Question 1

What is the oxidation number change for the iron atom in the following reaction? 2 Fe₂O₃(s)+ 3 C(s)→ 4 Fe(s)+ 3 CO₂(g) A)-6 B)-3 C)+3 D)+6

Accepted Answer

The answer of What is the oxidation number change for...

Question 2

When 50.0 mL of a 1.00 M solution of Fe(NO₃)₃ are mixed with 50.0 mL of a 1.00 M solution of NaOH,a precipitate forms.How many moles of precipitate is formed? Fe(NO₃)₃(aq)+ 3 NaOH(aq)→ Fe(OH)₃(s)+ 3 NaNO₃(aq) A)0.33 moles B)1.00 mole C)0.05 moles D)0.017 moles

Accepted Answer

The reaction shows that 1 mole of Fe(NO₃)₃ reacts with 3 moles of NaOH to form 1 mole of Fe(OH)₃. Since both solutions are 50.0 mL of 1.00 M, they contain 0.05 moles each. Fe(NO₃)₃ is the limiting reactant, so 0.05 moles of Fe(OH)₃ precipitate is formed.

Question 3

Disproportionation is a reaction in which a substance is both oxidized and reduced in the reaction.Which is a disproportionation reaction? A)ClO₃^-(aq)+ 3 Cu(s)+ 6 H⁺(aq)→ Cl^-(aq)+ 3 Cu²⁺(aq)+ 3 H₂O(l) B)ClO^-(aq)+ Pb(OH)₄^-(aq)→ Cl^-(aq)+ PbO₂(s)+ H₂O(l)+ 2 OH^-(aq) C)6 Cl^-(aq)+ Cr₂O₇^2-(aq)+ 14 H⁺(aq)→ 3 Cl₂(g)+ 2 Cr³⁺(aq)+ 7 H₂O(l) D)Cl₂(g)+ 2 OH^-(aq)→ Cl^-(aq)+ ClO^-(aq)+ H₂O(l)

Accepted Answer

In option D, chlorine is both oxidized to ClO^- and reduced to Cl^-, which fits the definition of a disproportionation reaction.

Question 4

In the following reaction,Cl₂ is 2 Rb(s)+ Cl₂(g)→ 2 RbCl(s) A)the reducing agent. B)the oxidizing agent. C)oxidized. D)the electron donor.

Accepted Answer

Cl₂ is the oxidizing agent because it accepts electrons from Rb.

Question 5

When 50.0 mL of a 1.00M solution of Fe(NO₃)₃ are mixed with 50.0mL of a 1.00 M solution of NaOH,a precipitate forms.What ions remain after the reaction is complete? Fe(NO₃)₃(aq)+ 3 NaOH(aq)→ Fe(OH)₃(s)+ 3 NaNO₃(aq) A)Fe³⁺ and OH^- B)Fe³⁺,Na⁺,and OH^- C)Fe³⁺,OH^-,Na⁺,and NO₃^- D)Na⁺ and NO₃^-

Accepted Answer

The answer of When 50.0 mL of a 1.00M solution...

Question 6

Which species functions as the oxidizing agent in the following reduction-oxidation reaction? 5 Fe²⁺(aq)+ MnO₄^-(aq)+ 8 H⁺(aq)→ Mn²⁺(aq)+ 5 Fe³⁺(aq)+ 4 H₂O(l) A)Fe²⁺(aq) B)H⁺(aq) C)Mn²⁺(aq) D)MnO₄^-(aq)

Accepted Answer

MnO₄^-(aq) is the species that undergoes reduction, therefore it functions as the oxidizing agent.

Question 7

The oxidation state of chlorine in ClO₄^- is A)0 B)+5 C)-5 D)+7

Accepted Answer

The given formula represents perchlorate ion (ClO4^-). In this ion, chlorine (Cl) has an oxidation state of +7. This is calculated by assigning oxygen (O) an oxidation state of -2 (since there are four oxygens, that's -8 total) and solving for Cl in the equation Cl + 4(-2) = -1 (the charge on the ion).

Question 8

Using the following sequence of reactions,determine the order of reducing agents (strongest to weakest). A + B⁺ → A⁺ + B A + C⁺ → A⁺ + C B + C⁺ → no reaction A)A > B > C B)A > C > B C)B > C > A D)C⁺ > B⁺ > A⁺

Accepted Answer

The order of reducing agents can be determined by looking at the products formed in the reactions. A reducing agent is a substance that donates electrons, causing a reduction in another substance. In the given reactions, A and B are both reducing agents because they both cause a reduction in the reactants they are reacting with. C, however, does not cause a reduction in the reactant it is reacting with, therefore it is not a reducing agent. Comparing reactions 1 and 2, we see that A is a stronger reducing agent than C because it is able to reduce B⁺ and C⁺ to the same products. Therefore, the order of reducing agents from strongest to weakest is A > C. Reaction 3 tells us that B cannot reduce C⁺, so it is a weaker reducing agent than both A and C. Therefore, the complete order of reducing agents from strongest to weakest is A > C > B.

