), increasing the acidity.

Question 11

Which of the following is a real-world example of a hydrophobic substance?

Accepted Answer

Oil not mixing with water

Question 12

Why are hydrogen bonds critical for the properties of water?

Accepted Answer

They give water a high boiling point and allow for cohesion and surface tension.

Question 13

A scientist wants to track the number of moles of solute in a liter of solution. Which measurement should they use?

Accepted Answer

Molarity

Question 14

Which of the following best describes the relationship between pH and hydrogen ion concentration?

Accepted Answer

As pH decreases, hydrogen ion concentration increases.

Question 15

If a living organism's blood pH drops significantly below 7, what is the most likely consequence?

Accepted Answer

The organism will experience acidosis, which can disrupt normal cellular functions.

Question 16

Which process converts carbon dioxide into organic molecules in plants?

Accepted Answer

Photosynthesis

Question 17

A student adds a strong base to a solution. What will happen to the pH and the concentration of hydrogen ions?

Accepted Answer

pH will increase and hydrogen ion concentration will decrease.

Question 18

Which of the following is a function of surface tension in water relevant to living organisms?

Accepted Answer

It enables small insects to walk on water surfaces.

Question 19

Which of the following molecules is most likely to be found in high concentration in a basic solution?

Accepted Answer

Hydroxide ions ($$OH^-)$$

Question 20

Why do living organisms need to maintain a near-neutral pH in their cells?

Accepted Answer

To ensure proper function of enzymes and cellular processes.

Water, Acids, Bases, and Carbon in Biology: Chapter 5 Study Notes

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