$$1 \times 10$$^{-4}$$ \text{ M}$$

Question 1

Which of the following statements best describes an element?

Accepted Answer

An element is a substance that cannot be broken down to other substances by chemical reactions.

Question 2

Which equation correctly represents the photosynthesis reaction?

Accepted Answer

$$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6$ + 6O_2$$

Question 3

Which property of water is primarily responsible for the formation of potholes in Chicago streets during winter?

Accepted Answer

Water expands as it freezes.

Question 4

What is the atomic mass of an atom with 6 protons and 8 neutrons?

Accepted Answer

$$14$$

Question 5

Which type of chemical bond involves the sharing of electrons between atoms?

Accepted Answer

Covalent bond

Question 6

Why does ice float on liquid water?

Accepted Answer

Hydrogen bonds in ice cause water molecules to be spaced farther apart, making ice less dense.

Question 7

Which of the following best explains why water has a high specific heat?

Accepted Answer

Multiple hydrogen bonds between water molecules require more energy to increase their movement.

Question 8

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

Accepted Answer

$$1 	imes 10$$^{-4}$$ 	ext{ M}$$

Question 9

Which of the following is a real-world application of radioactive isotopes in biology?

Accepted Answer

Radioactive isotopes are used to trace metabolic activity in PET scans.

Question 10

Which of the following elements makes up the largest percentage of the human body by mass?

Accepted Answer

Oxygen

Question 11

Which of the following best describes a buffer in biological systems?

Accepted Answer

A buffer is a substance that maintains a constant pH by picking up or releasing $$H^+$$ ions.

Question 12

Which of the following is true about isotopes of the same element?

Accepted Answer

They have the same number of electrons and react the same chemically.

Question 13

Which of the following is a consequence of water's high heat of vaporization for living organisms?

Accepted Answer

It enables evaporative cooling, helping organisms regulate temperature.

Question 14

Which of the following best explains why water is an excellent solvent for polar molecules?

Accepted Answer

Water molecules form hydrogen bonds with polar molecules, allowing them to dissolve.

Question 15

If the concentration of $$[H^+] in a $$solution is $$1 	imes 10$$^{-9}$$ 	ext{ M}$$, what is the pH of the solution?

Accepted Answer

$$9$$

Question 16

Which of the following is a result of water's cohesion?

Accepted Answer

Water molecules stick to each other, allowing surface tension.

Question 17

Which of the following best describes a chemical reaction at equilibrium?

Accepted Answer

The forward and reverse reactions occur at the same rate.

Question 18

Which of the following is true about acids in aqueous solutions?

Accepted Answer

Acids donate $$H^+$$ ions.

Question 19

A mole of sucrose ($$C_{12}H$$_{22}$$O_{11}$) weighs 342 g. How many molecules are in one mole?

Accepted Answer

$$6.02 	imes 10$$^{23}$$

Question 20

Which of the following is a direct consequence of increased atmospheric $$CO_2$$ absorption by oceans?

Accepted Answer

Ocean pH decreases, making the water more acidic.

Chemistry Fundamentals for Biology Students

Study Guide - Practice Questions