Deck 9: How Chemicals React

Question 1

Four units of monoatomic substance A combines with one unit diatomic substance B to make the triatomic substance C. Two units of triatomic substance C combine with one unit of diatomic substance B to make substance D. Place the letter of each substance next to the symbol that best describes its atomic or molecular structure.

A)A, D, B, C
B)C, A, B, D
C)D, B, A, C
D)B, D, A, C

Answer 1

D, B, A, C

Question 2

Steel wool wetted with vinegar is sealed within a balloon inflated with air. After several hours, what happens to the volume of the balloon?

A)The balloon inflates.
B)The balloon deflates.
C)The balloon dissolves.
D)Nothing because the vinegar is acting on the steel wool, not upon the balloon.

Answer 2

The balloon deflates.

Question 3

For the following balanced reaction, which of the following is a gas? 2 Na_(l) + Cl_2(g) → 2 NaCl_(s)

A)Na
B)2 Na
C)Cl₂
D)Cl
E)NaCl

Answer 3

Cl₂

Question 4

Given the following generic chemical reaction, which is the reactant? X → Y

A)Y is the reactant.
B)X is the reactant.
C)→ is the reactant.
D)Both X and Y are the products.
E)Both X and Y are the reactants.

Question 5

Given the following generic chemical reaction, which is the product? X → Y

A)Y is the product.
B)X is the product.
C)→ is the product.
D)Both X and Y are the products.
E)Both X and Y are the reactants.

Question 6

What is a chemical equation?

A)It is a shorthand notation for illustrating a chemical reaction.
B)It is the sum of the masses of the products and reactants.
C)It is the chemical combination of equal numbers of reactants and products.
D)It is a picture of the atoms undergoing a chemical equalization.
E)It is any type of reaction that takes place at the equator.

Question 7

What is wrong with the following depiction of a chemical reaction?

A)These boxes contain only molecules but no atoms.
B)One box contains more molecules than the other.
C)One box contains more atoms than the other.
D)all of the above

Question 8

In a chemical equation the coefficients ________.

A)of the reactants should always sum up to those of the products
B)appear as subscripts
C)appear before the chemical formulas
D)Two of the above are correct.

Question 9

What coefficient is needed in front of the O₂ molecule to balance the following equation?

A)8
B)13
C)5
D)1

Question 10

Balance the following chemical equation. ____ N₂ + ____ H₂ → ____ NH₃

A)1, 3, 2
B)1, 2, 3
C)3, 2, 1
D)2, 6, 4
E)1/2, 3/2, 1

Question 11

What is a chemical reaction?

A)when one or more new compounds are formed by rearranging atoms
B)when a new element is formed by rearranging nucleons
C)when two solids mix together to form a heterogeneous mixture
D)when two liquids mix to form a homogeneous mixture
E)when a liquid undergoes a phase change and produces a solid

Question 12

Steel wool wetted with vinegar is stuffed into a narrow mouth round glass bottle. A rubber balloon is then sealed over the mouth of the bottle. After several hours, the balloon inflates into the bottle in an inverted manner. What happened?

A)Vinegar fumes are diamagnetic and as they accumulate above the liquid the steel wool is attracted thus inflating the balloon into the mouth of the bottle in an inverted manner.
B)The caustic vinegar fumes get past the steel wool and deteriorate the balloon, which begins to sag into the bottle and inflate it in an inverted manner.
C)The vinegar reacts with the steel wool by absorbing oxygen within the bottle thus decreasing the pressure. The greater outside pressure causes the balloon to inflate in an inverted manner.
D)False! The balloon inflates above the mouth of the bottle because the reaction between the vinegar and steel wool produces a gas which is forced upward because of increased pressure inside the sealed bottle.

Question 13

For the following balanced equation, which has the highest coefficient? 4 H₂ + 2 C → 2 CH₄

A)H₂
B)C
C)CH₄
D)H₄
E)none of the above

Question 14

A friend argues that if mass were really conserved he would never need to refill his gas tank. What explanation do you offer your friend?

A)The atoms (mass)of gasoline are converted into energy by the engine according to E=m .
B)The Law of Conservation of Mass does not apply to reactions involving combustion or explosion of matter.
C)The atoms (mass)of gasoline are converted into exhaust fumes.
D)The oil companies make gasoline in a way that it gets used up so that we are always required to replenish it.

