WorksheetsChapter 3: Molecules and Compounds
Total questions: 100
Worksheet time: 50mins
What is a chemical bond?
A force that holds atoms together in a compound.
A type of chemical reaction.
A process of breaking down molecules.
A method of separating mixtures.
Which of the following best defines an ionic bond?
A bond formed by the transfer of electrons from one atom to another.
A bond formed by sharing electrons equally.
A bond formed by sharing electrons unequally.
A bond formed by the attraction between molecules.
What is an ionic compound?
A compound composed of positive and negative ions held together by ionic bonds.
A compound formed by covalent bonds.
A compound that contains only hydrogen and oxygen.
A compound that cannot conduct electricity.
Compare the properties of hydrogen (H₂), oxygen (O₂), and water (H₂O). Which statement is correct?
H₂ and O₂ are gases, while H₂O is a liquid at room temperature.
H₂, O₂, and H₂O are all solids at room temperature.
H₂ and O₂ are liquids, while H₂O is a gas at room temperature.
H₂, O₂, and H₂O all have the same properties.
How do the properties of sodium (Na), chlorine (Cl₂), and sodium chloride (NaCl) compare?
Na is a reactive metal, Cl₂ is a poisonous gas, and NaCl is a safe, edible salt.
Na and Cl₂ are both edible, while NaCl is poisonous.
NaCl is a gas, while Na and Cl₂ are solids.
Na and Cl₂ are both salts, while NaCl is a metal.
Which of the following best describes a covalent bond?
A bond formed by the sharing of electrons between atoms
A bond formed by the transfer of electrons from one atom to another
A bond formed by the attraction between oppositely charged ions
A bond formed by the sharing of protons between atoms
What is a molecular (covalent) compound?
A compound formed by ionic bonds
A compound formed by metallic bonds
A compound formed by covalent bonds between nonmetals
A compound formed by hydrogen bonds
Which term refers to the number written below and to the right of a chemical symbol in a formula, indicating the number of atoms of that element?
Coefficient
Subscript
Superscript
Prefix
What is the main difference between an empirical formula and a molecular formula?
Empirical formula shows the actual number of atoms, molecular formula shows the simplest ratio
Empirical formula shows the simplest ratio, molecular formula shows the actual number of atoms
Both show the same information
Empirical formula is only used for ionic compounds
Which formula provides information about the arrangement of atoms within a molecule?
Empirical formula
Molecular formula
Structural formula
Chemical symbol
What is a ball and stick molecular model used for?
To show the mass of a molecule
To represent the three-dimensional structure and bonding of a molecule
To display the color of atoms
To measure the temperature of a reaction
What does a space-filling molecular model illustrate?
The relative sizes and spatial relationships of atoms in a molecule
The color of each atom
The boiling point of a compound
The number of electrons in each atom
Which of the following is NOT a way to represent the structure of methane, CH₄?
Empirical formula
Ball and stick model
Space-filling model
Lewis dot structure
Which of the following best defines an atomic element?
A substance made up of only one type of atom, such as helium (He)
A molecule consisting of two atoms of the same element
A compound formed from positive and negative ions
A group of atoms bonded together with a net charge
What is a molecular element?
A compound made of different elements
A molecule consisting of atoms of the same element bonded together, such as O₂
A single atom of an element
A group of ions held together by ionic bonds
Which of the following is an example of a diatomic molecule?
H₂
CO₂
NaCl
SO₄²⁻
What is a polyatomic molecule?
A molecule with only two atoms
A molecule containing more than two atoms, such as ozone (O₃)
A single atom with a charge
A compound made of ions
Which of the following best describes a molecular compound?
A compound formed from ions
A compound made up of molecules, such as H₂O
A single atom of an element
A group of atoms with a net charge
What is an ionic compound?
A compound made up of molecules
A compound formed from positive and negative ions, such as NaCl
A molecule with more than two atoms
A single atom with a charge
Which of the following is a formula unit?
The smallest repeating unit of an ionic compound, such as NaCl
A molecule with two atoms
A group of atoms with a net charge
A single atom of an element
What is a polyatomic ion?
