Deck 5: Chemical Accounting

Question 1

When the equation below is balanced, the coefficient of sodium cyanide is: NaCN + H₂SO₄ → Na₂SO₄ + HCN

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

Answer 1

2

Question 2

When the equation below is balanced, the coefficient of copper(II) nitrate is: Cu + AgNO₃ → Cu(NO₃)₂ + Ag

A) 0
B) 1
C) 2
D) 3

Answer 2

1

Question 3

Which one of the following reactions is NOT balanced?

A) 2 CO + O₂ → 2 CO₂
B) 2 SO₂ + O₂ → 2 SO₃
C) 2 KNO₃ + 10 K → 5 K₂O + N₂
D) SF₄ + 3 H₂O → H₂SO₃ + 4 HF

Answer 3

2 KNO₃ + 10 K → 5 K₂O + N₂

Question 4

Octane (C₈H₁₈ ) reacts with oxygen (O₂) to form carbon dioxide (CO₂) and water (H₂O). When the equation below is balanced, the coefficient of octane is: C₈H₁₈ + O₂ → CO₂ + H₂O

A) 8
B) 25
C) 2
D) 16

Question 5

When the equation below is balanced, the coefficient of aluminum chloride is: AlCl₃ + H₂SO₄ → Al₂(SO₄)₃ + HCl

A) 2
B) 3
C) 1
D) 6

Question 6

Propane (C₃H₈ ) reacts with oxygen (O₂) to form carbon dioxide (CO₂) and water (H₂O). When the equation below is balanced, the coefficient of water is: C₃H₈ + O₂ → CO₂ + H₂O

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

Question 7

The following reaction is important in the removal of sulfur dioxide, a major source of acid rain, from the smokestacks of coal burning power plants. When the equation below is balanced, the coefficient of calcium sulfate (commonly called "gypsum") is: CaO + SO₂ + O₂ → CaSO₄

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

Question 8

Tin was among the first metals used by humans. Elemental tin is produced by heating tin(IV) oxide, the principal ore of tin, with carbon. The products of this reaction are tin and carbon dioxide. When the equation is written and balanced, the coefficient of carbon is

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

Question 9

Solid lithium hydride reacts with water to form aqueous lithium hydroxide and hydrogen gas. When this equation is written and balanced, the coefficient of lithium hydride is

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

Question 10

The following reaction is important in the removal of sulfur dioxide, a major source of acid rain, from the smokestacks of coal burning power plants. When the equation below is balanced, the coefficient of calcium oxide (commonly called "lime") is: CaO + SO₂ + O₂ → CaSO₄

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

Question 11

When the equation below is balanced, the coefficient of copper is: Zn + CuSO₄ → ZnSO₄ + Cu

A) 0
B) 1
C) 2
D) 3

Question 12

Tin was among the first metals used by humans. Elemental tin is produced by heating tin(IV) oxide, the principal ore of tin, with carbon. The products of this reaction are tin and carbon dioxide. When the equation is written and balanced, the coefficient of tin is

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

Question 13

When the equation below is balanced, the coefficient of sulfuric acid, H₂SO₄ is: NaCN + H₂SO₄ → Na₂SO₄ + HCN

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

Question 14

When the equation below is balanced, the coefficient of silver is: Cu + AgNO₃ → Cu(NO₃)₂ + Ag

A) 0
B) 1
C) 2
D) 3

Question 15

When the equation below is balanced, the coefficient of the hydrogen cyanide, HCN, is: NaCN + H₂SO₄ → Na₂SO₄ + HCN

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

Question 16

The following reaction is important in the removal of sulfur dioxide, a major source of acid rain, from the smokestacks of coal burning power plants. When the equation below is balanced, the coefficient of oxygen is: CaO + SO₂ + O₂ → CaSO₄

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

Question 17

Ammonia can be prepared by the reaction of magnesium nitride with water. The products are ammonia and magnesium hydroxide. When the equation is written and balanced, the coefficient of magnesium nitride is

A) 1.
B) 3.
C) 6.
D) 8.

