Question 1

In the properly balanced half-reaction (acid solution) for the system H₃AsO₃→H₂AsO₄^-, what else appears on the right side besides H₂AsO₄^-?

Accepted Answer

In an acidic solution, the half-reaction is balanced by adding H⁺ ions and electrons. The oxidation state of arsenic changes from +3 in H₃AsO₃ to +5 in H₂AsO₄^-, requiring 2 electrons. Balancing the hydrogen atoms requires adding 3 H⁺ ions.

Question 2

Start with the skeleton half-reaction CrO₂^-→CrO₄^{2 -}. When balanced in basic solution, what other species appear on the right side of the equation, in addition to CrO₄^{2 -}?

Accepted Answer

In order to balance the half-reaction in basic solution, we add OH- to both sides to neutralize the H+ ions, and then add water to balance the oxygen atoms. This gives us:

CrOS1U1B12S1U1B0S1U1P1 - S1S1P0 + 2 OH- -> CrOS1U1B14S1U1B0S1U1P12 - S1S1P0 + 3 H2OS1U1P1

We can see that we also have 3 electrons on both sides of the equation, but the question specifically asks for other species that appear on the right side besides the CrOS1U1B14S1U1B0S1U1P12 - S1S1P0 product. Looking at the right side of the equation, we can see that we have HS1U1B12S1U1B0O and electrons on the left side, but these have been consumed in the reaction to form H2OS1U1P1. Therefore, the only other species that appears on the right side is 2 HS1U1B12S1U1B0O, giving us answer choice A.

Question 3

After balancing the following reaction under acidic conditions , what is the coefficient for the species, BiO₃^{1 -}? Mn²⁺ (aq) + BiO₃^{1 -} (aq)→Bi³⁺ (aq) + MnO₄^{1 -} (aq) [Acidic conditions]

Accepted Answer

The answer of After balancing the following reaction under acidic...

Question 4

What is the oxidizing agent in the following reaction? H₂O + 2 MnO₄^{1 -} (aq) + I^- (aq)→2 MnO₂ (s) + IO₃^{1 -} (aq) + 2 OH^- (aq)

Accepted Answer

The oxidizing agent is the species that is reduced in the reaction. In this case, MnO₄^{1 -} is reduced to MnO₂, which means it is the oxidizing agent.

Question 5

In the redox reaction: 3 S^{2 -} + 2 MnO₄^- + 8 H₂O→3 S + 2 MnO₂ + 4 H₂O + 8 OH^- the S^{2 -} changes oxidation state to give the element S. Which statement below is true?

Accepted Answer

In the reaction, S^{2 -} loses electrons to form elemental sulfur (S), indicating it has been oxidized.

Question 6

The redox reaction (unbalanced), Cl₂→ClO₃^- + Cl^-, occurs in alkaline solution. The number of electrons transferred in the balanced equation is:

Accepted Answer

The answer of The redox reaction (unbalanced), Cl₂→ClO₃^-...

Question 7

After balancing the following reaction under basic conditions , how many mole equivalents of water are required and on which side of the reaction do they appear? CrO₄^{2 -} (aq) + Cu (s)→Cr(OH)₃ (s) + Cu(OH)₂ (s) [Basic conditions]

Accepted Answer

The answer of After balancing the following reaction under basic...

Question 8

After balancing the following reaction under acidic conditions , how many mole equivalents of water are required and on which side of the reaction do they appear? MnO₄^{1 -} (aq) + Cl^{1 -} (aq)→Mn²⁺ (aq) + Cl₂ (g) [Acidic conditions]

Accepted Answer

The answer of After balancing the following reaction under acidic...

Question 9

In the oxidation-reduction reaction shown below, the number of electrons transferred is: H₂O + 3 ClO^- (aq)→ClO₂^- (aq) + Cl₂ (aq) + 2 OH^- (aq)

Accepted Answer

In the given reaction, the chlorine atom undergoes a change in oxidation state from +5 in ClO to +7 in Cl, indicating that it has gained two electrons. Similarly, the sulfur atom undergoes a change in oxidation state from +6 in HS1U1B12S1U1B0O to +4 in ClOS1U1B12S1U1B0S1U1P1-, indicating that it has lost two electrons. Therefore, the number of electrons transferred is 2.