Question 9

What is the oxidation number of the sulfur atom in S₈? A)-2 B)0 C)+6 D)+8

Accepted Answer

The oxidation number of an element in its elemental form is always 0.

Question 10

How many milliliters of 0.550 M hydriodic acid are needed to react with 25.00 mL of 0.330 M CsOH? HI(aq)+ CsOH(aq)→ CsI(aq)+ H₂O(l) A)0.133 mL B)0.0667 mL C)15.0 mL D)41.7 mL

Accepted Answer

To find the volume of HI needed, use the formula M1V1 = M2V2. Here, M1 = 0.550 M, V1 = ?, M2 = 0.330 M, V2 = 25.00 mL. Solving for V1 gives V1 = (0.330 M * 25.00 mL) / 0.550 M = 15.0 mL.

Question 11

Using the following sequence of reactions,determine the order of oxidizing agents (strongest to weakest). Q + U⁺ → Q⁺ + U U + W⁺ → U⁺ + W Q + W⁺ → Q⁺ + W A)Q > U > W B)W > U > Q C)Q⁺ > U⁺ > W⁺ D)W⁺ > U⁺ > Q⁺

Accepted Answer

The order of oxidizing agents can be determined by looking at the reactant on the left-hand side of each equation. The oxidizing agent will be the reactant that undergoes reduction. 
In the first equation, Q is reduced to QS1U1P1. In the second equation, U is reduced to US1U1P1. In the third equation, W is reduced to WS1U1P1. 
Since WS1U1P1 is the strongest oxidizing agent (it is reduced in both the second and third equation), followed by US1U1P1 (reduced only in the second equation), and then QS1U1P1 (reduced only in the first equation), the correct answer is D.

Question 12

Using the following portion of the activity series for oxidation half-reactions,determine which combination of reactants will result in a reaction. Li(s)→ Al³⁺(aq)+ e^- Cr(s)→ Al³⁺(aq)+ 3e^- A)Li(s)with Al(s) B)Li(s)with Al³⁺(aq) C)Li⁺(aq)with Al³⁺(aq) D)Li⁺(aq)with Al(s)

Accepted Answer

In the activity series, a metal can displace another metal from its compound in solution if it is higher in the series. Lithium (Li) is higher than aluminum (Al) in the activity series, meaning Li can displace Al from its compounds in solution, making choice B correct.

Question 13

In the reaction 2 H₂O₂(l)→ 2 H₂O(l)+ O₂(g)oxygen is A)both oxidized and reduced. B)neither oxidized nor reduced. C)only oxidized. D)only reduced.

Accepted Answer

In the given reaction, oxygen goes from an oxidation state of 0 in the reactant to -2 in the product. Thus, it is reduced. On the other hand, sulfur goes from an oxidation state of +6 in the reactant to +4 in the product. Thus, it is oxidized. Therefore, both the oxidizing and reducing agents are present in the reaction, making it a redox reaction. Thus, the correct answer is A. Neither B, C, nor D are correct because they do not account for both oxidation and reduction occurring in the reaction.

Question 14

Which species functions as the reducing agent in the following reduction-oxidation reaction? 2 P(s)+ 3 Br₂(l)→ 2 PBr₃(l) A)Br^-(aq) B)Br₂(l) C)P(s) D)P³⁺(aq)

Accepted Answer

In the given reaction, P(s) is oxidized by Br to form PBr3. This implies that Br is the oxidizing agent and P(s) is the reducing agent.

Question 15

Using the following portion of the activity series for oxidation half reactions Ca(s)→ Ca²⁺(aq)+ 2e^- Mg(s)→ Mg²⁺(aq)+ 2e^- Zn(s)→ Zn²⁺(aq)+ 2e^- Cu(s)→ Cu²⁺(aq)+ 2e^- Determine which reaction will not occur. A)Ca(s)with Cu²⁺(aq) B)Ca(s)with Zn²⁺(aq) C)Zn(s)with Cu²⁺(aq) D)Zn(s)with Mg²⁺(aq)

Accepted Answer

Zinc (Zn) is less reactive than magnesium (Mg) according to the activity series, so Zn cannot displace Mg from Mg²⁺(aq).

