Q: A solution has a hydrogen ion concentration of $$[H^+] = 1 \times 10$$^{-5}$$ M. What is the pH of this solution?

$$pH = -\log_{10}(1 \times 10$$^{-5}$$) = 5$$

Question 1

Which of the following best describes a trace element in living organisms?

Accepted Answer

An element required in minute quantities but essential for life

Question 2

A neutral atom of carbon has an atomic number of 6 and a mass number of 14. How many neutrons does it have?

Accepted Answer

$$14 - 6 = 8$$ neutrons

Question 3

Which of the following statements about isotopes is correct?

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons

Question 4

Which of the following best explains why water is a polar molecule?

Accepted Answer

Oxygen is more electronegative than hydrogen, creating a partial negative charge near the oxygen atom and a partial positive charge near the hydrogen atoms

Question 5

Which property of water allows it to moderate Earth's climate by absorbing and releasing heat with only slight temperature changes?

Accepted Answer

High specific heat

Question 6

A solution has a hydrogen ion concentration of $$[H^+] = 1 	imes 10$$^{-5}$$ M. What is the pH of this solution?

Accepted Answer

$$pH = -\log_{10}(1 	imes 10$$^{-5}$$) = 5$$

Question 7

Which of the following best describes a covalent bond?

Accepted Answer

A bond formed by the sharing of electrons between two atoms

Question 8

Which of the following is a real-life example of a buffer system in biological organisms?

Accepted Answer

The bicarbonate buffer system in human blood

Question 9

If a solution changes from pH 6 to pH 4, how does the hydrogen ion concentration change?

Accepted Answer

It increases by 100 times

Question 10

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

Accepted Answer

Hydrogen bonds stabilize and keep water molecules farther apart in ice, making it less dense than liquid water

Question 11

Which of the following is NOT a property of water that results from hydrogen bonding?

Accepted Answer

Water's ability to dissolve nonpolar substances

Question 12

A patient is diagnosed with acidosis, meaning their blood pH is below normal. Which of the following would help restore normal pH?

Accepted Answer

Increasing the concentration of bicarbonate ions ($$HCO_3$$^-$$) in the blood

Question 13

Which of the following best describes an ionic bond?

Accepted Answer

A bond formed by the transfer of electrons from one atom to another, resulting in oppositely charged ions

Question 14

Which of the following best explains why salt (NaCl) dissolves easily in water?

Accepted Answer

The partial positive charge of water's hydrogen atoms attracts the chloride ions, and the partial negative charge of water's oxygen atoms attracts the sodium ions

Question 15

Which of the following is a correct statement about the relationship between atomic number and mass number?

Accepted Answer

Atomic number is the number of protons, while mass number is the sum of protons and neutrons

Question 16

Which of the following best describes a hydrophobic substance?

Accepted Answer

A substance that does not interact with water because it is nonpolar

Question 17

Which of the following is an example of a real-life application of the concept of half-life?

Accepted Answer

Using carbon-14 dating to estimate the age of ancient fossils

Question 18

Which of the following best explains why water is an effective solvent for ionic compounds?

Accepted Answer

Water's polarity allows it to surround and separate ions

Question 19

A solution has a pH of 8. Which of the following statements is true?

Accepted Answer

The solution is basic, and $$[OH^-] \u003e [H^+]$$

Question 20

Which of the following best describes the difference between a molecule and a compound?

Accepted Answer

A molecule consists of two or more atoms held together by covalent bonds, while a compound consists of two or more different elements combined in a fixed ratio

Fundamental Chemistry Concepts in General Biology

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