Question 1

Which of the following best describes the scientific method as applied in chemistry?

Accepted Answer

A process involving observation, hypothesis formation, experimentation, and revision based on evidence.

Question 2

Which of the following is an example of applying dimensional analysis in chemistry?

Accepted Answer

Converting 25 grams of NaCl to moles using the molar mass.

Question 3

A student observes that a solution changes color when a chemical is added. Which step of the scientific method does this represent?

Accepted Answer

Making an observation

Question 4

Which of the following statements about acids and bases is correct?

Accepted Answer

A strong acid completely dissociates in water, while a weak acid only partially dissociates.

Question 5

Which equation correctly represents the relationship between mass, molar mass, and moles?

Accepted Answer

$$n = \frac{m}{M}$$

Question 6

A compound has the formula $$\mathrm{Na_2SO_4}. $$What is its correct name?

Accepted Answer

Sodium sulfate

Question 7

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

Accepted Answer

Water molecules form hydrogen bonds, which are stronger than the dispersion forces in methane.

Question 8

Which of the following is a correct application of the VSEPR model?

Accepted Answer

Predicting that $$\mathrm{CO_2$} is $$linear because it has two regions of electron density around the central atom.

Question 9

A reaction is at equilibrium. Which statement is true?

Accepted Answer

The concentrations of reactants and products remain constant over time.

Question 10

Which of the following best describes an oxidation-reduction (redox) reaction?

Accepted Answer

A reaction in which electrons are transferred from one species to another.

Question 11

Which of the following is a real-world example of a chemical reaction involving oxidation and reduction?

Accepted Answer

The rusting of iron in the presence of oxygen and water.

Question 12

Which of the following best explains why ionic compounds tend to have high melting points?

Accepted Answer

Strong electrostatic forces between oppositely charged ions require a large amount of energy to break.

Question 13

A solution is prepared by dissolving 10.0 g of NaCl in enough water to make 500 mL of solution. What is the molarity of the solution? ($$\mathrm{M_{NaCl} = 58.44\ g/mol})$$

Accepted Answer

$$0.342\ \mathrm{M}$$

Question 14

Which of the following statements about intermolecular forces is correct?

Accepted Answer

Hydrogen bonding occurs when hydrogen is bonded to N, O, or F.

Question 15

Which of the following best describes a chemical equilibrium?

Accepted Answer

The rates of the forward and reverse reactions are equal.

Question 16

Which of the following is a correct example of a balanced chemical equation?

Accepted Answer

$$2\mathrm{H_2$} + \mathrm{O_2$} \rightarrow 2\mathrm{H_2O}$$

Question 17

Which of the following best explains why salt (NaCl) dissolves in water but not in oil?

Accepted Answer

Water is polar and can stabilize the ions, while oil is nonpolar and cannot.

Question 18

Which of the following is a correct statement about the pH scale?

Accepted Answer

A solution with pH 3 is more acidic than a solution with pH 7.

Question 19

Which of the following is an example of using chemistry knowledge to solve a real-world problem?

Accepted Answer

Using stoichiometry to determine the amount of fertilizer needed for a crop.

Question 20

Which of the following best describes the difference between a physical and a chemical change?

Accepted Answer

A chemical change results in the formation of new substances, while a physical change does not.

CHEM-C 101 Elementary Chemistry I: Syllabus and Study Guide

Guida di studio - Domande di pratica

Study guide - Flashcard