Question 18

When the equation below is balanced, the coefficient of the product is: Fe + O₂ → Fe₂O₃

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

Question 19

When the equation below is balanced, the coefficient of oxygen is: Fe + O₂ → Fe₂O₃

A) 0
B) 1
C) 2
D) 3

Question 20

When the equation below is balanced, the coefficient of silver nitrate is: Cu + AgNO₃ → Cu(NO₃)₂ + Ag

A) 0
B) 1
C) 2
D) 3

Question 21

The explanation of the observations leading to the law of combining volumes is often called "Avogadro's hypothesis." This explanation states that equal volumes of gases at the same temperature and pressure have

A) the same number of molecules.
B) different numbers of molecules.
C) the same reactivity.
D) different energies.

Question 22

Which of the following is correct, according to Avogadro's hypothesis?

A) At 0°C and 1 atm pressure, equal volumes of gases contain equal masses.
B) At 0°C and 1 atm pressure, equal volumes of gases contain the same number of molecules.
C) At 0°C and 1 atm pressure, equal volumes of gases have the same density.
D) At 0°C and 1 atm pressure, 1 L of oxygen gas and 1 L of liquid water contain the same number of molecules.

Question 23

When 2 liter of nitrogen gas reacts with 6 liters of hydrogen gas at constant temperature and pressure, how many liters of ammonia gas will be produced?

A) 2
B) 4
C) 6
D) 8

Question 24

Ammonia can be prepared by the reaction of magnesium nitride with water. The products are ammonia and magnesium hydroxide. When the equation is written and balanced, the coefficient of water is

A) 1.
B) 2.
C) 3.
D) 6.

Question 25

Ammonia can be prepared by the reaction of magnesium nitride with water. The products are ammonia and magnesium hydroxide. When the equation is written and balanced, the coefficient of ammonia is

A) 1.
B) 2.
C) 3.
D) 6.

Question 26

Ammonia can be prepared by the reaction of magnesium nitride with water. The products are ammonia and magnesium hydroxide. When the equation is written and balanced, the coefficient of magnesium hydroxide is

A) 1.
B) 3.
C) 6.
D) 8.

Question 27

When oxygen, O₂, is passed through an electrical spark (lightning is a good natural source of an electrical spark), ozone, O₃, is formed. When the equation is balanced, the coefficient of ozone is

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

Question 28

When 4 liters of nitrogen gas react with 6 liters of hydrogen gas at constant temperature and pressure, how many liters of ammonia gas will be produced?

A) 4
B) 6
C) 8
D) 10

Question 29

A liter of solid carbon and a liter of oxygen gas at the same temperature and pressure react to produce carbon dioxide. Using the law of combining volumes, how many liters of carbon dioxide will be produced?

A) 1
B) 2
C) 3
D) The law of combining volumes applies only to reactions involving all gases.

Question 30

Avogadro's number is

A) 6.02 × 10²³
B) 6.02 × 10^-23
C) 3.02 × 10²⁶
D) 2.06 × 10³²

Question 31

Consider the following equation: 2 Na + 2 H₂O → 2 NaOH + H₂ Identify the product(s) for this reaction.

A) Na
B) Na and H₂O
C) NaOH
D) NaOH and H₂

Question 32

Gay-Lussac's law of combining volumes states that the volumes of reactants and products are in small whole-number ratios. Which of the following is NOT an assumption for the law of combining volumes?

A) The products and reactants must all be gases.
B) The products and reactants must all be at the same temperature.
C) The products and reactants must all be at the same pressure.
D) The products and reactants must all be gases or liquids.

Question 33

The label which indicates that a substance is a gas is

A) (g)
B) (l)
C) (s)
D) (aq)

Question 34

The law of combining volumes applies only to

A) gases.
B) liquids.
C) solids.
D) gases and liquids.

Question 35

When oxygen, O₂, is passed through an electrical spark (lightning is a good natural source of an electrical spark), ozone, O₃, is formed. When the equation is balanced, the coefficient of oxygen is

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

Question 36

In order for the law of combining volumes to apply, all of the following must be the same for all reactants EXCEPT

A) the pressure must be the same.
B) the reactants must be liquids.
C) the temperature must be the same.
D) all reactants must be gases.

Question 37

The observations that gaseous reactants combine to form gaseous products in volume ratios that are simple whole numbers is most directly summarized by which of the following.

A) The Law of Conservation of Mass
B) The Law of Fixed Proportions
C) The Law of Multiple Proportions
D) The Law of Combining Volumes

Question 38

The total number of each type of atom must be the same on both sides of an equation in order to satisfy the

A) Law of Combining Volumes.
B) Law of Conservation of Matter.
C) Law of Constant Composition.
D) Law of Multiple Proportions.