Question 16

Using the following portion of the activity series for oxidation half reactions K(s)→ K⁺(aq)+ e^- Al(s)→ Al³⁺(aq)+ 3e^- Fe(s)→ Fe²⁺(aq)+ 2e^- Sn(s)→ Sn²⁺(aq)+ 2e^- Determine which reaction will occur. A)Al³⁺(aq)with Fe(s) B)Al(s)with Sn(s) C)K⁺(aq)with Fe²⁺(aq) D)K(s)with Sn²⁺(aq)

Accepted Answer

The answer of Using the following portion of the activity...

Question 17

What is the oxidation number change for the manganese atom in the following unbalanced reduction half reaction? MnO₄^-(aq)+ H⁺(aq)→ Mn²⁺(aq)+ H₂O(l) A)-7 B)-5 C)+5 D)+7

Accepted Answer

The answer of What is the oxidation number change for...

Question 18

What is the oxidation number of the sulfur atom in SO₂? A)-2 B)+2 C)-4 D)+4

Accepted Answer

In SO₂, oxygen has an oxidation number of -2. Since there are two oxygen atoms, their total contribution is -4. To balance this and make the compound neutral, sulfur must have an oxidation number of +4.

Question 19

What is the oxidation number of the chromium atom in K₂Cr₂O₄? A)-2 B)+3 C)+6 D)+7

Accepted Answer

The answer of What is the oxidation number of the...

Question 20

Which species functions as the reducing agent in the following reduction-oxidation reaction? ZnO(s)+ C(s)→ Zn(s)+ CO(g)
A)C(s)
B)CO(g)
C)Zn(s)
D)ZnO(s)

Accepted Answer

In a redox reaction, the reducing agent is the species that loses electrons and gets oxidized. In this reaction, carbon (C) is oxidized to CO, which means it loses electrons and functions as the reducing agent. The zinc oxide (ZnO) is reduced to zinc (Zn) by gaining electrons, and so it functions as the oxidizing agent. The products of the reaction are zinc (Zn) and carbon monoxide (CO).

Quiz 4: Reactions in Aqueous Solutions

What is the oxidation number change for the iron atom in the following reaction? 2 Fe₂O₃(s) + 3 C(s) → 4 Fe(s) + 3 CO₂(g)

When 50.0 mL of a 1.00 M solution of Fe(NO₃) ₃ are mixed with 50.0 mL of a 1.00 M solution of NaOH,a precipitate forms.How many moles of precipitate is formed? Fe(NO₃) ₃(aq) + 3 NaOH(aq) → Fe(OH) ₃(s) + 3 NaNO₃(aq)

Disproportionation is a reaction in which a substance is both oxidized and reduced in the reaction.Which is a disproportionation reaction?

In the following reaction,Cl₂ is 2 Rb(s) + Cl₂(g) → 2 RbCl(s)

When 50.0 mL of a 1.00M solution of Fe(NO₃) ₃ are mixed with 50.0mL of a 1.00 M solution of NaOH,a precipitate forms.What ions remain after the reaction is complete? Fe(NO₃) ₃(aq) + 3 NaOH(aq) → Fe(OH) ₃(s) + 3 NaNO₃(aq)

Which species functions as the oxidizing agent in the following reduction-oxidation reaction? 5 Fe²⁺(aq) + MnO₄^-(aq) + 8 H⁺(aq) → Mn²⁺(aq) + 5 Fe³⁺(aq) + 4 H₂O(l)

The oxidation state of chlorine in ClO₄^- is

Using the following sequence of reactions,determine the order of reducing agents (strongest to weakest) . A + B⁺ → A⁺ + B A + C⁺ → A⁺ + C B + C⁺ → no reaction

What is the oxidation number of the sulfur atom in S₈?

How many milliliters of 0.550 M hydriodic acid are needed to react with 25.00 mL of 0.330 M CsOH? HI(aq) + CsOH(aq) → CsI(aq) + H₂O(l)

Using the following sequence of reactions,determine the order of oxidizing agents (strongest to weakest) . Q + U⁺ → Q⁺ + U U + W⁺ → U⁺ + W Q + W⁺ → Q⁺ + W

Using the following portion of the activity series for oxidation half-reactions,determine which combination of reactants will result in a reaction. Li(s) → Al³⁺(aq) + e^- Cr(s) → Al³⁺(aq) + 3e^-

In the reaction 2 H₂O₂(l) → 2 H₂O(l) + O₂(g) oxygen is

Which species functions as the reducing agent in the following reduction-oxidation reaction? 2 P(s) + 3 Br₂(l) → 2 PBr₃(l)

Using the following portion of the activity series for oxidation half reactions Ca(s) → Ca²⁺(aq) + 2e^- Mg(s) → Mg²⁺(aq) + 2e^- Zn(s) → Zn²⁺(aq) + 2e^- Cu(s) → Cu²⁺(aq) + 2e^- Determine which reaction will not occur.

