Question 1

Which of the following best describes an ionic compound?

Accepted Answer

A compound consisting of cations and anions held together by electrostatic forces.

Question 2

Which formula represents the empirical formula for glucose?

Accepted Answer

$\mathrm{CH_2O}$

Question 3

A sample contains 0.490 mol of glucose ($\mathrm{C_6H_{12}O_6}$). How many molecules of glucose are present?

Accepted Answer

$2.95 	imes 10^{23}$

Question 4

Which of the following is a molecular element?

Accepted Answer

$\mathrm{O_2}$

Question 5

What is the percent by mass of chromium in lead(II) chromate ($\mathrm{PbCrO_4}$)? (Molar mass = $323.20\ \mathrm{g\ mol^{-1}}$, Cr = $52.00\ \mathrm{g\ mol^{-1}}$)

Accepted Answer

$16.09\%$

Question 6

Which statement correctly distinguishes between elements and compounds?

Accepted Answer

Elements consist of only one kind of atom, while compounds consist of two or more kinds of atoms chemically bonded.

Question 7

Which of the following is the correct formula mass for calcium hydroxide ($\mathrm{Ca(OH)_2}$)? (Ca = $40.08\ \mathrm{g\ mol^{-1}}$, O = $16.00\ \mathrm{g\ mol^{-1}}$, H = $1.008\ \mathrm{g\ mol^{-1}}$)

Accepted Answer

$74.096\ \mathrm{g\ mol^{-1}}$

Question 8

Which of the following samples contains the largest number of molecules?

Accepted Answer

$10\ \mathrm{g}$\ $\mathrm{C_2H_2}$

Question 9

Which of the following is NOT a property of molecular compounds?

Accepted Answer

Empirical formula represents the formula unit.

Question 10

How many carbon atoms are present in 0.400 mole of procaine ($\mathrm{C_{13}H_{20}N_2O_2}$)?

Accepted Answer

$3.13 	imes 10^{24}$

Question 11

Which of the following best describes an empirical formula?

Accepted Answer

Shows the relative numbers and types of atoms in a molecule.

Question 12

A neutral atom that loses one or more electrons forms:

Accepted Answer

A cation

Question 13

What is the percent by mass of oxygen in lead(II) chromate ($\mathrm{PbCrO_4}$)? (Molar mass = $323.20\ \mathrm{g\ mol^{-1}}$, O = $16.00\ \mathrm{g\ mol^{-1}}$)

Accepted Answer

$19.80\%$

Question 14

Which of the following is an example of a molecular formula?

Accepted Answer

$\mathrm{H_2O}$

Question 15

Which of the following is a correct statement about compounds?

Accepted Answer

Compounds have properties different from their components.

Question 16

What is the mass percent of lead in lead(II) chromate ($\mathrm{PbCrO_4}$)? (Pb = $207.20\ \mathrm{g\ mol^{-1}}$, molar mass = $323.20\ \mathrm{g\ mol^{-1}}$)

Accepted Answer

$64.11\%$

Question 17

Which of the following is NOT a mixture?

Accepted Answer

NaCl (table salt)

Question 18

Which of the following is a correct approach to determine the percent composition of a compound?

Accepted Answer

Using percent composition formula

Question 19

Which of the following is an example of an atomic element?

Accepted Answer

$\mathrm{Fe}$

Question 20

Which of the following statements about ionic compounds is correct?

Accepted Answer

Ionic compounds are held together by electrostatic forces between ions.

CH3-1: Molecules, Compounds, and Nomenclature: Chemical Formulas, Ionic Compounds, and the Mole Concept

Study Guide - Practice Questions

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