Question 15

Balance the following equation. ____ NO → ____ N₂O + ____ NO₂

A)3, 1, 1
B)3, 0, 0
C)4, 4, 8
D)1, 2, 4
E)6, 2, 1

Question 16

Which of the following is a correctly balanced equation?

A)P₄ + 6 H₂ → 4 PH₃
B)1 P₄ + 6 H₂ → 4 PH₃
C)0 P₄ + 6 H₂ → 4 PH₃
D)2 P₄ + 12 H₂ → 8 PH₃
E)P₄ + 3 H₂ → PH₃

Question 17

Which equations are balanced?
a)Mg (s)+ 2HCl (aq)→ (aq)+ (g)
b)3Al (s)+ 3 (l)→ (s)
c)2HgO (s)→ 2 Hg (l)+ (g)

A)Only equation "c" is balanced.
B)Equations "a" and "c" are balanced.
C)Equations "b" and "c" are balanced.
D)All of them are balanced.

Question 18

For the following balanced reaction, which of the following is a solid? 2 Na_(l) + Cl_2(g) → 2 NaCl_(s)

A)Na
B)2 Na
C)Cl₂
D)Cl
E)NaCl

Question 19

Balance these equations. ____ (g)+ ____ (g)→ ____ N (g)

A)2, 2, 3
B)2, 2, 5
C)3, 3, 2
D)3, 1, 2

Question 20

What coefficients balance the following equation? ____ (s)+ ____ (g)→ ____ P (g)

A)4, 2, 3
B)1, 6, 4
C)1, 4, 4
D)2, 10, 8

Question 21

The following diagram depicts the reaction between gaseous oxygen, , and gaseous hydrogen, , to form water vapor, O. What molecules and how many of them should be drawn in the empty box? How many grams of water are formed under these conditions? How many grams of which chemical remain unreacted?

A)five molecules in empty box; 9 grams of O + 0.5 grams of
B)five molecules in empty box; 9 grams of O + 8 grams of
C)five O molecules in empty box; 11.3 grams of O + 5.7 grams of O
D)ten molecules in empty box; 9 grams of O + 8 grams of

Question 22

The atomic masses appearing in the periodic table are ________.

A)absolute masses
B)relative masses
C)standard deviation masses
D)formula masses

Question 23

Which equation best describes the reaction represented in the illustration above?

A)2 + 2 + → 2 + 2
B)2 + 2 + → 2 + 2 DBA
C)2 + 2 + → 2 + 2
D)2 + 2 + → 2 + 2

Question 24

If the relative mass of a hydrogen atom is 1/4 that of a helium atom, how many helium atoms would you need to equal the mass of 200 hydrogen atoms?

A)50
B)200
C)800
D)4
E)100

Question 25

Which is greater: 1.01 amu of hydrogen or 1.01 grams of hydrogen?

A)1.01 amu of hydrogen is greater than 1.01 grams of hydrogen.
B)1.01 grams of hydrogen is greater than 1.01 amu of hydrogen
C)1.01 grams of hydrogen and 1.01 amu of hydrogen have the same mass.
D)Not enough information information is provided.

Question 26

If the relative mass of a hydrogen atom is 1/4 that of a helium atom, how many hydrogen atoms would you need to equal the mass of four helium atoms?

A)16
B)4
C)1/4
D)25
E)6.022 × 10²³

Question 27

How many oxygen molecules are needed to make 10 carbon dioxide molecules according to the following balanced chemical equation? 2 CO + O₂ → 2 CO₂

A)5
B)1
C)4
D)10
E)2

Question 28

The reactants shown schematically below represent iron oxide, and carbon monoxide, CO. Which of the following is the correct full balanced chemical equation for what is depicted?

A) + 3 CO → 2 Fe + 3
B) + 3 CO → 3 FeO + 2 C
C) + 3 CO → 3 Fe + 2C
D) + 3 CO → 2 Fe + 3 O

Question 29

If it takes three carbon atoms to equal the mass of one chlorine atom, what mass of chlorine do you need to equal the number of atoms in one kilogram of carbon?

A)1/3 of a kg
B)30 kg
C)1 kg
D)3 kg
E)6 kg

Question 30

If it takes 200 golf balls to equal the mass of four bowling balls, what is the relative mass of bowling balls to golf balls?

A)1/50
B)1/20
C)20 times
D)100 times
E)6.022 × 10²³

Question 31

The above diagram represents a chemical reaction where the box before the arrow shows the reactants and the box after the arrow shows the products. How many diatomic molecules are represented?

