Question 1

Which of the following equations is not balanced?

Accepted Answer

A) C7H16 + O2 → 7 CO2 + 8 H2O 
B) K2CrO4 + Pb(NO3)2 → 2 KNO3 + PbCrO4 
C) 4 Fe3O4 + O2 → 6 Fe2O3 
D) 3 AgNO3 + (NH4)3PO4 → Ag3PO4 + 3 NH4NO3 
E) 2 Al2O3 → 4 Al + 3 O2

Question 2

All of the statements regarding redox reactions are true except

Accepted Answer

A) a reducing agent causes another substance to be reduced. 
B) halogens usually behave as oxidizing agents because they readily gain electrons. 
C) metal ions are produced when pure metals are oxidized. 
D) when a substance is oxidized its charge (or oxidation number)decreases. 
E) alkali metals often behave as reducing agents because they readily lose electrons.

Question 3

When the reaction shown is correctly balanced,the coefficients are:
KClO3 → KCl + O2

Accepted Answer

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

Question 4

Which reaction is not an example of a redox reaction?

Accepted Answer

A) 2 Hg (l)+ O2 (g)→ 2 HgO (s) 
B) 2 (NH4)3PO4 (aq)+ 3 Ba(NO3)2 (aq)→ Ba3(PO4)2 (s)+ 6 NH4NO3 (aq) 
C) CH4 (g)+ 2 O2 (g)→ CO2 (g)+ 2 H2O (g) 
D) 6 HCl (aq)+ 2 Al (s)→ 2 AlCl3 (aq)+ 3 H2 (g) 
E) 2 Al2O3 (s)→ 4 Al (s)+ 3 O2 (g)

Question 5

When the reaction shown is correctly balanced,the coefficients are:
____ HBr + ____ Ca(OH)2 → ____ CaBr2 + ____ H2O

Accepted Answer

A) 2,1,1,1 
B) 1,1,1,2 
C) 2,1,1,2 
D) 2,2,1,1 
E) 2,1,2,2

Question 6

What are the spectator ions in the reaction between KOH and HNO3?

Accepted Answer

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

Question 7

The following reaction can be classified as what type(s)of reaction(s)?
2 Al(OH)3 (aq)+ 3 H2SO4 (aq)→ Al2(SO4)3 (s)+ 6 H2O (l)

Accepted Answer

A) precipitation 
B) acid-base neutralization 
C) redox reaction 
D) both A and B

Question 8

The scientific principle which is the basis for balancing chemical equations is

Accepted Answer

A) the Law of Conservation of Energy. 
B) the Law of Conservation of Mass. 
C) the Law of Conservation of Mass and Energy. 
D) the Law of Definite Proportions. 
E) Avogadro's Law.

Question 9

Match the following.
-HR (aq)+ XOH (aq)→ XR (aq)+ H2O (l)

Accepted Answer

A) redox 
B) acid-base 
C) precipitation

Question 10

Which of the following is always a spectator ion in a chemical reaction?

Accepted Answer

A) Na+ 
B) Cl- 
C) S2- 
D) Mg2+ 
E) All of these ions.

Question 11

Consider the reaction shown and identify the statement that is not true.
CaCO3 (s) 
CaO (s)+ CO2 (g)

Accepted Answer

A) This reaction is balanced as written. 
B) The reactant must be heated for this reaction to occur. 
C) The products are a solid and a gas. 
D) Water must be present for this reaction to occur. 
E) There are no solutions used in this reaction.

Question 12

2 AgNO3 (aq)+ K2SO4(aq)→ 2 KNO3 (aq)+ Ag2SO4s)
The net ionic reaction for the balanced equation shown above is

Accepted Answer

A) Ag+ +

→ AgNO3. 
B) 2 K+ +

→ K2SO4. 
C) K+ +

→ KNO3. 
D) 2 Ag+ +

→ Ag2SO4. 
E) H+ + OH- → H2O.

Question 13

Reduction is the process of

Accepted Answer

A) gaining hydrogen. 
B) losing oxygen. 
C) gaining electrons. 
D) forming an anion from a neutral atom. 
E) all of the above

Question 14

Match the following.
-LX (aq)+ MY (aq)→ LY (s)+ MX (aq)

Accepted Answer

A) redox 
B) acid-base 
C) precipitation

Question 15

In a chemical reaction

Accepted Answer

A) there are equal numbers of atoms on each side of the reaction arrow. 
B) there are equal numbers of molecules on each side of the reaction arrow. 
C) there are always the same number of products as there are reactants. 
D) the number of atoms present in a reaction can vary when the conditions change during the reaction. 
E) none of the above

Question 16

In the following reaction which species is being oxidized and which is being reduced?
2 Cr (s)+ 3 Cl2 (g)→ 2 CrCl3 (s)

Accepted Answer

A) oxidized: Cr; reduced: CrCl3 
B) oxidized:CrCl3; reduced: Cr 
C) oxidized: Cr; reduced: Cl2 
D) oxidized: Cl2; reduced: Cr

Question 17

When the reaction shown is correctly balanced,the coefficients are:
C6H14 (l)+ O2 (g)→ CO2 (g)+ H2O (g)

Accepted Answer

A) 1,6,6,7 
B) 2,19,12,14 
C) 1,3.5,6,7 
D) 1,9.5,6,7 
E) 2,16.5,12,7

Question 18

The formation of which one of the compounds below will act as the driving force for an acid-base reaction?

