Deck 5: Molecules and Compounds

Question 1

The ratio in a chemical formula is a ratio of atoms,not a ratio of masses.

Answer 1

True

Question 2

The subscripts in a chemical formula represent the relative mass of each atom in a chemical compound.

Answer 2

False

Question 3

The subscripts in a chemical formula do not change for a given compound.

Answer 3

True

Question 4

The properties of a compound are an average of the properties of the individual elements.

Question 5

Life could not exist with just 91 elements if they did not combine to form compounds.

Question 6

The law of constant composition states: All samples of a given compound have the same proportions of their constituent elements.

Question 7

Carbon dioxide is an example of a molecular compound.

Question 8

When elements combine to form compounds,their properties only change slightly.

Question 9

Molecular elements do not exist in nature.

Question 10

The formula of a compound comprised of two nitrogen atoms and one oxygen atom should be written properly as ON₂.

Question 11

Ionic compounds always contain positive and negative ions.

Question 12

Although some substances we encounter in our routine lives are elements,most occur in the combined state.

Question 13

The element nitrogen normally exists in nature as a diatomic molecule.

Question 14

SO₂ is an ionic compound.

Question 15

Ionic compounds have a net charge of zero.

Question 16

The basic unit of an ionic compound is called the formula unit.

Question 17

If a chemical reaction produces the molecular element oxygen,the formula of oxygen should be written as O₂ .

Question 18

In ionic compounds the net positive charge always equals the net negative charge.

Question 19

The fact that water has an oxygen-to-hydrogen mass ratio of 8.0 illustrates the law of conservation of mass.

Question 20

Chemical formulas normally list the most metallic elements first.

Question 21

The ionic compound that forms between Mg and O is MgO.

Question 22

The law of constant composition states:

A)Matter cannot be either created or destroyed in a chemical reaction.
B)The nucleus is a dense region of positive charge that always contains protons and neutrons.
C)All samples of a given compound have the same proportions of their constituent elements.
D)All atoms of a given element have a constant composition and are different than atoms of any other element.
E)none of the above

Question 23

Ionic compounds are usually made up of a metal and a nonmetal.

Question 24

The name of KNO₃ is potassium nitratide.

Question 25

The correct name for H₂SO₃ is sulfurous acid.

Question 26

If there are two ions in a series of oxoanions,the one with more oxygen is given the ending "-ite."

Question 27

The correct formula for calcium fluoride is CaF₃.

Question 28

The oxygen-to-hydrogen mass ratio of water is always 8.0 is an example of what fundamental law?

A)Law of Constant Composition
B)Law of Constant Mass Ratio
C)Law of Conservation of Mass
D)Law of Constant Whole Number Ratio
E)none of the above

Question 29

The ionic compound that forms between aluminum and oxygen is AlO.

Question 30

Metal cations that form more than one type of ion are usually found in the section of the periodic table known as the transition metals.

Question 31

The proper name for SF₆ is sulfur tetrafluoride.

Question 32

When elements combine to form compounds:

A)their properties are an average of all elements in the compound.
B)their properties change completely.
C)their properties do not change.
D)their properties are completely random.
E)none of the above

Question 33

Carbonic acid,H₂CO₃ ,contains the carbonate oxyanion.

Question 34

The first chemist to formally state the law of constant composition was:

A)Dalton.
B)Mendeleev.
C)Rutherford.
D)Proust.
E)none of the above

Question 35

If an oxyacid contains the sulfate oxyanion,then this acid has the name sulfurous acid.

Question 36

The proper name for HI is hydroiodic acid.

Question 37

The correct name for HNO₃ is hydronitric acid.

Question 38

The ionic compound MgO is named manganese oxide.

Question 39

The proper name for the acid HF is hydrofluoric acid.

Question 40

The correct formula for sodium permanganate is NaMgO₄.

Question 41

What is the oxygen-to-hydrogen mass ratio for H₂O₂?

A)0.125
B)4
C)8
D)16
E)none of the above

Question 42

Which formula shows the proper use of parentheses?