A single atom with a positive or negative charge
A molecule with only two atoms
A group of atoms bonded together with a net charge, such as SO₄²⁻
A compound made up of molecules
Why is it incorrect to refer to ionic compounds as molecules?
Because ionic compounds are made of atoms bonded covalently
Because ionic compounds do not have discrete molecules, but rather a lattice structure
Because ionic compounds are always gases
Because ionic compounds are only found in living organisms
How do ionic compounds exist in nature?
As individual molecules
As a continuous network of ions in a crystal lattice
As isolated atoms
As liquids only
What does it mean to be "charge neutral" in the context of ionic compounds?
The compound has an overall positive charge
The compound has an overall negative charge
The total positive and negative charges in the compound balance each other out
The compound does not contain any ions
Which of the following is an example of an ionic compound commonly found in food?
Glucose
Sodium chloride (table salt)
Sucrose
Ethanol
Which of the following best summarizes the way to write an ionic compound formula?
Write the symbols of the elements in alphabetical order
Balance the total positive and negative charges so the compound is neutral
Use only the first letter of each element
Write the metal first, then the nonmetal, without considering charges
What types of elements are ionic compounds usually composed of?
Metals and nonmetals
Only metals
Only nonmetals
Metalloids and noble gases
What is ALWAYS the first step in naming an ionic compound?
Write the name of the cation first
Write the name of the anion first
Balance the charges
List the elements alphabetically
What are the two types of ionic compounds that can be formed?
Binary and ternary
Binary and polyatomic
Covalent and metallic
Organic and inorganic
Define: Binary compound
A compound composed of two different elements
A compound composed of three different elements
A compound composed of only one element
A compound composed of metals only
What are the two parts of the name of a binary compound? Give an example.
Name of the cation and name of the anion (e.g., sodium chloride)
Name of the metal and name of the nonmetal (e.g., iron oxide)
Name of the element and its oxidation state (e.g., iron(III))
Name of the molecule and its charge (e.g., ammonium ion)
Define: Common names
Names that are widely used and recognized, not based on systematic rules
Names based on the number of atoms in a molecule
Names that use Roman numerals to indicate charge
Names that are only used in scientific literature
Define: Systematic names
Names based on a set of rules established by IUPAC
Names that are only used in everyday language
Names that are based on color
Names that are based on taste
What must always be included in the name of an ionic compound that contains a metal that forms more than one cation?
The charge of the metal ion
The color of the compound
The melting point of the compound
The number of atoms in the compound
What are the three parts of the name of a binary compound with a multivalent metal?
Metal name, charge of metal, nonmetal name with -ide ending
Nonmetal name, metal name, color
Metal name, number of atoms, nonmetal name
Nonmetal name, charge of metal, melting point
What type of element will always be listed first in an ionic compound?
Metal
Nonmetal
Noble gas
Metalloid
What ending is added to the name of the nonmetal ion in a binary ionic compound?
-ide
-ate
-ite
-ous
What is unique about how compounds containing polyatomic ions are named?
The polyatomic ion name remains unchanged in the compound name
The polyatomic ion is always listed last
The polyatomic ion is always written in parentheses
The polyatomic ion is omitted from the name
What are oxyanions?
Polyatomic ions that contain oxygen
Ions that contain only hydrogen
Ions that contain only metals
Polyatomic ions that contain nitrogen
How do the suffixes -ate and -ite differentiate between oxyanions?
-ate indicates more oxygen atoms, -ite indicates fewer oxygen atoms
-ate indicates fewer oxygen atoms, -ite indicates more oxygen atoms
-ate indicates the presence of hydrogen, -ite indicates the presence of nitrogen
-ate and -ite are used interchangeably
How do the prefixes hypo- and per- differentiate between oxyanions?
Hypo- indicates the least oxygen, per- indicates the most oxygen
Hypo- indicates the most oxygen, per- indicates the least oxygen
Hypo- and per- are used for cations only
Hypo- and per- are used for naming acids only
What is the definition of a hydrate?
A compound that contains water molecules within its crystal structure.