Question 10

After balancing the following reaction under acidic conditions , what is the coefficient for the species, Cl^{1 -}? MnO₄^{1 -} (aq) + Cl^{1 -} (aq)→Mn²⁺ (aq) + Cl₂ (g) [Acidic conditions]

Accepted Answer

The answer of After balancing the following reaction under acidic...

Question 11

After balancing the following reaction under basic conditions , what is the coefficient for the copper? CrO₄^{2 -} (aq) + Cu (s)→Cr(OH)₃ (s) + Cu(OH)₂ (s) [Basic conditions]

Accepted Answer

The balanced equation is:
CrO4^2- + 3HSO3^- + 3OH^- + Cu → Cr(OH)3 + Cu(OH)2 + 3SO4^2-
The coefficient for Cu is 1.

Question 12

Which equation listed below is correct after balancing the following unbalanced equation under basic conditions ? MnO₄^{1 -} (aq) + Br^{1 -} (aq)→MnO₂ (s) + BrO₃^{1 -} (aq) [Basic conditions]

Accepted Answer

The answer of Which equation listed below is correct after...

Question 13

After balancing the following reaction under basic conditions , how many electrons are transferred? MnO₄^{1 -} (aq) + Br^{1 -} (aq)→MnO₂ (s) + BrO₃^{1 -} (aq) [Basic conditions]

Accepted Answer

After balancing the reaction under basic conditions, the balanced equation is:

MnO4- + Br- → MnO2 + BrO3- (basic)

To balance the reaction, you need to add 6 electrons to the left-hand side (MnO4-) to balance the charges with the right-hand side (Br- and MnO2). Therefore, 6 electrons are transferred in this reaction.

Question 14

What species becomes oxidized and what species behaves as the reducing agent in the following oxidation-reduction reaction? 2 H₂ O ( ) + Al (s) + MnO₄ 1 - (aq) Al(OH) 4 1 - (aq) + MnO₂ (s)

Accepted Answer

In the given reaction, Al loses electrons and undergoes oxidation, therefore becoming the reducing agent. MnO4- gains electrons and undergoes reduction, therefore becoming the oxidizing agent.

Question 15

After balancing the following reaction under acidic conditions , how many electrons are transferred? Mn²⁺ (aq) + BiO₃^{1 -} (aq)→Bi³⁺ (aq) + MnO₄^{1 -} (aq) [Acidic conditions]

Accepted Answer

In the given reaction, Mn goes from a +2 oxidation state in Mn2+ to a +4 oxidation state in MnO2, losing 2 electrons in the process. Bi goes from a +3 oxidation state in BiO+ to a +5 oxidation state in Bi3+, losing 2 electrons. The sulfur atoms in the reactants and products do not change their oxidation states; thus, they do not contribute to the electron transfer in this reaction. Therefore, the total number of electrons transferred in the reaction is 2 (from Mn) + 2 (from Bi) = 4. However, without the specific details of the oxidation states of each element in the given compounds due to the formatting (^2,, etc.), a precise calculation cannot be made based on the provided information. The correct calculation involves identifying the changes in oxidation states of all elements involved and summing the total electrons transferred. Given the error in interpreting the specific details due to formatting, the correct answer based on standard redox reaction analysis principles cannot be accurately determined without the correct interpretation of the chemical species involved.

Question 16

In the following balanced redox reaction: 14 HCl + K₂Cr₂O₇ + 6 FeCl₂→2 CrCl₃ + 6 FeCl₃ + 2 KCl + 7 H₂O

Accepted Answer

FeCl₂ is a reducing agent because it donates electrons to K₂Cr₂O₇, reducing it to CrCl₃.

Question 17

Start with the skeleton half-reaction NO₃^-→NO₂. When balanced in acid solution, what other species appear on the left side of the equation, in addition to NO₃ ^-?

Accepted Answer

The answer of Start with the skeleton half-reaction NO₃^-...

Question 18

Given the skeleton half-reaction: Na₂C₂O₄→CO₂ + Na⁺ When the half-reaction is properly balanced we find that the half-reaction represents:

Accepted Answer

In the half-reaction, the oxidation state of carbon in Na2C2O4 increases from +3 to +4 in CO2, indicating a loss of electrons, which is characteristic of an oxidation process.

Question 19

Start with the skeleton half-reaction NO₂^-→NO₃^-. When balanced in basic solution, what other species appear on the right side of the equation, in addition to NO₃^-?