Question 39

When 5 liters of hydrogen gas and 2.5 liter of oxygen gas react to form water at a constant temperature and pressure, how many liters of water vapor (steam) will be formed?

A) 2.5
B) 5
C) 3
D) .5

Question 40

Avogadro's number is big. If you had 6.02 × 10²³ dollars, and could spend it at 1 billion (10⁹) dollars per second for your entire life (≈ 75 years), what approximate percentage of your original money would you have left?

A) 0%
B) 10%
C) 50%
D) ≈ 100%

Question 41

Which of the following contains Avogadro's number of atoms?

A) 15.5 g of phosphorus
B) 39 g of potassium
C) 40 g of bromine
D) 100 g of mercury

Question 42

Joseph Priestley discovered oxygen in 1774 by heating mercury(II) oxide. The compound decomposes into its elements. How much oxygen, O₂, is produced by the decomposition of 25 g of HgO?

A) 1.8 g
B) 3.7 g
C) 5.5 g
D) none of these

Question 43

How many moles of (NH₄)₂S are there in 75 g of (NH₄)₂S?

A) 1.04
B) 1.10
C) 1.50
D) 1.56

Question 44

Which of the following has the same number of atoms as 35.4 g of chlorine?

A) 35.4 g of germanium
B) 19 g of potassium
C) 12 g of carbon
D) 18 g of water

Question 45

Aspirin has a formula C₉H₈O₄. The molar mass of aspirin is

A) 95 g/mole.
B) 180 g/mole.
C) 220 g/mole.
D) 325 g/mole.

Question 46

Nitroglycerin has a formula C₃H₅(NO₃)₃. The molar mass of nitroglycerin is

A) 65 g/mole.
B) 227 g/mole.
C) 309 g/mole.
D) 398 g/mole.

Question 47

The quantitative relationship between reactants and products in a chemical reaction is

A) relative mass.
B) percent yield.
C) molarity.
D) stoichiometry.

Question 48

What is the molar mass of N₂O?

A) 30 g/mole
B) 30 u
C) 44 g/mole
D) 44 u

Question 49

Consider the following equation: N₂ + 3 H₂ → 2 NH₃ Which of the following statements is NOT true for this equation?

A) 3 mole of N₂ reacts with 9 moles of H₂.
B) 1 L of N₂ reacts with 3 L of H₂.
C) 3 gram of N₂ reacts with 9 grams of H₂.
D) 2 molecule of N₂ reacts with 6 molecules of H₂.

Question 50

What is the mass of 0.500 mol of NH₃?

A) 8.50 g
B) 3.40 g
C) 7.50 g
D) 34.0 g

Question 51

In the reaction CH₄ + 2 O₂ → CO₂ + 2 H₂O, how many moles of oxygen are required to burn 8.0 g of methane?

A) 0.5
B) 1.0
C) 2.0
D) 32

Question 52

Which of the following does NOT contain Avogadro's number of particles?

A) 1.0 mole of silver
B) 23 g of sodium
C) 6.02 × 10²³ atoms of aluminum
D) 12 g of water

Question 53

In the reaction CH₄ + 2 O₂ → CO₂ + 2 H₂O, how many moles of oxygen are required to burn 16.0 g of methane?

A) 0.500
B) 1.00
C) 2.00
D) 32.0

Question 54

How many molecules are in 237 g (about a cup) of water?

A) 13.1
B) 4267
C) 6.02 × 10²³
D) 7.92 × 10²⁴

Question 55

How many moles of sulfur atoms are present in 4.00 moles of CS₂?

A) 2.00
B) 4.00
C) 8.00
D) 12.00

Question 56

The formula mass of CO₂ is

A) 28 g/mole.
B) 28 u.
C) 44 g/mole.
D) 44 u.

Question 57

Which of the following contains as many atoms as 18 g of water, H₂O?

A) one mole of nitrogen, N₂
B) three moles of zinc, Zn
C) two moles of sodium chloride, NaCl
D) two moles of nitrogen, N₂

Question 58

Calcium metal reacts with water to form calcium hydroxide and hydrogen gas. How many grams of hydrogen are formed when 0.50 g of calcium are added to water?

