Deck 5: Introduction to Reactions in Aqueous Solutions

Question 1

Soluble ionic compounds form strong electrolytes.

Answer 1

True

Question 2

To precipitate Cd2+ from solution one could add:

A) H2S(aq)
B) HCl(aq)
C) HNO3(aq)
D) KI(aq)
E) NaCl(aq)

Answer 2

H2S(aq)

Question 3

What concentration of Fe2(SO4)3(aq) is required for the solution to have [Fe3+(aq)] = 0.32 M?

A) 0.16 M
B) 0.32 M
C) 0.64 M
D) 0.080 M
E) 0.12 M

Answer 3

0.16 M

Question 4

For redox reactions to be balanced, electrons should be present on the reactant side.

Question 5

Which statement below best describes net ionic equations?

A) A net ionic equation lists all ions in the solution.
B) A net ionic equation is obtained when the ions forming the precipitate are removed from the molecular equation.
C) A net ionic equation is a balanced chemical equation that includes only ions that actually participate in a reaction.
D) A net ionic equation is a balanced chemical equation that includes all the ions present in a reaction mixture.
E) A net ionic reaction is a balanced chemical equation that clearly shows spectator ions in a reaction.

Question 6

The hydrated proton attracts only one water molecule.

Question 7

A reducing agent causes itself to be reduced.

Question 8

What is the concentration of Br-(aq) in a solution prepared by mixing 75.0 mL of 0.62 M iron(III) bromide with 75.0 mL of water? Assume volumes are additive.

A) 0.93 M
B) 0.31 M
C) 1.9 M
D) 0.62 M
E) 1.23 M

Question 9

An insoluble compound will dissolve to an appreciable amount in water.

Question 10

An oxidizing agent is reduced during a redox reaction.

Question 11

Choose the INCORRECT statement.

A) A non-electrolyte is not ionized and does not conduct an electric current.
B) A strong electrolyte is completely ionized in water solution.
C) A strong electrolyte in solution is a good electrical conductor.
D) A weak electrolyte in solution is a good electrical conductor.
E) A weak electrolyte is partially ionized in a water solution.

Question 12

A titration is a method of adding small amounts of one reactant until the reaction is complete.

Question 13

A solid forming from a mixture of solutions is called a precipitate.

Question 14

In 0.20 M NH₃(aq), the concentration of NH₄+(aq) and OH-(aq) are approximately 0.20 M.

Question 15

Most water-soluble compounds of Group 1A or 2A elements are:

A) strong electrolytes
B) strong acids
C) weak electrolytes
D) weak acids
E) nonelectrolytes

Question 16

Weak acids almost completely dissociate.

Question 17

Oxidation never occurs alone.

Question 18

Which of the following solutions has the lowest concentration of sulfate ion?

A) 0.1 M Al2(SO4)3
B) 0.2 M MgSO4
C) 0.3 M Li2SO4
D) 0.4 M K2SO4
E) 0.5 M CuSO4

Question 19

Which of the following solutions has the highest fluoride concentration?

A) 0.05 M CaF2
B) 2.1 mg NaF/L
C) a solution having 1.5 mg F-/L
D) a solution having 0.06 M F-
E) 0.05 M NaF

Question 20

Which of the following is probably the poorest electrical conductor?

A) 0.5 M K2SO4
B) 0.5 M CaCl2
C) 0.5 M HF
D) 0.5 M CH3OH
E) 0.5 M NH3

Question 21

Which of the following compounds is quite insoluble in water, but would liberate a gas when treated with aqueous acetic acid?

A) K2CO3
B) K2SO4
C) CaCO3
D) CaSO4
E) AgCl

Question 22

The substance BaCl2 is a:

A) salt
B) weak acid
C) strong base
D) weak base
E) strong acid

Question 23

Which of the following combinations is correct?

A) NaOH/weak base
B) H3PO4/strong acid
C) HNO3/weak acid
D) NH3/strong base
E) HClO4/strong acid

Question 24

The substance HNO2 is a:

A) strong base
B) strong acid
C) weak acid
D) weak base
E) salt

Question 25

Assuming that the proposed reactants are mixed in stoichiometric ratios, and at moderate concentrations, which of the following is least likely to represent an observable (e.g., gas evolution or precipitation) reaction?