A compound that contains only hydrogen and oxygen.
A compound that is always in liquid form.
A compound that does not interact with water.
What is the formula and systematic name of Epsom salts?
MgSO₄·7H₂O, magnesium sulfate heptahydrate
NaCl, sodium chloride
CaCO₃, calcium carbonate
KNO₃, potassium nitrate
What is a physical characteristic that sometimes changes when a hydrate has been heated?
Color
Odor
Taste
Density
What is the prefix for a hydrate with 5 water molecules?
Penta-
Hexa-
Tetra-
Hepta-
Which prefix is used for a hydrate with 3 water molecules?
Tri-
Di-
Tetra-
Mono-
What is the prefix for a hydrate with 1 water molecule?
Mono-
Di-
Tri-
Tetra-
If a hydrate contains 7 water molecules, which prefix should be used?
Hepta-
Octa-
Hexa-
Penta-
Which prefix corresponds to a hydrate with 8 water molecules?
Octa-
Hepta-
Nona-
Deca-
What is the prefix for a hydrate with 2 water molecules?
Di-
Mono-
Tri-
Tetra-
What is the prefix for a hydrate with 4 water molecules?
Tetra-
Penta-
Hexa-
Hepta-
What is the primary difference between naming ionic compounds and molecular or covalent compounds?
Ionic compounds use prefixes, molecular compounds do not.
Molecular compounds use prefixes to indicate the number of atoms, ionic compounds do not.
Both use the same naming rules.
Ionic compounds are always gases.
What two molecular compounds will we ALWAYS use common names for?
Water and carbon dioxide
Ammonia and methane
Water and ammonia
Oxygen and nitrogen
What is ALWAYS the first step in naming a molecular compound?
Write the name of the second element first
Identify the number of atoms of each element
Write the name of the first element in the formula
Use the common name
What are molecular or covalent compounds composed of?
Metals only
Nonmetals only
Metals and nonmetals
Ions
Give the basic format for naming binary molecular compounds:
Prefix + first element + prefix + second element + -ide
First element + second element + -ate
Prefix + second element + prefix + first element + -ite
First element + second element + -ous
Which element is placed first in the compound formula?
The more electronegative element
The element with the higher atomic number
The less electronegative element
The element with the lower atomic number
Match the correct prefix to the number of atoms in a molecular/covalent compound:
1 - mono, 2 - di, 3 - tri, 4 - tetra, 5 - penta, 6 - hexa, 7 - hepta, 8 - octa, 9 - nona, 10 - deca
1 - di, 2 - mono, 3 - tetra, 4 - tri, 5 - hexa, 6 - penta, 7 - octa, 8 - nona, 9 - deca, 10 - hepta
1 - hexa, 2 - penta, 3 - octa, 4 - nona, 5 - deca, 6 - mono, 7 - di, 8 - tri, 9 - tetra, 10 - hepta
1 - deca, 2 - nona, 3 - octa, 4 - hepta, 5 - hexa, 6 - penta, 7 - tetra, 8 - tri, 9 - di, 10 - mono
What do we note when there is only one atom of the first element in a molecular compound?
The prefix "mono-" is always used
The prefix "mono-" is omitted
The prefix "di-" is used
The prefix "tri-" is used
What is the main difference between HCl(g) and HCl(aq)?
HCl(g) is a gas, while HCl(aq) is dissolved in water.
HCl(g) is a solid, while HCl(aq) is a liquid.
HCl(g) is an acid, while HCl(aq) is a base.
HCl(g) is found in food, while HCl(aq) is found in cleaning products.
Which of the following is a common characteristic of acids?
They taste sour.
They feel slippery.
They are always solid at room temperature.
They turn blue litmus paper red.
Where are acids most commonly found in the home?
In cleaning products and some foods.
In electronic devices.
In wooden furniture.
In clothing materials.
What are the two main categories of acids?
Binary acids and oxyacids.
Organic acids and inorganic acids.
Strong acids and weak acids.
Solid acids and liquid acids.
What is the standard form for naming binary acids?