A) 0.025 g
B) 0.050 g
C) 0.10 g
D) 0.50 g

Question 59

Acetylene (C₂H₂) burns in pure oxygen with a very hot flame. The products of this reaction are carbon dioxide and water. How much oxygen is required to react with 52.0 g of acetylene?

A) 32.0 g
B) 52.0 g
C) 160. g
D) 240. g

Question 60

What is the molecular mass of N₂O?

A) 30 g/mole
B) 30 u
C) 44 g/mole
D) 44 u

Question 61

A solution contains 20 mL of ethanol in a total volume of 100 mL. The concentration of this solution is

A) 2.0 M.
B) 2.0 % by mass.
C) 20 % by mass.
D) 20 % by volume.

Question 62

A solution that is 1% by mass contains

A) 3 g of solute in 3 kg of solution.
B) 1 g of solute in 100 g of solution.
C) 3 mL of solute in 300 mL of solution.
D) 2 mole of solute in 2 L of solution.

Question 63

A one molar solution is a solution that contains one mole of solute in

A) one mole of solvent.
B) one liter of solution.
C) one kilogram of solvent.
D) one kilogram of solution.

Question 64

A solution that is 1 molar contains

A) six moles of solute in 6 moles of solvent.
B) five moles of solute in 5 moles of solution.
C) six moles of solute in 600 g of solution.
D) four moles of solute in 4 liters of solution.

Question 65

Molarity is a measure of

A) the volume of a solution.
B) the mass of a substance.
C) the ability of a substance to ionize.
D) the concentration of a solute in a solution.

Question 66

What mass of KOH is needed to make 400.0 mL of 0.725 M KOH?

A) 31.0 g
B) 101.7 g
C) 40.6 g
D) 16.3 g

Question 67

A chemist dissolves 9 g of NaCl in 225 mL of water. Water is the

A) solution.
B) solute.
C) solvent.
D) solubility.

Question 68

Atom economy is

A) the calculation of the number of atoms conserved in the desired product rather than in waste.
B) counting the atoms in the starting material and product.
C) having green by-products.
D) having green starting materials.

Question 69

Calculate the number of moles of sodium hydroxide present in 300 mL of a 2.0 M solution of sodium hydroxide.

A) 600 moles of sodium hydroxide
B) 0.60 moles of sodium hydroxide
C) 300 moles of sodium hydroxide
D) 2.0 moles of sodium hydroxide

Question 70

A four molar solution of NaOH in water contains

A) four moles of NaOH per liter of solution.
B) four grams of NaOH per liter of solution.
C) four liters of NaOH per mole of solution.
D) four moles of NaOH per mole of solution.

Question 71

How many mL of a 4.0% NaOH solution do you need to have 16 g of NaOH?

A) 160 mL
B) 250 mL
C) 400 mL
D) 640 mL

Question 72

How many liters of a 0.2 M HCl solution are needed in order to have 1.0 moles of HCl?

A) 0.2 L
B) 0.8 L
C) 5 L
D) 8 L

Question 73

Calculate the number of moles of sodium chloride needed to make 4.0 L of a 3.0 M solution.

A) 12 moles of sodium chloride
B) 3.0 moles of sodium chloride
C) 4.0 moles of sodium chloride
D) 7.0 moles of sodium chloride

Question 74

The molarity of a solution that contains 0.50 moles of NaOH in 200.0 milliliters of water is

A) 0.25 M.
B) 0.5 M.
C) 1.0 M.
D) 2.5 M.

Question 75

Expressing concentrations in terms of molarity is especially convenient since it allows one to count chemical particles by measuring

A) the weights of solutes.
B) the weights of solutions.
C) the volumes of solvents.
D) the volumes of solutions.

Question 76

The molarity of a solution that contains 8.0 g of NaOH in a liter of solution is

A) 0.020 M.
B) 0.20 M.
C) 2.0 M.
D) 0.80 M.

Question 77

The reactants are the starting materials in a reaction.

Question 78

How many liters of a 0.2 M NaOH solution are needed in order to have 1.0 moles of NaOH?

A) 0.2 L
B) 0.8 L
C) 5 L
D) 8 L

Question 79

What is the best way to measure the efficiency of a reaction?

A) experimental yield
B) percent atom economy
C) percent yield
D) theoretical yield

Question 80

The number of moles of NaOH that are in 250 mL of a 3.0 molar solution is

A) 0.25 moles.
B) 0.75 moles.
C) 1.0 moles.
D) 1.5 moles.