A) Ca2+ + 2 Cl- + 2 K+ + CO32- → ?
B) 2 Na+ + CO32- + 2 HC2N3O2 → ?
C) H2S + Cu2+ + SO42- → ?
D) H2SO3 + Li+ + Cl- → ?
E) Pb2+ + 2 NO3- + 2 Na+ + 2 OH- → ?

Question 26

Which of the following would have the strongest tendency of producing OH- ions in an aqueous solution?

A) Fe(OH)2
B) Fe(OH)3
C) Ba(OH)2
D) NaOH
E) HOCl

Question 27

The substance NH3 is a:

A) weak acid
B) strong acid
C) salt
D) weak base
E) strong base

Question 28

Which of the following would have the strongest tendency for producing H+ ions in an aqueous solution?

A) NH3
B) HNO2
C) H2S
D) HNO3
E) CH3COOH

Question 29

The substance KOH is a:

A) weak acid
B) salt
C) weak base
D) strong base
E) strong acid

Question 30

To precipitate Ba2+ from solution, one could add:

A) HCl(aq)
B) (NH4)2CO3(aq) in HN3(aq)
C) H2S(aq) in NH3/NH4+(aq)
D) H2S(aq) in 0.3 M HCl(aq)
E) NaCl(aq)

Question 31

The substance CH3COOH in water is a:

A) strong electrolyte
B) weak electrolyte
C) nonelectrolyte
D) strong acid
E) strong base

Question 32

Which of the following represents a neutralization reaction?

A) 2 H2(g) + O2(g) → 2 H2O(l)
B) NH3(aq) + HCl(aq) → NH4Cl(aq)
C) 2 NaOH(aq) + CuCl2(aq) → 2 NaCl(aq) + Cu(OH)2(s)
D) HBr(aq) + AgNO3(aq) → HNO3(aq) + AgBr(s)
E) 2 H2O2(aq) → 2 H2O(l) + O2(g)

Question 33

The substance KClO4 in water solution is a:

A) strong electrolyte
B) nonelectrolyte
C) weak electrolyte
D) strong base
E) weak acid

Question 34

The substance NaOH in water solution is a:

A) nonelectrolyte
B) weak electrolyte
C) weak base
D) strong electrolyte
E) weak acid

Question 35

Choose the INCORRECT statement.

A) Most molecular compounds are either nonelectrolytes or weak electrolytes.
B) Most ionic compounds are strong electrolytes.
C) A precipitate is formed when certain anions and cations react to form an insoluble ionic solid.
D) Net ionic equations include only the actual participants of the reaction.
E) An acid produces hydride ions in solution.

Question 36

The substance C5H5OH in water solution is a:

A) weak electrolyte
B) strong acid
C) strong electrolyte
D) nonelectrolyte
E) strong base

Question 37

Choose the INCORRECT statement.

A) A base produces hydrogen ions in solution.
B) A strong acid is a strong electrolyte.
C) Weak acids are weak electrolytes.
D) In a neutralization reaction, an acid reacts with a base.
E) Acids contain ionizable hydrogens.

Question 38

Which of the following pairs of aqueous solutions will give a precipitate when mixed?

A) K3PO4 and CaCl2
B) LiClO4 and Ba(OH)2
C) AgNO3 and Ca(ClO4)2
D) NaCl and K(CH3COO)
E) Sr(NO3)2 and KI

Question 39

The substance HI is a:

A) strong acid
B) weak base
C) strong base
D) salt
E) weak acid

Question 40

Which of the following, in aqueous solution, is most likely to behave as a weak acid?

A) HCl
B) HCN
C) NaCl
D) NaCN
E) NH3

Question 41

Iron in the form FeCl2 can be determined by titration with potassium dichromate: 6FeCl2(aq) + K2Cr2O7(aq) + 14HCl(aq) → 6FeCl3(aq) + 2CrCl3(aq) + 2KCl(aq) + 7H2O(l)
An iron sample of mass 0.800 g required 18.80 mL of 0.0120 M K2Cr2O7(aq) to reach the end point. How many moles of FeCl2 were in the sample?