Accepted Answer

In order to balance the half-reaction in basic solution, we need to add OH- ions to the left side of the equation. This reacts with the H+ ions to form water. However, we also need to balance the charge by adding electrons. The electrons will appear on the left side of the equation, since they are being lost by the reactant. Therefore, the additional species that appear on the right side of the equation are the product of the reduction of HSO4- to SO42- and 2 e- (HSO4- + 2 e- -> SO42- + H2O) and the OH- ions that were added to balance the charges. The only choice that includes these species is C.

Question 20

In the oxidation-reduction equation (balanced): H₂O + 3 ClO^- (aq)→ClO₂^- (aq) + Cl₂ (aq) + 2 OH^- (aq)

Accepted Answer

ClO^- is reduced to Cl^- (gain of electrons), making it the oxidizing agent. Since it is reduced, it is also correct to say it is an oxidizing agent, fulfilling the criteria for choices A, C, and by definition, since it is oxidized or reduced, it is involved in a redox reaction, making D correct as well.

Quiz 18: Electrochemistry

In the properly balanced half-reaction (acid solution) for the system H₃AsO₃→H₂AsO₄^-, what else appears on the right side besides H₂AsO₄^-?

Start with the skeleton half-reaction CrO₂^-→CrO₄^{2 -}. When balanced in basic solution, what other species appear on the right side of the equation, in addition to CrO₄^{2 -}?

After balancing the following reaction under acidic conditions , what is the coefficient for the species, BiO₃^{1 -}? Mn²⁺ (aq) + BiO₃^{1 -} (aq) →Bi³⁺ (aq) + MnO₄^{1 -} (aq) [Acidic conditions]

What is the oxidizing agent in the following reaction? H₂O + 2 MnO₄^{1 -} (aq) + I^- (aq) →2 MnO₂ (s) + IO₃^{1 -} (aq) + 2 OH^- (aq)

In the redox reaction: 3 S^{2 -} + 2 MnO₄^- + 8 H₂O→3 S + 2 MnO₂ + 4 H₂O + 8 OH^- the S^{2 -} changes oxidation state to give the element S. Which statement below is true?

The redox reaction (unbalanced) , Cl₂→ClO₃^- + Cl^-, occurs in alkaline solution. The number of electrons transferred in the balanced equation is:

After balancing the following reaction under basic conditions , how many mole equivalents of water are required and on which side of the reaction do they appear? CrO₄^{2 -} (aq) + Cu (s) →Cr(OH) ₃ (s) + Cu(OH) ₂ (s) [Basic conditions]

After balancing the following reaction under acidic conditions , how many mole equivalents of water are required and on which side of the reaction do they appear? MnO₄^{1 -} (aq) + Cl^{1 -} (aq) →Mn²⁺ (aq) + Cl₂ (g) [Acidic conditions]

In the oxidation-reduction reaction shown below, the number of electrons transferred is: H₂O + 3 ClO^- (aq) →ClO₂^- (aq) + Cl₂ (aq) + 2 OH^- (aq)

After balancing the following reaction under acidic conditions , what is the coefficient for the species, Cl^{1 -}? MnO₄^{1 -} (aq) + Cl^{1 -} (aq) →Mn²⁺ (aq) + Cl₂ (g) [Acidic conditions]

After balancing the following reaction under basic conditions , what is the coefficient for the copper? CrO₄^{2 -} (aq) + Cu (s) →Cr(OH) ₃ (s) + Cu(OH) ₂ (s) [Basic conditions]

Which equation listed below is correct after balancing the following unbalanced equation under basic conditions ? MnO₄^{1 -} (aq) + Br^{1 -} (aq) →MnO₂ (s) + BrO₃^{1 -} (aq) [Basic conditions]

After balancing the following reaction under basic conditions , how many electrons are transferred? MnO₄^{1 -} (aq) + Br^{1 -} (aq) →MnO₂ (s) + BrO₃^{1 -} (aq) [Basic conditions]

What species becomes oxidized and what species behaves as the reducing agent in the following oxidation-reduction reaction? 2 H₂ O ( ) + Al (s) + MnO₄ 1 - (aq) Al(OH) 4 1 - (aq) + MnO₂ (s)

After balancing the following reaction under acidic conditions , how many electrons are transferred? Mn²⁺ (aq) + BiO₃^{1 -} (aq) →Bi³⁺ (aq) + MnO₄^{1 -} (aq) [Acidic conditions]

In the following balanced redox reaction: 14 HCl + K₂Cr₂O₇ + 6 FeCl₂→2 CrCl₃ + 6 FeCl₃ + 2 KCl + 7 H₂O

Start with the skeleton half-reaction NO₃^-→NO₂. When balanced in acid solution, what other species appear on the left side of the equation, in addition to NO₃ ^-?

