Deck 3: Molecules, Moles, Chemical Equations

Question 1

Which of the following statements is not true?

A)Biomass is formed by the conversion of carbon dioxide and water into sugars.
B)The potential energy in biomass can be transformed into mechanical usages.
C)Biomass is a renewable energy source.
D)The breakdown of sugars in biomass releases H₂.

Answer 1

The breakdown of sugars in biomass releases H₂.

Question 2

Spectator ions do not participate in a chemical reaction.

Answer 2

True

Question 3

A solution of 2.5 M Ba²⁺can be prepared by dissolving 583 g of barium sulfate in one liter of water.

Answer 3

False

Question 4

30 moles of hydrogen and 14 moles of oxygen should react to produce 252 g of water and 2 g of hydrogen.

Question 5

The law of conservation of matter can be interpreted correctly to mean that atoms of one element can neither be created nor be destroyed in a chemical reaction.

Question 6

There are eight oxygen atoms in one molecule of calcium phosphate.

Question 7

Which of the following statements is true of the reaction between KCl(aq)and AgNO ₃ (aq)?

A)One mole of KCl and two moles of AgNO ₃ react without excess remaining.
B)Two moles of KCl react with excess AgNO ₃ to form four moles of AgCl.
C)These two compounds react to form solid AgCl and aqueous KNO ₃ .
D)Chloride is a spectator ion.

Question 8

In the given equation, which of the following species is classified as a spectator ion? AgNO ₃ (aq)+ KCl(aq)→ AgCl(s)+ KNO ₃ (aq)

A)Ag ¹⁺ (aq)
B)NO ₃ ^{1 −} (aq)
C)AgCl(s)
D)Cl ^{1 −} (aq)

Question 9

Potassium permanganate is a soluble salt.

Question 10

Silver chloride is a soluble salt.

Question 11

Chemical equations are written to express the products of a reaction.

Question 12

Barium sulfate is a strong electrolyte.

Question 13

The potential of biomass is related to the enormous amounts of solar energy impinging on the earth every second.

Question 14

The following reaction represents the complete combustion of heptane:
C ₇ H ₁₆ + 11O ₂ → 7CO ₂ + 8H ₂ O

Question 15

In an equation, four moles of hydrogen react with a mole of oxygen to produce two moles of water.

Question 16

In the given equation, which of the following species is classified as a spectator ion? CaCl ₂ (aq)+ NaHCO ₃ (aq)→ CaCO ₃ (s)+ NaCl(aq)+ HCl(aq)

A)Na ¹⁺ (aq)
B)CO ₃ ^{2 −} (aq)
C)CaCO ₃ (s)
D)Ca ²⁺ (aq)

Question 17

The correct physical state subscript for substances dissolved in water is _(w).

Question 18

Sodium nitrate is a strong electrolyte.

Question 19

Acids and bases react to give noxious gases and oxides.

Question 20

A major challenge for the long-term utility of biomass as an energy solution is:

A)creating sugars from carbon dioxide and water.
B)transforming biomass energy into high-energy-density fuels.
C)the production of fixed nitrogen.
D)degrading soil quality.

Question 21

Which of the following illustrates the balanced reaction of ethyl alcohol with an excess of oxygen to form carbon dioxide and water?

A)C₂H₅OH(l)+ 3O₂(g)→ 2CO₂(g) + 3H₂O(l)
B)3C₂H₅OH(l)+ 7O₂(g)→ 6CO₂(g)+ 9H₂O(l)
C)C₂H₅OH(l) + 2O₂(g)→ 3CO₂(g) + 3H₂O(l)
D)3C₂H₅OH(l)+ 3O₂(g) → 2CO₂(g)+ 6H₂O(l)

Question 22

If the solubility of NaCl in water is 35.7 g NaCl per 100 g H ₂ O, what is the minimum volume of water needed to dissolve 100 g of the salt?

A)36 mL
B)140 mL
C)280 mL
D)661 mL

Question 23

How many helium atoms are present in 3.0 × 10 ^{− 2} moles of He(g)?

A)5.6 × 10²¹
B)1.8 × 10²²
C)4.5 × 10²¹
D)1.2 × 10 ²⁵

Question 24

Which of the following may be classified as an example of an acid-base reaction?

A)HCl + NaOH → H₂O + NaCl
B)Ca(NO₃)₂+ H₂SO₄→ CaSO₄+ HNO₃
C)KClO₄+ NaF → NaClO₄+ KF
D)HCOOH + NH₄Cl → NH₄COOH + HCl

Question 25

A "neon" sign contains 2.4 × 10 ² mL of argon. Assuming that the gas is at standard temperature and pressure, there is 1.00 mole of gas per 22.4 L of volume. How many argon atoms are present in this sign?

A)6.45 × 10²¹
B)2.8 × 10²²
C)3.2 × 10²⁴
D)9.9 × 10 ^{− 23}

Question 26

Which of the following substances is an example of a weak electrolyte?

A)NaCl
B)K ₂ CrO ₄
C)KNO₃
D)CH₃COOH

Question 27

Which of the following equations best illustrates the net ionic equation for the reaction of radium chloride with potassium sulfate?

A)RaCl ₂ (aq)+ K ₂ SO ₄ (aq)→ RaSO ₄ (s)+ 2KCl(aq)
B)Ra ²⁺ (aq)+ 2Cl ^{1 −} (aq)+ 2K ¹⁺ (aq)+ SO ₄ ^{2 −} (aq)→ RaSO ₄ (s)+ 2Cl ^{1 −} (aq)+ 2K ¹⁺ (aq)
C)Ra ²⁺ (aq)+ SO ₄ ^{2 −} (aq)→ RaSO ₄ (s)
D)Ra ²⁺ (aq)+ 2Cl ^{1 −} (aq)+ 2K ¹⁺ (aq)+ SO ₄ ^{2 −} (aq)→ RaSO ₄ (s) + 2KCl(aq)

Question 28

Which of the following statements is true of the reaction between Ba(NO ₃ ) ₂ and Na ₂ SO ₄ ?