A)Ca(F)₂
B)Ca(SO₄)
C)(NH₄)₃(PO₄)
D)Ca(NO₃)₂
E)none of the above

Question 43

Which of the following species is a molecular element?

A)neon
B)sodium
C)chlorine
D)carbon dioxide
E)none of the above

Question 44

How many carbon atoms are in the formula Al₂(CO₃)₃?

A)3
B)9
C)1
D)6
E)none of the above

Question 45

What is the oxygen-to-sulfur mass ratio of sulfur dioxide?

A)0.5
B)1.0
C)2.0
D)16
E)none of the above

Question 46

Carbon is considered which of the following?

A)atomic element
B)molecular element
C)molecular compound
D)ionic compound
E)none of the above

Question 47

Carbon monoxide is considered which of the following?

A)atomic element
B)molecular element
C)molecular compound
D)ionic compound
E)none of the above

Question 48

What is the correct formula for a compound that has three oxygen atoms and one sulfur atom?

A)O₃S
B)SO₃
C)3OS
D)SO3
E)none of the above

Question 49

How many of each type of atom are there in the formula Ca₃(PO₄)₂?

A)Ca = 3,P = 1,O = 4
B)Ca = 3,P = 2,O = 4
C)Ca = 3,P = 2,O = 8
D)Ca = 3,P = 1,O = 8
E)none of the above

Question 50

The phosphorous-to-hydrogen mass ratio is 10.2 for a compound.This ratio could correspond to the compound:

A)PH.
B)PH_2.
C)PH_3.
D)PH_6.
E)none of the above

Question 51

How many total atoms are in the formula Al₂(CO₃)₃?

A)8
B)9
C)12
D)14
E)none of the above

Question 52

What is the correct formula of a compound that has ten oxygen atoms and four phosphorus atoms?

A)O₁₀P₄
B)10OP₄
C)4PO₁₀
D)P₄O₁₀
E)none of the above

Question 53

How many oxygen atoms are in the formula Al₂(CO₃)₃?

A)3
B)9
C)1
D)6
E)none of the above

Question 54

How many of each type of atom are there in the formula (NH₄)₂HPO₄?

A)N = 2,H = 9,P = 1,O = 4
B)N = 1,H = 5,P = 1,O = 4
C)N = 2,H = 5,P = 1,O = 4
D)N = 2,H = 8,P = 1,O = 4
E)none of the above

Question 55

Ammonium fluoride is considered which of the following?

A)atomic element
B)molecular element
C)molecular compound
D)ionic compound
E)none of the above

Question 56

Fluorine is considered which of the following?

A)atomic element
B)molecular element
C)molecular compound
D)ionic compound
E)none of the above

Question 57

Which among the following elements does NOT exist as a diatomic molecule in nature?

A)hydrogen
B)nitrogen
C)fluorine
D)neon
E)none of the above

Question 58

Which of the following statements about chemical formulas is FALSE?

A)The subscripts represent the relative number of each type of atom in the compound.
B)The subscripts represent the relative mass of each type of atom in the compound.
C)The subscripts do not change for a given compound.
D)Different compounds made of the same elements have different subscripts.
E)All of the statements are true.

Question 59

Suppose an unknown compound XY has an X-to-Y mass ratio of 4.0.If decomposition of compound XY gives 12.0 grams of X,then how many grams of Y must form?

A)48.0 grams
B)12.0 grams
C)4.0 grams
D)3.0 grams
E)none of the above

Question 60

How many of each type of atoms are there in the formula NH₄C₂H₃O₂?

A)N = 4,H = 7,C = 2,O = 2
B)N = 1,H = 4,C = 2,O = 2
C)N = 1,H = 3,C = 2,O = 2
D)N = 1,H = 7,C = 2,O = 2
E)none of the above

Question 61

What is the correct formula for ammonium hydrogen sulfate?