Using the following portion of the activity series for oxidation half reactions K(s) → K⁺(aq) + e^- Al(s) → Al³⁺(aq) + 3e^- Fe(s) → Fe²⁺(aq) + 2e^- Sn(s) → Sn²⁺(aq) + 2e^- Determine which reaction will occur.

What is the oxidation number change for the manganese atom in the following unbalanced reduction half reaction? MnO₄^-(aq) + H⁺(aq) → Mn²⁺(aq) + H₂O(l)

What is the oxidation number of the sulfur atom in SO₂?

What is the oxidation number of the chromium atom in K₂Cr₂O₄?

Which species functions as the reducing agent in the following reduction-oxidation reaction? ZnO(s) + C(s) → Zn(s) + CO(g)

Quiz 4: Reactions in Aqueous Solutions

What is the oxidation number change for the iron atom in the following reaction? 2 Fe2O3(s) + 3 C(s) → 4 Fe(s) + 3 CO2(g)

When 50.0 mL of a 1.00 M solution of Fe(NO3) 3 are mixed with 50.0 mL of a 1.00 M solution of NaOH,a precipitate forms.How many moles of precipitate is formed? Fe(NO3) 3(aq) + 3 NaOH(aq) → Fe(OH) 3(s) + 3 NaNO3(aq)

Disproportionation is a reaction in which a substance is both oxidized and reduced in the reaction.Which is a disproportionation reaction?

In the following reaction,Cl2 is 2 Rb(s) + Cl2(g) → 2 RbCl(s)

When 50.0 mL of a 1.00M solution of Fe(NO3) 3 are mixed with 50.0mL of a 1.00 M solution of NaOH,a precipitate forms.What ions remain after the reaction is complete? Fe(NO3) 3(aq) + 3 NaOH(aq) → Fe(OH) 3(s) + 3 NaNO3(aq)

Which species functions as the oxidizing agent in the following reduction-oxidation reaction? 5 Fe2+(aq) + MnO4-(aq) + 8 H+(aq) → Mn2+(aq) + 5 Fe3+(aq) + 4 H2O(l)

The oxidation state of chlorine in ClO4- is

Using the following sequence of reactions,determine the order of reducing agents (strongest to weakest) . A + B+ → A+ + B A + C+ → A+ + C B + C+ → no reaction

What is the oxidation number of the sulfur atom in S8?

How many milliliters of 0.550 M hydriodic acid are needed to react with 25.00 mL of 0.330 M CsOH? HI(aq) + CsOH(aq) → CsI(aq) + H2O(l)

Using the following sequence of reactions,determine the order of oxidizing agents (strongest to weakest) . Q + U+ → Q+ + U U + W+ → U+ + W Q + W+ → Q+ + W

Using the following portion of the activity series for oxidation half-reactions,determine which combination of reactants will result in a reaction. Li(s) → Al3+(aq) + e- Cr(s) → Al3+(aq) + 3e-

In the reaction 2 H2O2(l) → 2 H2O(l) + O2(g) oxygen is

Which species functions as the reducing agent in the following reduction-oxidation reaction? 2 P(s) + 3 Br2(l) → 2 PBr3(l)

Using the following portion of the activity series for oxidation half reactions Ca(s) → Ca2+(aq) + 2e- Mg(s) → Mg2+(aq) + 2e- Zn(s) → Zn2+(aq) + 2e- Cu(s) → Cu2+(aq) + 2e- Determine which reaction will not occur.

Using the following portion of the activity series for oxidation half reactions K(s) → K+(aq) + e- Al(s) → Al3+(aq) + 3e- Fe(s) → Fe2+(aq) + 2e- Sn(s) → Sn2+(aq) + 2e- Determine which reaction will occur.

What is the oxidation number change for the manganese atom in the following unbalanced reduction half reaction? MnO4-(aq) + H+(aq) → Mn2+(aq) + H2O(l)

What is the oxidation number of the sulfur atom in SO2?

What is the oxidation number of the chromium atom in K2Cr2O4?