A)1
B)2
C)3
D)4

Question 32

If it takes three golf balls to equal the mass of one tennis ball, what mass of tennis balls do you need to equal the number of golf balls in one kilogram of golf balls?

A)1/3 of a kg
B)30 kg
C)1 kg
D)3 kg
E)6 kg

Question 33

If the relative mass of a pingpong ball is 1/20 that of a golf ball, how many golf balls would you need to equal the mass of 200 Ping-Pong balls?

A)10
B)200
C)100
D)20
E)6.022 × 10²³

Question 34

What is the formula mass of sulfur dioxide, S ?

A)about 16 amu
B)about 32 amu
C)about 60 amu
D)about 64 amu

Question 35

Is it possible to have a macroscopic sample of oxygen that has a mass of 14 atomic mass units?

A)Yes, but it would need to be made of oxygen atoms that each had less than the normal number of neutrons.
B)No, this is less than than the mass of a single oxygen atom.
C)Yes, but it would have the same density as nitrogen.
D)No, because oxygen is a gas at room temperature.

Question 36

Gas A is composed of diatomic molecules (two atoms per molecule)of a pure element. Gas B is composed of triatomic molecules (three atoms per molecule)of another pure element. A volume of gas B is found to be three times more massive than an equal volume of gas A. How does the mass of an atom of gas B compare with the mass of an atom of gas A?

A)An atom of gas B is six times the mass of an atom of gas A.
B)An atom of gas B is three times the mass of an atom of gas A.
C)An atom of gas B is two times the mass of an an atom of gas A.
D)An atom of gas B is equivalent to the mass of an atom of gas A.

Question 37

What are the formula masses of water, O; propene, ; and 2-propanol, O?

A)water: 18 amu; propene: 40 amu; 2-propanol: 58 amu
B)water: 18 amu; propene: 42 amu; 2-propanol: 62 amu
C)water: 18 amu; propene: 42 amu; 2-propanol: 60 amu
D)water: 18 amu; propene: 44 amu; 2-propanol: 64 amu

Question 38

If it takes 20 beryllium atoms to equal the mass of two krypton atoms, what is the relative mass of beryllium compared to krypton?

A)1/10
B)1/20
C)40 times
D)100 times
E)10 times

Question 39

If the relative mass of a pingpong ball is 1/20 that of a golf ball, how many Ping-Pong balls would you need to equal the mass of two golf balls?

A)40
B)20
C)24
D)100
E)6.022 × 10²³

Question 40

Why is it important for a chemist to know the relative masses of atoms?

A)There are not that many different kinds of atoms and so it's important to know how they relate to one another.
B)It provides information about how many atoms two samples have relative to each other
C)It provides an indication of how the different atoms will interact
D)Because the mass of an atom is directly related to its chemical properties.

Question 41

How many grams of water can be formed from the reaction between 10 grams of oxygen and 1 gram of hydrogen?

A)11 grams of water are formed since mass must be conserved.
B)10 grams of water are formed since you can't get a greater mass of water produced than oxygen reacting.
C)9 grams of water are formed because oxygen and hydrogen react in an 8:1 ratio.
D)No water is formed because there is insufficient hydrogen to react with the oxygen.

Question 42

What is the formula mass of a molecule of CO₂?

A)44 amu
B)56 amu
C)58.9 amu
D)118 amu
E)none of the above

Question 43

The following diagrams depict the reaction between gaseous chlorine, , and gaseous hydrogen, , to form gaseous hydrogen chloride, HCl. What should be drawn in the empty box and how many grams of products are formed?

A)five molecules in empty box; 37 grams of HCl + 36 grams of
B)five molecules in empty box; 71 grams of HCl + 1 gram of
C)five HCl molecules in empty box; 50 grams of HCl + 22 grams of HCl
D)five molecules in empty box; 71 grams of HCl + 1 gram of

Question 44

What is the number of moles of H₂O produced if you combust 0.5 mole of CH₄ according to the following balanced equation? CH₄ + 2 O₂ → CO₂ + 2 H₂O

A)2 moles
B)4 moles
C)6 moles
D)8 moles
E)1 mole

Question 45

The relative mass of carbon is 3/8 that of an oxygen molecule. How many grams of carbon are needed to have the same number of particles as found in 32 grams of oxygen molecules?

A)12 g
B)32 g
C)3 g
D)8 g
E)3/8 g

Question 46

How many grams of water, H₂O, can be produced by the reaction of 8 grams of oxygen, O₂, and 8 grams of hydrogen, H₂?