Hydro + base name of nonmetal + ic + acid
Name of metal + oxide
Prefix + element + suffix
Element + acid
What is the standard format for naming oxyacids that have a polyatomic ion that end in -ate?
The acid name is based on the root of the anion with the suffix -ic and the word "acid"
The acid name is based on the root of the anion with the suffix -ous and the word "acid"
The acid name is based on the root of the anion with the prefix hydro- and the suffix -ic
The acid name is based on the root of the anion with the suffix -ate and the word "acid"
What is the standard format for naming oxyacids that have a polyatomic ion that end in -ite?
The acid name is based on the root of the anion with the suffix -ic and the word "acid"
The acid name is based on the root of the anion with the suffix -ous and the word "acid"
The acid name is based on the root of the anion with the prefix hydro- and the suffix -ic
The acid name is based on the root of the anion with the suffix -ite and the word "acid"
What pollutants are emitted from car exhaust and what acids do they form?
Nitrogen oxides, which form nitric acid
Sulfur oxides, which form sulfuric acid
Carbon dioxide, which forms acetic acid
Methane, which forms hydrochloric acid
What pollutants are emitted from power plants and what acid does it form?
Sulfur oxides, which form sulfuric acid
Nitrogen oxides, which form nitric acid
Carbon monoxide, which forms carbonic acid
Ozone, which forms phosphoric acid
What kinds of problems are associated with Acid Rain?
Damage to aquatic ecosystems, soil degradation, and harm to buildings and monuments
Increase in atmospheric oxygen, improved plant growth, and cleaner air
Decrease in soil nutrients, increase in crop yield, and reduction in water pollution
Enhanced photosynthesis, reduced erosion, and improved water quality
What is the pH of normal rain?
About 5.6
About 7.0
About 3.0
About 9.0
What is the correct name for the compound H₂SO₃ (aq)?
Sulfurous acid
Sulfuric acid
Hydrosulfuric acid
Sulfuric oxide
What is the correct name for the compound Al(NO₃)₃?
Aluminum nitrate
Aluminum nitrite
Aluminum trinitrate
Aluminum nitride
What is the correct name for the compound Ni₂(SO₄)₃?
Nickel(III) sulfate
Nickel(II) sulfate
Nickel sulfate
Nickel trisulfate
What is the correct name for the compound NO?
Nitric oxide
Nitrogen dioxide
Nitrous oxide
Nitrogen monoxide
What is the correct name for the compound NO₂?
Nitrogen dioxide
Nitric oxide
Nitrous oxide
Nitrogen monoxide
What is the correct name for the compound B₂H₆?
Diborane
Borane
Boron hexahydride
Diboron hexahydride
What is the correct name for the compound HClO₄?
Perchloric acid
Chloric acid
Hypochlorous acid
Chlorous acid
Which of the following best defines "formula mass"?
The sum of the atomic masses of all atoms in a chemical formula
The mass of one mole of a substance
The mass of a single atom
The number of molecules in a mole
Which of the following best defines "molar mass" (mole mass)?
The mass of one mole of a substance
The sum of the atomic numbers in a formula
The number of atoms in a molecule
The volume of one mole of a gas
Which of the following best defines "molecular weight"?
The sum of the atomic masses of all atoms in a molecule
The weight of a single atom
The number of molecules in a sample
The mass of a mole of ions
What is the basic process for finding the molecular weight (MW) of an ionic compound?
Add the atomic masses of all atoms in the compound
Subtract the atomic masses of all atoms in the compound
Multiply the atomic masses of all atoms in the compound
Divide the atomic masses of all atoms in the compound
How does the mole mass function as a conversion factor?
It allows conversion between grams and moles
It changes the color of a compound
It determines the boiling point of a compound
It measures the temperature of a reaction
What conversion factor is used when converting from mole to molecules?
Avogadro’s number (6.022 x 10^23)
The boiling point of water
The density of the compound
The melting point of the compound
What is the conceptual plan when converting from grams to molecules? Identify what conversion factors will be used (generally such as mole mass or Avogadro’s number) on the arrows.