A) 1.43 × 10-2 mol
B) 1.35 × 10-3 mol
C) 3.75 × 10-5 mol
D) 2.26 × 10-4 mol
E) 1.13 × 10-4 mol

Question 42

A solution is 0.660 M in HNO3 and 1.02 M in Ca(NO3)2. What is the molarity of NO3- in the solution?

A) 2.70 M
B) 1.68 M
C) 1.02 M
D) 0.660 M
E) 0.360 M

Question 43

Write the net ionic equation for the reaction of barium chloride and sodium sulfate.

A) BaCl(aq) + NaSO4(aq) → BaSO4(s) + NaCl(aq)
B) BaCl(aq) + SO42- → BaSO4(s) + Ba2+
C) Ba2+ + SO42- → BaSO4(aq)
D) Ba2+ + SO42- → BaSO4(s)
E) no reaction

Question 44

Which of the following is most likely to be a strong oxidizing agent?

A) MnO
B) MnO2
C) KMnO4
D) Mn2O3
E) Mn3O4

Question 45

12.5 mL of 0.280 M HNO3 and 5.0 mL of 0.920 M KOH are mixed. Is the resulting solution acidic, basic, or neutral?

A) acidic
B) basic
C) neutral
D) HNO3 and KOH don't mix.

Question 46

In which of the following pairs is the oxidation number for the underlined element INCORRECT?

A) BrO4-/(+7)
B) CO32-/+4
C) FeO/+2
D) IO3-/+5
E) Mg(OH)2/+3

Question 47

In which of the following pairs is the oxidation number for the underlined element INCORRECT?

A) MnO2/(+4 )
B) SO32-/(+4)
C) ClO3-/(+7)
D) NO2-/(+3)
E) Cr2O3/(+3)

Question 48

A disproportionation reaction is one in which:

A) the equation is not balanced
B) the same substance is oxidized and reduced
C) more of one substance reacts than another
D) water must be added
E) both reactants are reduced

Question 49

Complete the equation and indicate if a precipitate forms. Li+ + Br- + Pb2+ + NO3- →

A) PbBr2(s) + LiNO3(s)
B) Pb2+ + 2 Br- + LiNO3(s)
C) Pb(NO3)2(s) + Li+ + 2 Br-
D) no reaction
E) PbBr2(s) + Li+ + NO3-

Question 50

Which of the following is most likely to act as a reducing agent?

A) H2S
B) SO2
C) SO3
D) H2SO4
E) H2S2O8

Question 51

Trace amounts of oxygen gas can be "scrubbed" from gases using the following reaction: 4Cr2+(aq) + O2(g) + 4H+(aq) → 4Cr3+(aq) + 2H2O(l)
Which of the following statements is true regarding this reaction?

A) Oxygen gas is reduced to water.
B) Cr2+(aq) is the oxidizing agent.
C) O2(g) is the reducing agent.
D) Electrons are transferred from O2 to Cr2+.

Question 52

Which of the following pairs react to give both a precipitation and a neutralization reaction?

A) Ca(OH)2(aq) and H2SO4(aq)
B) Mg(OH)2(aq) and H2SO4(aq)
C) Sr(OH)2(aq) and HNO3(aq)
D) Ba(OH)2(aq) and HNO3(aq)

Question 53

Select a statement that best describes the oxidation process.

A) In oxidation process all elements change oxidation state.
B) In oxidation process all elements experience an increase in oxidation state.
C) In oxidation process some elements change their oxidation state.
D) In oxidation process some elements experience oxidation state increase.
E) In oxidation process only oxygen increases its oxidation state.

Question 54

In which of the following pairs is the oxidation number for the underlined element INCORRECT?

A) MnO4-/(+7 )
B) SO42-/(+4)
C) NH4+/(-3)
D) NO3-/(+5)
E) Cr2O72-/(+6)

Question 55

Write the net ionic equation for the reaction of lead(II) nitrate and sodium iodide.