Given the skeleton half-reaction: Na₂C₂O₄→CO₂ + Na⁺ When the half-reaction is properly balanced we find that the half-reaction represents:

Start with the skeleton half-reaction NO₂^-→NO₃^-. When balanced in basic solution, what other species appear on the right side of the equation, in addition to NO₃^-?

In the oxidation-reduction equation (balanced) : H₂O + 3 ClO^- (aq) →ClO₂^- (aq) + Cl₂ (aq) + 2 OH^- (aq)

Quiz 18: Electrochemistry

In the properly balanced half-reaction (acid solution) for the system H3AsO3→H2AsO4 - , what else appears on the right side besides H2AsO4 - ?

Start with the skeleton half-reaction CrO2 - →CrO42 - . When balanced in basic solution, what other species appear on the right side of the equation, in addition to CrO42 - ?

After balancing the following reaction under acidic conditions , what is the coefficient for the species, BiO31 - ? Mn2+ (aq) + BiO31 - (aq) →Bi3+ (aq) + MnO41 - (aq) [Acidic conditions]

What is the oxidizing agent in the following reaction? H2O + 2 MnO41 - (aq) + I - (aq) →2 MnO2 (s) + IO31 - (aq) + 2 OH - (aq)

In the redox reaction: 3 S2 - + 2 MnO4 - + 8 H2O→3 S + 2 MnO2 + 4 H2O + 8 OH - the S2 - changes oxidation state to give the element S. Which statement below is true?

The redox reaction (unbalanced) , Cl2→ClO3 - + Cl - , occurs in alkaline solution. The number of electrons transferred in the balanced equation is:

After balancing the following reaction under basic conditions , how many mole equivalents of water are required and on which side of the reaction do they appear? CrO42 - (aq) + Cu (s) →Cr(OH) 3 (s) + Cu(OH) 2 (s) [Basic conditions]

After balancing the following reaction under acidic conditions , how many mole equivalents of water are required and on which side of the reaction do they appear? MnO41 - (aq) + Cl1 - (aq) →Mn2+ (aq) + Cl2 (g) [Acidic conditions]

In the oxidation-reduction reaction shown below, the number of electrons transferred is: H2O + 3 ClO - (aq) →ClO2 - (aq) + Cl2 (aq) + 2 OH - (aq)

After balancing the following reaction under acidic conditions , what is the coefficient for the species, Cl1 - ? MnO41 - (aq) + Cl1 - (aq) →Mn2+ (aq) + Cl2 (g) [Acidic conditions]

After balancing the following reaction under basic conditions , what is the coefficient for the copper? CrO42 - (aq) + Cu (s) →Cr(OH) 3 (s) + Cu(OH) 2 (s) [Basic conditions]

Which equation listed below is correct after balancing the following unbalanced equation under basic conditions ? MnO41 - (aq) + Br1 - (aq) →MnO2 (s) + BrO31 - (aq) [Basic conditions]

After balancing the following reaction under basic conditions , how many electrons are transferred? MnO41 - (aq) + Br1 - (aq) →MnO2 (s) + BrO31 - (aq) [Basic conditions]

What species becomes oxidized and what species behaves as the reducing agent in the following oxidation-reduction reaction? 2 H₂ O ( ) + Al (s) + MnO4 1 - (aq) Al(OH) 4 1 - (aq) + MnO₂ (s)

After balancing the following reaction under acidic conditions , how many electrons are transferred? Mn2+ (aq) + BiO31 - (aq) →Bi3+ (aq) + MnO41 - (aq) [Acidic conditions]

In the following balanced redox reaction: 14 HCl + K2Cr2O7 + 6 FeCl2→2 CrCl3 + 6 FeCl3 + 2 KCl + 7 H 2O

Start with the skeleton half-reaction NO3 - →NO2. When balanced in acid solution, what other species appear on the left side of the equation, in addition to NO3 -?

Given the skeleton half-reaction: Na2C2O4→CO2 + Na+ When the half-reaction is properly balanced we find that the half-reaction represents:

Start with the skeleton half-reaction NO2 - →NO3 - . When balanced in basic solution, what other species appear on the right side of the equation, in addition to NO3 - ?