A)16 grams
B)10 grams
C)9 grams
D)8 grams

Question 47

You are given two samples of elements, and each sample has a mass of 10 grams. If the number of atoms in each of these samples is the same, what must be true of the two elements?

A)The density of the two elements are the same.
B)The elements are likely be located in the same position in the periodic table.
C)Their spectral patterns will likely be identical.
D)all of the above

Question 48

According to the following balanced chemical equation, if you want to generate two moles of H₂O, how many moles of O₂ do you need? 2 H₂ + O₂ → 2 H₂O

A)1
B)2
C)1/2
D)4
E)6.022 × 10²³

Question 49

How does formula mass differ from atomic mass?

A)They represent the same thing.
B)The formula mass of a substance is the sum of the atomic masses of the elements is its chemical formula. The atomic mass is the mass of a single atom.
C)The atomic mass of a substance is the sum of the formula masses of the elements is its chemical formula. The atomic mass is the mass of a single atom.
D)The formula mass is the mass of the chemical formula and the atomic mass is the mass of the molecule.

Question 50

How many grams of water, H₂O, can be produced from the reaction of 25.0 grams of hydrogen, H₂, and 225 grams of oxygen, O₂?

A)250 grams
B)225 grams
C)200 grams
D)25 grams

Question 51

What is the mass of one mole of H₂?

A)2 g
B)1 g
C)20 g
D)6.022 × 10²³ g
E)none of the above

Question 52

Fourteen grams of nitrogen, N₂, (N, atomic mass 14 amu)contains ________.

A)1 mole of nitrogen atoms
B)0.5 moles of nitrogen atoms
C)0.25 moles of nitrogen atoms
D)Not enough information is given

Question 53

According to the following balanced chemical equation, if you want to generate two moles of H₂O , how many molecules of O₂ do you need? 2 H₂ + O₂ → 2 H₂O

A)1
B)2
C)1/2
D)4
E)6.022 × 10²³

Question 54

What is the formula mass of a molecule of C₆H₁₂O₆?

A)180 amu
B)24 amu
C)29 amu
D)168 amu
E)none of the above

Question 55

According to the following balanced chemical equation, if you want to generate two moles of H₂O how many grams of O₂ do you need? 2 H₂ + O₂ → 2 H₂O

A)32
B)16
C)8
D)4
E)6.022 × 10²³

Question 56

How is Avogadro's number related to the numbers on the periodic table?

A)The atomic mass listed is the mass of Avogadro's number's worth of atoms.
B)The masses are all divisible by Avogadro's number, which gives you the weight of one mole.
C)The periodic table tells you the mass of one atom. From that, and Avogadro's number you know the number of moles.
D)The periodic table only gives us atomic numbers, not atomic mass.
E)The mass listed is Avogadro's number.

Question 57

What is the number of moles of H₂O produced if you combust one mole of CH₄ according to the following balanced equation? CH₄ + 2 O₂ → CO₂ + 2 H₂O

A)2 moles
B)4 moles
C)6 moles
D)8 moles
E)1 mole

Question 58

Which of the following has the greatest number of particles?

A)1 mole of Na
B)22.990 g of Na
C)1 mole of Be
D)9.012 g of Be
E)All are the same.

Question 59

Which of the following has the greatest mass?

A)1 mole of Pb
B)1 mole of H₂
C)1 mole of Be
D)1 mole of Na
E)All have the same mass.

Question 60

Seven grams of nitrogen, N₂, (N, atomic mass 14 amu)contains ________.

A)1 mole of nitrogen atoms
B)0.5 moles of nitrogen atoms
C)0.25 moles of nitrogen atoms
D)Not enough information is given

Question 61

Which has more atoms: 17.031 g of ammonia, N (17.031 amu), or 72.922 g of hydrogen chloride, HCl (36.461 amu)?

A)17.031 g of N has more atoms than 72.922 g of HCl
B)72.922 g of HCl has more atoms than 17.031 g of N
C)72.922 g of HCl and 17.031 g of N have about the same number of atoms.
D)Not enough information is given.

Question 62

Two amu equals how many grams? (1 amu = 1.661 × 10^-24 g)

A)2 grams
B)1.661 × grams
C)3.322 × grams
D)1.204 × grams

Question 63

Three identical candles are placed in the jars shown below and lit at the same time. Jar x is left open while jars y and z are sealed with lids. The candle in which jar goes out first? x y z

A)The candle in jar x will go out first.
B)The candle in jar y will go out first.
C)The candle in jar z will go out first.
D)All the candles go out at the same time.