A)NH₄HSO₄
B)(NH₄)₂HSO₄
C)(NH₄)₂SO₄
D)Am₂HSO₄
E)none of the above

Question 62

A student wrote the formula for the compound aluminum phosphate as AlPO₄ .What is wrong with this formula?

A)The compound is not charge-neutral.
B)Aluminum is a nonmetal so it cannot form an ionic compound.
C)The formula should be Al(PO₄).
D)There cannot be three different atom types in a chemical formula.
E)Nothing is wrong with the formula.

Question 63

What is the name of the compound whose formula is Na₂O?

A)sodium monoxide
B)disodium oxide
C)disodium monoxide
D)sodium oxide
E)none of the above

Question 64

The charge of a vanadium ion in the compound V₂O₅ is:

A)5+
B)2+
C)10+
D)10-
E)none of the above

Question 65

What is the correct formula for potassium dichromate?

A)K(CrO₄)₂
B)KCr₂O₇
C)K₂CrO₄
D)K₂Cr₂O₇
E)none of the above

Question 66

Which formula shown is incorrect for the name given?

A)magnesium nitrite: Mg(NO₂)₃
B)calcium carbonate: CaCO₃
C)aluminum sulfate: Al₂(SO₄)₃
D)sodium hydrogen carbonate: NaHCO₃
E)potassium hydroxide: KOH

Question 67

What is the formula for an ionic compound made of magnesium and sulfur?

A)MgS
B)MgS₂
C)Mg₂S
D)Mg₂S₃
E)none of the above

Question 68

What is the formula for an ionic compound made of barium and nitrogen?

A)Ba₃N₂
B)Ba₂N₃
C)BaN
D)Ba₂N₄
E)none of the above

Question 69

What is the name of Ca(NO₃)₂?

A)calcium dinitrite
B)calcium nitrate
C)calcium nitride
D)calcium nitrite
E)none of the above

Question 70

What is the name of the ionic compound made of beryllium and chlorine?

A)beryllium(II)chloride
B)beryllium dichloride
C)beryllium chloride
D)monoberyllium dichloride
E)none of the above

Question 71

What is the formula for the acetate polyatomic ion?

A)C₃H₂O₃^-
B)C₂H₃O₂^2-
C)C₂H₃O₂^-
D)C₂H₃O^-
E)none of the above

Question 72

What is the formula for an ionic compound made of aluminum and oxygen?

A)AlO₂
B)Al₂O₃
C)Al₃O₂
D)AlO
E)none of the above

Question 73

Which of the following is a molecular compound?

A)barium sulfide
B)calcium acetate
C)potassium hydroxide
D)nitrogen monoxide
E)none of the above

Question 74

What is the name of CoS?

A)cobalt(II)sulfide
B)cobalt sulfide
C)cobalt monosulfide
D)cobaltous sulfur
E)none of the above

Question 75

The ionic compound that forms between potassium and oxygen is:

A)K₂O.
B)KO.
C)KO_2.
D)K₂O_2.
E)none of the above

Question 76

What is the formula for an ionic compound made of carbon and oxygen?

A)CO₂
B)C₂O
C)CO
D)CO₃
E)Carbon and oxygen do not form an ionic compound.

Question 77

Which formula shown is incorrect for the name given?

A)strontium carbonate: SrCO₃
B)ammonium cyanide: NH₄CN
C)potassium acetate: KC₂H₃O₂
D)calcium nitrate: Ca(NO₃)₂
E)lithium sulfate: LiSO₄

Question 78

Which metal atom below cannot form a cation of several different charges?

A)Cr
B)Mn
C)Fe
D)Ba
E)none of the above

Question 79

What is the name of the compound made from lithium and oxygen?

A)lithium dioxide
B)lithium(I)oxide
C)oxygen lithide
D)lithium oxide
E)none of the above

Question 80

The formula for potassium chlorate is KClO₃.The formula for magnesium chloride is MgCl₂.What is the formula for magnesium chlorate?

A)MgClO₃
B)Mg₂ClO₃
C)Mg(ClO₃)₂
D)Mg₂(ClO₃)₃
E)none of the above