In the oxidation-reduction equation (balanced) : H2O + 3 ClO - (aq) →ClO2 - (aq) + Cl2 (aq) + 2 OH - (aq)

In the properly balanced half-reaction (acid solution) for the system H₃AsO₃→H₂AsO₄^-, what else appears on the right side besides H₂AsO₄^-?

Start with the skeleton half-reaction CrO₂^-→CrO₄^{2 -}. When balanced in basic solution, what other species appear on the right side of the equation, in addition to CrO₄^{2 -}?

After balancing the following reaction under acidic conditions , what is the coefficient for the species, BiO₃^{1 -}? Mn²⁺ (aq) + BiO₃^{1 -} (aq) →Bi³⁺ (aq) + MnO₄^{1 -} (aq) [Acidic conditions]

What is the oxidizing agent in the following reaction? H₂O + 2 MnO₄^{1 -} (aq) + I^- (aq) →2 MnO₂ (s) + IO₃^{1 -} (aq) + 2 OH^- (aq)

In the redox reaction: 3 S^{2 -} + 2 MnO₄^- + 8 H₂O→3 S + 2 MnO₂ + 4 H₂O + 8 OH^- the S^{2 -} changes oxidation state to give the element S. Which statement below is true?

The redox reaction (unbalanced) , Cl₂→ClO₃^- + Cl^-, occurs in alkaline solution. The number of electrons transferred in the balanced equation is:

After balancing the following reaction under basic conditions , how many mole equivalents of water are required and on which side of the reaction do they appear? CrO₄^{2 -} (aq) + Cu (s) →Cr(OH) ₃ (s) + Cu(OH) ₂ (s) [Basic conditions]

After balancing the following reaction under acidic conditions , how many mole equivalents of water are required and on which side of the reaction do they appear? MnO₄^{1 -} (aq) + Cl^{1 -} (aq) →Mn²⁺ (aq) + Cl₂ (g) [Acidic conditions]

In the oxidation-reduction reaction shown below, the number of electrons transferred is: H₂O + 3 ClO^- (aq) →ClO₂^- (aq) + Cl₂ (aq) + 2 OH^- (aq)

After balancing the following reaction under acidic conditions , what is the coefficient for the species, Cl^{1 -}? MnO₄^{1 -} (aq) + Cl^{1 -} (aq) →Mn²⁺ (aq) + Cl₂ (g) [Acidic conditions]

After balancing the following reaction under basic conditions , what is the coefficient for the copper? CrO₄^{2 -} (aq) + Cu (s) →Cr(OH) ₃ (s) + Cu(OH) ₂ (s) [Basic conditions]

Which equation listed below is correct after balancing the following unbalanced equation under basic conditions ? MnO₄^{1 -} (aq) + Br^{1 -} (aq) →MnO₂ (s) + BrO₃^{1 -} (aq) [Basic conditions]

After balancing the following reaction under basic conditions , how many electrons are transferred? MnO₄^{1 -} (aq) + Br^{1 -} (aq) →MnO₂ (s) + BrO₃^{1 -} (aq) [Basic conditions]

What species becomes oxidized and what species behaves as the reducing agent in the following oxidation-reduction reaction? 2 H₂ O ( ) + Al (s) + MnO₄ 1 - (aq) Al(OH) 4 1 - (aq) + MnO₂ (s)

After balancing the following reaction under acidic conditions , how many electrons are transferred? Mn²⁺ (aq) + BiO₃^{1 -} (aq) →Bi³⁺ (aq) + MnO₄^{1 -} (aq) [Acidic conditions]

In the following balanced redox reaction: 14 HCl + K₂Cr₂O₇ + 6 FeCl₂→2 CrCl₃ + 6 FeCl₃ + 2 KCl + 7 H₂O

Start with the skeleton half-reaction NO₃^-→NO₂. When balanced in acid solution, what other species appear on the left side of the equation, in addition to NO₃ ^-?

Given the skeleton half-reaction: Na₂C₂O₄→CO₂ + Na⁺ When the half-reaction is properly balanced we find that the half-reaction represents:

Start with the skeleton half-reaction NO₂^-→NO₃^-. When balanced in basic solution, what other species appear on the right side of the equation, in addition to NO₃^-?

In the oxidation-reduction equation (balanced) : H₂O + 3 ClO^- (aq) →ClO₂^- (aq) + Cl₂ (aq) + 2 OH^- (aq)