A)Two moles of Ba(NO ₃ ) ₂ and four moles of Na ₂ SO ₄ react without excess remaining.
B)Two moles of Ba(NO ₃ ) ₂ react with excess Na ₂ SO ₄ to form two moles of BaSO ₄ .
C)These two compounds react to form solid NaNO ₃ , Ba ²⁺ , and SO ₄ ^{2 −} .
D)Sulfate is a spectator ion.

Question 29

In the given equation, which of the following species is classified as a spectator ion? Pb(ClO ₃ ) ₂ (aq)+ KBr(aq) → PbBr ₂ (s)+ KClO ₃ (aq)

A)Pb ²⁺ (aq)
B)ClO ₄ ^{1 −} (aq)
C)K ¹⁺ (aq)
D)Br ^{1 −} (aq)

Question 30

Which of the following substances is an example of a strong electrolyte?

A)Sucrose
B)Table salt
C)Ammonia
D)Acetic acid

Question 31

If 225.6 g of silver chloride is produced in a precipitation reaction, how many moles of the salt are formed?

A)1.574 × 10⁰
B)4.403 × 10¹
C)1.039 × 10¹
D)9.471 × 10 ^{− 1}

Question 32

Identify a strong electrolyte.

A)C₆H₁₂O₆
B)KNO₃
C)Ag₂SO₄
D)CH ₃ COOH

Question 33

How many oxygen atoms are present in six molecules of Ce(NO₂)₃?

A)6
B)18
C)36
D)54

Question 34

Which of the following illustrates the balanced reaction of iron and oxygen to form iron (II)oxide?

A)Fe(s)+ O(g)→ FeO(s)
B)Fe ₂ (s) + O(g)→ Fe ₂ O(s)
C)2Fe(s)+ O ₂ (g)→ 2FeO(s)
D)4Fe(s)+ 3O ₂ (g)→ 2Fe ₂ O ₃ (s)

Question 35

How many atoms are present in 5.99 × 10 ^{− 14} moles of glucose (C₆H₁₂O₆)?

A)2.42 × 10³⁸
B)8.66 × 10¹¹
C)1.84 × 10²¹
D)3.61 × 10¹⁰

Question 36

87.2 g of IrCl₃contains _____ moles of the compound.

A)7.65
B)3.41
C)0.0819
D)0.292

Question 37

How many oxygen atoms are present in five molecules of CuSO ₄ ∙ 5H ₂ O?

A)45
B)50
C)25
D)20

Question 38

Which of the following statements is true of the reaction between Fe and CuCl ₂ ?

A)One mole of Fe and two moles of CuCl ₂ react without excess remaining.
B)Two moles of Fe react with excess CuCl ₂ to plate one mole of Cu.
C)These two substances react to form solid FeCl ₃ and Cu ²⁺ .
D)Chloride is a spectator ion.

Question 39

Which of the following illustrates the balanced reaction between magnesium and oxygen to form magnesium oxide?

A)Mg(s)+ O(g)→ MgO(s)
B)2Mg(s)+ O₂(g)→ 2MgO(s)
C)Mn(s)+ O(g)→ MnO(s)
D)2Mn(s)+ O₂(g) → 2MnO(s)

Question 40

How many aluminum atoms are present in four molecules of AlCl ₃ ?

A)1
B)3
C)4
D)12

Question 41

Elemental analysis measures the _____ of each element in a compound.

A)mass percentage
B)number of atoms
C)reactivity
D)affinity

Question 42

An unknown hydrocarbon is subjected to elemental analysis. The results of this test show that the compound is 83.24% carbon and 16.76% hydrogen With a molar mass of 72 g\mole, the molecular formula of this compound is _____.

A)C₄H₁₀
B)C₅H₁₀
C)C₅H₁₂
D)C₆H₁₄

Question 43

A 6.55 × 10 ^{− 3}M solution of Cd(NO₃)₂can be made by dissolving _____ g of the salt in sufficient water to make 500 mL of the solution.

A)0.991
B)1.549
C)0.585
D)0.774

Question 44

The process of removing carbon from the atmosphere is called _____.

A)combustion
B)carbon sequestration
C)carbon dilution
D)atmospheric fixation

Question 45

118.63 g of SrCl₂∙ 6H₂O contains _____ molecules of strontium chloride.

A)2.680 × 10²³
B)1.346 × 10²⁴
C)5.540 × 10²³
D)6.224 × 10 ^{− 24}

Question 46

Which of the following statements is true of chemical reactions?

A)They always release heat.
B)They always absorb heat.
C)They create atoms of the elements taking part in the reaction.
D)They rearrange the elements into different molecules in the reaction.

Question 47

If 92.8 g of sodium nitrite is dissolved in sufficient water to prepare 2.3 L of solution, the resulting solution has a molarity of _____.

A)1.34 M
B)0.890 M
C)0.58 M
D)1.92 M

Question 48

What is the volume of a 0.5 M H₂SO₄solution obtained by diluting 100 mL of a 2.00 M H₂SO₄solution?

A)200 mL
B)300 mL
C)400 mL
D)500 mL

Question 49

Sucrose solution conducts electricity.

Question 50

What volume of a 1.00 M HCl solution must be diluted to obtain 200 mL of a 0.250 M HCl solution?

A)30.0 mL
B)50.0 mL
C)60.0 mL
D)75.0 mL