Question 64

Assume air has an average molar mass of 28 grams/mole, and determine how many moles of air molecules there are 1.0 liters of air, which contains 1.26 grams of air molecules.

A)28 moles
B)0.45 mole
C)0.045 mole
D)22.4 moles

Question 65

What is the mass of a water molecule, O, in atomic mass units?

A)2 amu
B)3 amu
C)16 amu
D)18 amu

Question 66

Two candles of the same mass, one wide and short and the other thin and tall, are placed in identical jars as shown below and lit at the same time. Lids are then placed on each jar. Which candle goes out first?

A)the short candle
B)the tall candle
C)Both candles go out at the same time.
D)There is no way to know which candle will go out first.

Question 67

What is the mass of an oxygen atom, O, in grams? (1 amu = 1.661 × 10^-24 g)

A)16 grams
B)1.661 × grams
C)2.66 × grams
D)none of the above

Question 68

Which has the greater mass, 1.204 × molecules of molecular hydrogen, , or 1.204 × molecules of water, O?

A)1.204 × molecules of molecular hydrogen has a greater mass than 1.204 × molecules of water
B)1.204 × molecules of water has a greater mass than 1.204 × molecules of molecular hydrogen.
C)The mass of this many molecules of water and molecules are molecular hydrogen are the same.
D)Not enough information is provided.

Question 69

What is the mass of an oxygen atom, O, in atomic mass units?

A)12 amu
B)16 amu
C)18 amu
D)32 amu

Question 70

What is the mass of a water molecule, O, in grams? (1 amu = 1.661 × 10^-24 g)

A)18 grams
B)1.661 × grams
C)2.99 × 10^-23 grams
D)none of the above

Question 71

A 1.00 carat pure diamond has a mass of 0.20 grams. How many carbon atoms are there within this diamond?

A)6.0 × carbon atoms
B)2.0 × carbon atoms
C)1.0 × carbon atoms
D)6.0 × carbon atoms

Question 72

How many molecules of aspirin (formula mass aspirin = 180.0 amu)are there in a 0.250-gram sample?

A)6.02 ×
B)8.36 ×
C)1.51 ×
D)More information is needed.

Question 73

Which has the greatest number of molecules?

A)28 g of nitrogen,
B)32 g of oxygen,
C)32 g of methane, C
D)38 g of fluorine,

Question 74

Which has the greatest number of atoms?

A)28 g of nitrogen,
B)32 g of oxygen,
C)16 g of methane, C
D)38 g of fluorine,

Question 75

What is the number of molecules of O₂ consumed if you combust one mole of CH₄ according to the following balanced equation? CH₄ + 2 O₂ → CO₂ + 2 H₂O

A)1 molecule
B)2 molecules
C)6.022 × 10²³ molecules
D)1.204 × 0²⁴ molecules
E)1 g of molecules

Question 76

There are 1000 liters in 1 cubic meter and 1000 grams in 1 kilogram. How many grams of air are there in 1.00 liter of air? (Assume a density of 1.25 kg/ .)

A)0.00125 gram
B)0.125 gram
C)1.25 grams
D)12.5 grams

Question 77

Which has more atoms: 64.058 g of sulfur dioxide, S (64.058 amu), or 72.922 g of hydrogen chloride, HCl (36.461 amu)?

A)64.058 g of S has more atoms than 72.922 g of HCl
B)72.922 g of HCl has more atoms than 64.058 g of S
C)72.922 g of HCl and 64.058 g of S have about the same number atoms.
D)Not enough information is given.

Question 78

How many grams of gallium are there in a 145 gram sample of gallium arenside, GaAs?

A)74.9 g
B)69.7 g
C)145 g
D)6.02 × 10²³ g

Question 79

What is the number of grams of CO₂ produced if you combust 0.50 mole of CH₄ according to the following balanced equation? CH₄ + 2 O₂ → CO₂ + 2 H₂O

A)22 g
B)10 g
C)44 g
D)32 g
E)1 g

Question 80

Small samples of oxygen gas needed in the laboratory can be generated by any number of simple chemical reactions, such as 2 KCl (s)→ 2 KCl (s)+ 3 (g)
What mass of oxygen (in grams)is produced when 122.6 g of KCl (formula mass = 122.6 amu)takes part in this reaction?

A)32.00 grams
B)48.00 grams
C)96.00 grams
D)More information is needed.