A) Pb(NO3)2(aq) + 2NaI(aq) → PbI2(s) + 2 NaNO3(aq)
B) Pb2+ + 2 NaI(aq) → PbI2(s) + 2 Na
C) Pb2+ + 2 I- → PbI2(s)
D) Pb2+ + 2 I- → Pb2+ + 2 I-
E) no reaction

Question 56

In which of the following pairs is the oxidation number for the underlined element INCORRECT?

A) ClO4-/(+7)
B) S2O32-/+2
C) Fe2O3/+3
D) HCO3-/+3
E) CO2/+4

Question 57

Which of the following reactions is an oxidation-reduction reaction?

A) NH3(g) + H2O(l) → NH4OH(aq)
B) HCl(aq) + NaH2PO4(aq) → H3PO4(aq) + NaCl(aq)
C) 2 H2O(l) → H3O+ (aq) + OH- (aq)
D) Mg(OH)2(s) → Mg2+ (aq) + 2 OH- (aq)
E) CO(g) + H2O(g) → CO2(g) + H2(g)

Question 58

Which of the following represents a disproportionation reaction?

A) Br2 + H2O → HOBr + Br- + H+
B) S + SO2 + H2O → S2O32- + 2 H+
C) HOCl + OH- → H2O + OCl-
D) 3 S2- + 2 CrO42- + 8 H2O → 3 S + 2 Cr(OH)3 + 10 OH-
E) HF → H+ + F-

Question 59

Complete the equation and indicate if a precipitate forms. Ag+ + Br- + NO3- + K+ →

A) AgBr(s) + K+ + NO3-
B) AgNO3(s) + K+ + Br-
C) AgBr(s) + KNO3(s)
D) KNO3(s) + Ag+ + Br-
E) no reaction

Question 60

Which of the following reactions is an oxidation-reduction reaction?

A) NH4HS(s) → NH3(g) + H2S(g)
B) 2 NaHCO3(s) → Na2CO3(s) + H2O(g) + CO2(g)
C) N2O4(g) → 2 NO2(g)
D) 2 SO2(g) + O2(g) → 2 SO3(g)
E) 2 CH3COOH(aq) + Ba(OH)2(aq) → Ba(CH3COO)2(aq) + 2 H2O(l)

Question 61

What is the proper coefficient for water when the following equation is completed and balanced for the reaction in basic solution? C2O42- (aq) + MnO4- (aq) → CO32- (aq) + MnO2(s)

A) 4
B) 3
C) 2
D) 1
E) 0

Question 62

Write the net ionic equation for the reaction of ammonium chloride and potassium hydroxide.

A) NH4Cl(aq) + KOH(aq) → NH3(aq) + KCl(aq) + H2O
B) NH+4 + OH- → NH3(aq) + H2O
C) NH4Cl(aq) + OH- → NH3(aq) + Cl- + H2O
D) NH+4 + KOH → NH4OH(aq) + K+
E) no reaction

Question 63

Balance the following oxidation-reduction reaction in acid solution: MnO4- + H2C2O4 → Mn2+ + CO2 + H2O
The sum of the coefficients is ________.

A) 25
B) 47
C) 33
D) 18
E) 21

Question 64

Balance the following equation for an oxidation-reduction reaction occurring in an acidic solution: HCl + H2C2O4 + MnO2(s) → MnCl2 + CO2(g) + H2O
The sum of the coefficients is ________.

A) 7
B) 15
C) 45
D) 12
E) 9

Question 65

Balance the following equation for an oxidation-reduction reaction occurring in an acidic solution: CuS(s) + HNO3 → Cu(NO3)2 + H2O + NO(g) + S(s)
The sum of the coefficients is ________.