Accepted Answer

A) H2O 
B) MgCl2 
C) NaNO3 
D) KOH

Question 19

The combination of ions least likely to produce a precipitate is

Accepted Answer

A) Ba2+ and SO42-. 
B) Pb+ and Cl-. 
C) Ca2+ and PO43-. 
D) Fe3+ and OH-. 
E) Mg2+ and C2H3O2-.

Question 20

The combination of ions most likely to produce a precipitate is

Accepted Answer

A) Li+ and PO43-. 
B) Pb2+ and NO3-. 
C) NH4+ and SO42-. 
D) Fe3+ and OH-. 
E) Mg2+ and C2H3O2-.

Exam 5: Classification and Balancing of Chemical Reactions

Which of the following equations is not balanced?

All of the statements regarding redox reactions are true except

When the reaction shown is correctly balanced,the coefficients are: KClO₃ → KCl + O₂

Which reaction is not an example of a redox reaction?

When the reaction shown is correctly balanced,the coefficients are: HBr + Ca(OH) ₂ → CaBr₂ + H₂O

What are the spectator ions in the reaction between KOH and HNO₃?

The following reaction can be classified as what type(s) of reaction(s) ? 2 Al(OH) ₃ (aq) + 3 H₂SO₄ (aq) → Al₂(SO₄) ₃ (s) + 6 H₂O (l)

The scientific principle which is the basis for balancing chemical equations is

Match the following. -HR (aq) + XOH (aq) → XR (aq) + H₂O (l)

Which of the following is always a spectator ion in a chemical reaction?

Consider the reaction shown and identify the statement that is not true. CaCO₃ (s) CaO (s) + CO₂ (g)

2 AgNO₃ (aq) + K₂SO₄(aq) → 2 KNO₃ (aq) + Ag₂SO₄s) The net ionic reaction for the balanced equation shown above is

Reduction is the process of

Match the following. -LX (aq) + MY (aq) → LY (s) + MX (aq)

In a chemical reaction

In the following reaction which species is being oxidized and which is being reduced? 2 Cr (s) + 3 Cl₂ (g) → 2 CrCl₃ (s)

When the reaction shown is correctly balanced,the coefficients are: C₆H₁₄ (l) + O₂ (g) → CO₂ (g) + H₂O (g)

The formation of which one of the compounds below will act as the driving force for an acid-base reaction?

The combination of ions least likely to produce a precipitate is

The combination of ions most likely to produce a precipitate is

Exam 5: Classification and Balancing of Chemical Reactions

Which of the following equations is not balanced?

All of the statements regarding redox reactions are true except

When the reaction shown is correctly balanced,the coefficients are: KClO3 → KCl + O2

Which reaction is not an example of a redox reaction?

When the reaction shown is correctly balanced,the coefficients are: ____ HBr + ____ Ca(OH) 2 → ____ CaBr2 + ____ H2O

What are the spectator ions in the reaction between KOH and HNO3?

The following reaction can be classified as what type(s) of reaction(s) ? 2 Al(OH) 3 (aq) + 3 H2SO4 (aq) → Al2(SO4) 3 (s) + 6 H2O (l)

The scientific principle which is the basis for balancing chemical equations is

Match the following. -HR (aq) + XOH (aq) → XR (aq) + H2O (l)

Which of the following is always a spectator ion in a chemical reaction?

Consider the reaction shown and identify the statement that is not true. CaCO3 (s) CaO (s) + CO2 (g)

2 AgNO3 (aq) + K2SO4(aq) → 2 KNO3 (aq) + Ag2SO4s) The net ionic reaction for the balanced equation shown above is

Reduction is the process of

Match the following. -LX (aq) + MY (aq) → LY (s) + MX (aq)

In a chemical reaction

In the following reaction which species is being oxidized and which is being reduced? 2 Cr (s) + 3 Cl2 (g) → 2 CrCl3 (s)

When the reaction shown is correctly balanced,the coefficients are: C6H14 (l) + O2 (g) → CO2 (g) + H2O (g)

The formation of which one of the compounds below will act as the driving force for an acid-base reaction?

The combination of ions least likely to produce a precipitate is

The combination of ions most likely to produce a precipitate is

When the reaction shown is correctly balanced,the coefficients are: KClO₃ → KCl + O₂

When the reaction shown is correctly balanced,the coefficients are: HBr + Ca(OH) ₂ → CaBr₂ + H₂O

What are the spectator ions in the reaction between KOH and HNO₃?

The following reaction can be classified as what type(s) of reaction(s) ? 2 Al(OH) ₃ (aq) + 3 H₂SO₄ (aq) → Al₂(SO₄) ₃ (s) + 6 H₂O (l)

Match the following. -HR (aq) + XOH (aq) → XR (aq) + H₂O (l)

Consider the reaction shown and identify the statement that is not true. CaCO₃ (s) CaO (s) + CO₂ (g)

2 AgNO₃ (aq) + K₂SO₄(aq) → 2 KNO₃ (aq) + Ag₂SO₄s) The net ionic reaction for the balanced equation shown above is

In the following reaction which species is being oxidized and which is being reduced? 2 Cr (s) + 3 Cl₂ (g) → 2 CrCl₃ (s)

When the reaction shown is correctly balanced,the coefficients are: C₆H₁₄ (l) + O₂ (g) → CO₂ (g) + H₂O (g)