Question 1

Which of the following statements about a neutral atom is correct?

Accepted Answer

The number of protons equals the number of electrons.

Question 2

How many valence electrons does an atom of phosphorus (P, group 5A) have?

Accepted Answer

5

Question 3

Which of the following best describes the bonding in sodium chloride (NaCl)?

Accepted Answer

Ionic bonds with transferred electrons

Question 4

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

Accepted Answer

CO2

Question 5

What is the molecular geometry of ammonia ($$NH_3$$)?

Accepted Answer

Pyramidal

Question 6

Which of the following is required for hydrogen bonding between two molecules?

Accepted Answer

Hydrogen attached to O, N, or F and a lone pair on O, N, or F

Question 7

Which intermolecular force is present in all molecules, regardless of polarity?

Accepted Answer

London dispersion

Question 8

A solution of sodium chloride (NaCl) in water conducts electricity because:

Accepted Answer

NaCl dissociates into ions in water

Question 9

Which of the following best explains why water ($$H_2O) $$has a higher boiling point than methane ($$CH_4$$)?

Accepted Answer

Water forms hydrogen bonds.

Question 10

Which of the following mixtures will result in a solution due to 'like dissolves like'?

Accepted Answer

Ethanol (polar) and water (polar)

Question 11

Which of the following is true at chemical equilibrium?

Accepted Answer

The forward and reverse reaction rates are equal.

Question 12

Given the reaction $$aA + bB \rightleftharpoons mM + nN$$, the equilibrium constant $$K is$$:

Accepted Answer

$$K = \frac{[M]^m [N]^n}{[A]^a [B]^b}$$

Question 13

If a reactant is removed from a system at equilibrium, what will happen according to Le Chatelier’s Principle?

Accepted Answer

The reaction will shift to produce more reactants.

Question 14

Which of the following is a correct definition of a Brønsted-Lowry acid?

Accepted Answer

A substance that donates an $$H^+$$

Question 15

Which acid is stronger: $$K_a = 1 	imes 10$$^{-2}$$ or K_a = 1$$ 	imes $$10^{-3}$$?

Accepted Answer

$$K_a = 1 	imes 10$$^{-2}$$

Question 16

A buffer solution is prepared by mixing acetic acid and sodium acetate. What happens to the pH if a small amount of strong acid is added?

Accepted Answer

The pH decreases slightly, but much less than in pure water.

Question 17

Which of the following equations is the Henderson-Hasselbalch equation for calculating the pH of a buffer?

Accepted Answer

$$	ext{pH} = 	ext{p}K_a + \log \left( \frac{[	ext{base}]}{[	ext{acid}]} ight)$$

Question 18

Which of the following intermolecular forces can the amino acid aspartic acid participate in?

Accepted Answer

All of the above

Question 19

Which of the following best explains why buffers are important in biological systems?

Accepted Answer

They prevent large changes in pH.

CHEM 1120 Review: Atoms, Bonding, Intermolecular Forces, Equilibrium, and Acids/Bases

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