A) 23
B) 18
C) 35
D) 33
E) 45

Question 66

Complete the equation and indicate if a precipitate forms. Na+ + Cl- + NO3- + K+ →

A) NaCl(s) + NO3- + K+
B) NaNO3(s) + K+ + Cl-
C) KCl(s) + Na+ + NO3-
D) KNO3(s) + Na+ + Cl-
E) no reaction

Question 67

Complete the equation and indicate if a precipitate forms. Na+ + OH- + Mg2+ + Cl- →

A) NaCl(s) + Mg2+ + 2 OH-
B) Mg(OH)2(s) + Na+ + Cl-
C) MgCl2(s) + Na+ + OH-
D) MgCl2(s) + Na(OH)(s)
E) no reaction

Question 68

Balance the following equation for an oxidation-reduction reaction occurring in an acidic solution: ClO4- + SO32- → SO42- + Cl-
The sum of the coefficients is ________.

A) 8
B) 12
C) 10
D) 4
E) 6

Question 69

Balance the following equation in basic solution: Cr3+ + O22- → CrO42-
The sum of the coefficients is ________.

A) 13
B) 53
C) 27
D) 18
E) 38

Question 70

Write the net ionic equation for the reaction of ammonium chloride and iron(III) hydroxide.

A) 3 NH4Cl(aq) + Fe(OH)3(s) → 3 NH3(aq) + 3 H2O + FeCl3
B) 3 NH4+ + 3 OH- → 3 NH3(aq) + 3 H2O
C) 3 NH4Cl(aq) + 3 OH- → 3 NH3(aq) + 3 H2O + 3 Cl-
D) 3 NH4+ + Fe(OH)3(s) → 3 NH3(aq) + 3 H2O + Fe3+
E) no reaction

Question 71

Balance the following equation in basic solution: Br2 + Mn2+ → MnO2 + Br-
The sum of the coefficients is ________.

A) 8
B) 15
C) 12
D) 17
E) 11

Question 72

In a solution that is 0.50 M CH3COOH(aq) (acetic acid), the species with a concentration of approximately 0.50 M is ________.

A) HC2H3O2
B) C2H3O2-
C) H+
D) H+ and C2H3O2-

Question 73

Write the net ionic equation for the reaction of magnesium carbonate and nitric acid.

A) MgCO3(s) + 2 H+ → Mg2+ + H2O + CO2(g)
B) MgCO3(s) + 2 HNO3(aq) → Mg(NO3)2 + H2O + CO2(g)
C) MgCO3(s) + 2 HNO3(aq) → Mg(NO3)2(aq) + H2CO3(aq)
D) Mg2+ + CO32- + 2 H+ → Mg2+ + H2O + CO2(g)
E) no reaction

Question 74

When the following equation is completed and balanced for the reaction in acidic solution, what is the proper coefficient for H+? Zn(s) + Cr2O72- (aq) → Zn2+ (aq) + Cr2+ (aq)

A) 22
B) 18
C) 14
D) 11
E) 7

Question 75

Balance the following equation for an oxidation-reduction reaction occurring in an acidic solution: IO3- + N2H4 → I- + N2 + H2O
The sum of the coefficients is ________.

A) 8
B) 25
C) 18
D) 16
E) 32

Question 76

How many electrons are transferred when the perchlorate ion is converted to chloride?

A) 8
B) 7
C) 9
D) 6
E) 5

Question 77

Balance the following oxidation-reduction reaction in acid solution: SO32- + MnO4- → SO42- + Mn2+ + H2O
The sum of the coefficients is ________.

A) 23
B) 30
C) 13
D) 45
E) 28

Question 78

Balance the following equation for an oxidation-reduction reaction occurring in an acidic solution: HNO3 + I2 → HIO3 + NO2 + H2O
The sum of the coefficients is ________.

A) 26
B) 27
C) 28
D) 33
E) 45

Question 79

For the reaction between aqueous potassium hydroxide and aqueous nitric acid, the so-called "spectator" ions are ________.

A) K+ and OH-
B) H+ and NO3-
C) K+ and NO3-
D) H+ and OH-

Question 80

Balance the following oxidation-reduction reaction in acid solution: Fe(s) → Fe2+ + H2(g)
The sum of the coefficients is ________.

A) 2
B) 5
C) 8
D) 7
E) 9