$$[H^+] = 1 \times 10$$^{-5}$$ mol/L

Question 1

Which subatomic particle is responsible for the chemical properties of an atom, and why?

Accepted Answer

Electrons, because their arrangement in shells determines reactivity.

Question 2

An isotope of carbon has 6 protons and 8 neutrons. What is its atomic mass, and how does it differ from the most common isotope?

Accepted Answer

Atomic mass is 14; it has more neutrons than the common isotope.

Question 3

Which equation correctly represents the calculation of pH from hydrogen ion concentration $$[H^+]$$?

Accepted Answer

$$pH = -\log_{10}([H^+])$$

Question 4

A solution has a pH of 5. What is its $$[H^+]$$ concentration in mol/L?

Accepted Answer

$$[H^+] = 1 	imes 10$$^{-5}$$ mol/L

Question 5

Which of the following best describes the difference between ionic and covalent bonds?

Accepted Answer

Ionic bonds involve the transfer of electrons; covalent bonds involve the sharing of electrons.

Question 6

Why is water considered a polar molecule, and how does this property affect its biological function?

Accepted Answer

Water is polar due to unequal sharing of electrons, enabling it to dissolve many ionic and polar substances.

Question 7

Which functional group is commonly found in amino acids and is responsible for their acidic properties?

Accepted Answer

Carboxyl group ($$-COOH)$$

Question 8

A molecule contains both hydrophilic and hydrophobic regions. What term best describes this molecule, and what is its biological significance?

Accepted Answer

Amphipathic; it can form cell membranes by arranging in bilayers.

Question 9

If the pH of a solution changes from 7 to 5, how does the hydrogen ion concentration change?

Accepted Answer

It increases by 100 times.

Question 10

Which of the following molecules is most likely to be nonpolar?

Accepted Answer

Oxygen gas ($$O_2)$$

Question 11

How do hydrogen bonds contribute to the properties of water that are essential for life?

Accepted Answer

They allow water to have a high specific heat and surface tension.

Question 12

Which of the following is a correct statement about the role of valence electrons in chemical bonding?

Accepted Answer

Valence electrons determine the type and number of bonds an atom can form.

Question 13

A solution with a pH of 2 is considered:

Accepted Answer

Acidic

Question 14

Which of the following best explains why nonpolar molecules do not dissolve well in water?

Accepted Answer

Nonpolar molecules lack charged regions to interact with water's polarity.

Question 15

Which functional group is responsible for the basic properties of amino acids?

Accepted Answer

Amino group ($$-NH_2$)

Question 16

How do the chemical properties of molecules influence their roles in cellular processes?

Accepted Answer

They determine how molecules interact, affecting structure and function.

Question 17

Which of the following statements about polarity is correct?

Accepted Answer

Polar molecules have an uneven distribution of charge, leading to partial positive and negative regions.

Question 18

A molecule with a phosphate group is likely to be involved in which biological process?

Accepted Answer

Energy transfer, such as in ATP.

Question 19

Which of the following is a real-world example of a covalent bond?

Accepted Answer

The bond between hydrogen and oxygen in a water molecule.

Question 20

If a molecule is described as hydrophobic, what does this mean in terms of its interaction with water?

Accepted Answer

It repels water and does not dissolve easily.

Chemical Foundations of Life: Atoms, Bonds, and Water in Biology

Study Guide - Practice Questions