Question 1

Which of the following best describes a heterogeneous mixture?

Accepted Answer

A mixture in which the components are not uniformly distributed, such as sand in water.

Question 2

Which of the following is an example of a chemical change?

Accepted Answer

Burning of wood in a fireplace.

Question 3

A student measures the mass of a sample as $$12.34\ \mathrm{g}$$ and its volume as $$4.56\ \mathrm{cm}^3. $$What is the density of the sample, and how many significant figures should the answer have?

Accepted Answer

$$2.71\ \mathrm{g/cm}^3$$ with 3 significant figures

Question 4

Which law states that a chemical compound always contains exactly the same proportion of elements by mass?

Accepted Answer

Law of Definite Proportions

Question 5

An atom has 17 protons, 18 neutrons, and 17 electrons. What is its mass number and which element is it?

Accepted Answer

Mass number = 35, element = Chlorine

Question 6

Which of the following ions is polyatomic and carries a negative charge?

Accepted Answer

Sulfate ion, $$\mathrm{SO}_4$$^{2-}$$

Question 7

Which of the following best describes the difference between an empirical formula and a molecular formula?

Accepted Answer

The empirical formula shows the simplest whole-number ratio of atoms, while the molecular formula shows the actual number of atoms of each element in a molecule.

Question 8

A compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is the empirical formula of the compound?

Accepted Answer

$$\mathrm{CH}_2\mathrm{O}$$

Question 9

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

Accepted Answer

It has an uneven distribution of electron density due to its bent shape and difference in electronegativity between hydrogen and oxygen.

Question 10

A sample of calcium nitrate, $$\mathrm{Ca(NO}_3)_2$$, has a mass of $$164\ \mathrm{g}. $$How many moles of calcium nitrate are present in the sample? (Molar mass of $$\mathrm{Ca(NO}_3)_2 = 164\ \mathrm{g/mol})$$

Accepted Answer

$$1$$ mole

Question 11

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 12

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

Accepted Answer

Ionic bonding involves the transfer of electrons from one atom to another, while covalent bonding involves the sharing of electrons between atoms.

Question 13

A student needs to prepare $$250\ \mathrm{mL} of a$$ $$0.100\ \mathrm{M}$$ NaCl solution. How many grams of NaCl (molar mass $$= 58.44\ \mathrm{g/mol}) $$are required?

Accepted Answer

$$1.46\ \mathrm{g}$$

Question 14

Which of the following is the correct name for $$\mathrm{Fe}_2\mathrm{O}_3$$?

Accepted Answer

Iron(III) oxide

Question 15

Which of the following is the correct formula for ammonium sulfate?

Accepted Answer

$$\mathrm{(NH}_4)_2\mathrm{SO}_4$$

Question 16

A compound has an empirical formula of $$\mathrm{CH}_2\mathrm{O}$$ and a molar mass of $$180\ \mathrm{g/mol}. $$What is its molecular formula?

Accepted Answer

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6$$

Question 17

Which of the following statements about the periodic table is correct?

Accepted Answer

Elements in the same group have the same number of valence electrons.

Question 18

Which of the following is the correct order of metric prefixes from largest to smallest?

Accepted Answer

kilo, centi, milli, micro, nano

Question 19

A sample contains $$3.01 	imes 10$$^{23}$$ molecules of glucose ($$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6$$). How many moles of glucose are present?

Accepted Answer

$$0.500$$ moles

General Chemistry I: Fundamental Concepts and Skills

Study Guide - Practice Questions

Study Guide - Flashcards