Question 1

Which of the following best describes a buffer solution, as shown in the first image?

Accepted Answer

A solution containing a weak acid and its conjugate base that resists changes in pH.

Question 2

What is the correct chemical equation for the dissociation of acetic acid (HC2H3O2) in water?

Accepted Answer

$$ \mathrm{HC_2H_3O_2} \rightarrow \mathrm{C_2H_3O_2^-} + \mathrm{H^+} $$

Question 3

Which of the following is true about the molecular geometry of water, as shown in the second image?

Accepted Answer

Water has a bent geometry with a bond angle of approximately 104.5°.

Question 4

Which intermolecular force is primarily responsible for the high boiling point of water, as depicted in the sixth image?

Accepted Answer

Hydrogen bonding

Question 5

Based on the periodic trend diagram (fifth image), which element would have the highest ionization energy?

Accepted Answer

Fluorine (F)

Question 6

What is the effect of a catalyst on the activation energy of a reaction, as shown in the sixth image?

Accepted Answer

A catalyst decreases the activation energy, making the reaction faster.

Question 7

Which of the following best describes the polarity of a water molecule, as shown in the seventh image?

Accepted Answer

Water is polar due to the bent shape and difference in electronegativity between H and O.

Question 8

Which of the following statements about atomic structure is supported by the eighth image?

Accepted Answer

Protons and neutrons are found in the nucleus, which is much smaller than the overall atom.

Question 9

Which of the following best explains why sodium chloride (NaCl) dissolves in water, as shown in the image with water molecules surrounding ions?

Accepted Answer

Ion-dipole interactions between water molecules and Na+ and Cl- ions allow NaCl to dissolve.

Question 10

Which of the following is the correct Lewis structure for a sulfur atom, as shown in the image with the letter 'S' and six dots?

Accepted Answer

Sulfur with six dots around it

Question 11

Which of the following best describes the relationship between atomic number and the identity of an element?

Accepted Answer

The atomic number is the number of protons in the nucleus and determines the element.

Question 12

Which of the following is true about the effect of adding a strong acid to a buffer solution, as shown in the first image?

Accepted Answer

The buffer neutralizes some of the added acid, so the pH drops only slightly.

Question 13

Which of the following best describes the trend in atomic radius across a period in the periodic table, as shown in the periodic trend diagram?

Accepted Answer

Atomic radius decreases from left to right across a period.

Question 14

Which of the following is the correct formula for calculating pH?

Accepted Answer

$$ \mathrm{pH} = -\log [\mathrm{H^+}] $$

Question 15

Which of the following best describes the difference between a molecule and a polyatomic ion, as illustrated by phosphoric acid and phosphate?

Accepted Answer

A polyatomic ion has a charge, while a molecule does not.

Question 16

Which of the following is true about the effect of intermolecular forces on boiling points?

Accepted Answer

Stronger intermolecular forces result in higher boiling points.

CHEM 1120 Review: Atoms, Periodic Table, Ionic and Covalent Compounds, Intermolecular Forces, Solutions, Equilibrium, Acids & Bases, and Buffers

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