Grams → Moles (using molar mass) → Molecules (using Avogadro’s number)
Grams → Liters (using density) → Molecules (using boiling point)
Grams → Atoms (using atomic number) → Molecules (using melting point)
Grams → Joules (using specific heat) → Molecules (using temperature)
What does a chemical formula represent?
The types and numbers of atoms in a compound
The boiling point of a compound
The color of a compound
The taste of a compound
What is a CFC?
Chlorofluorocarbon
Carbon Fluoride Compound
Chemical Formula Compound
Chlorine Free Compound
Which of the following best defines mass percent (composition)?
The ratio of the mass of one element to the total mass of the compound, multiplied by 100
The number of atoms in a molecule
The total volume of a substance
The density of a compound
What is the equation for Mass % of an element?
(Mass of element in 1 mol of compound / Molar mass of compound) × 100%
(Number of atoms / Avogadro’s number) × 100%
(Volume of element / Total volume) × 100%
(Density of element / Total density) × 100%
How does the mole mass act as a conversion factor?
It allows conversion between mass and number of moles of a substance
It measures the temperature of a substance
It determines the color of a compound
It calculates the speed of a reaction
How can Mass % act as a conversion factor?
By relating the mass of a compound to the volume of a solution
By relating the mass of an element to the total mass of the compound
By converting moles to atoms
By converting temperature to energy
When using mass percent in calculations going from mass of an element to mass of a compound, what assumption can be made?
The compound is always a gas
The mass percent is constant for all compounds
The sample is pure and all of the element is present in the compound
The element is not present in the compound
What is the conceptual plan when going from the mass of a compound to mass of an element in the compound? Give the necessary general conversion factors on the arrows.
Mass of compound → moles of compound → moles of element → mass of element
Mass of compound → volume of compound → mass of element
Mass of compound → temperature → mass of element
Mass of compound → density → mass of element
What is the Conceptual Plan for converting from moles in a chemical formula to moles of an element in that formula? What conversion factor is necessary on the arrow?
Use the ratio of moles of element to moles of compound from the chemical formula
Use the ratio of mass of element to mass of compound
Use the ratio of volume of element to volume of compound
Use the ratio of temperature to pressure
What is the Conceptual Plan for converting from mass in grams of a compound to mass in grams of an element in that compound? What are the general conversion factors on the arrows for each step?
The plan involves converting grams of compound to moles of compound, then to moles of element, and finally to grams of element; the conversion factors are molar mass of compound, mole ratio from the formula, and molar mass of element.
The plan involves converting grams of element to moles of element, then to moles of compound, and finally to grams of compound; the conversion factors are atomic number, Avogadro’s number, and density.
The plan involves converting grams of compound directly to grams of element using only the atomic mass of the element.
The plan involves converting grams of compound to liters of compound, then to liters of element, and finally to grams of element; the conversion factors are molar volume, mole ratio, and density.
Can a chemical formula be determined from mass percent composition alone?
Yes, but only the empirical formula can be determined.
No, mass percent composition is not useful.
Yes, both empirical and molecular formulas can be determined directly.
No, only the molecular formula can be determined.
In order to determine the molecular formula from experimental data, what additional information must be known besides the empirical formula?
The molar mass of the compound
The color of the compound
The boiling point of the compound
The density of the compound
Which of the following is the first step in determining the empirical formula from mass percent data?
Convert the mass percent of each element to grams.
Divide the molar mass by the empirical formula mass.
Multiply the subscripts in the empirical formula by a whole number.
Determine the molecular formula.
Which of the following best describes the process of determining the empirical formula from experimental data?
It involves converting mass percent to moles, finding the simplest whole number ratio, and writing the formula.
It involves measuring the boiling point and melting point.
It involves dissolving the compound in water and measuring pH.
It involves comparing the color of the compound to a standard.
What is the Molecular formula equal to?
The actual number of atoms of each element in a molecule
The simplest whole number ratio of atoms in a compound
The total mass of a compound
The number of moles in a sample
What is the Mole mass equal to?
The mass of one mole of a substance
The number of atoms in a molecule
The ratio of molecular to empirical formula
The number of molecules in a sample
