. Iodide ion, I- , is one of the most easily oxidized species. Balance each of the following
a.
(a)
Interpretation:
The given oxidation-reduction reaction should be balanced using the half-reaction method.
Concept Introduction:
The oxidation-reduction reaction is also known as a redox reaction. In this reaction, one reactant is oxidized and other is reduced. In balancing an oxidation-reduction reaction they must be first divided into two half reactions: one is oxidation reaction and other is reduction reaction.
The balancing of redox reaction is complicated as compared to simple balancing. It is necessary to determine the half reactions of reactants undergoing oxidation and reduction. On adding the two half-reactions, net total equation can be obtained. This method of balancing redox reaction is known as half equation method.
The following rules must be followed in balancing redox reaction by half equation method:
- Initially, redox reaction is separated into two half equations; oxidation and reduction.
- Atoms other than hydrogen and oxygen are balanced first in the unbalanced half equations.
- Oxygen atoms are balanced by addition of water on either side of the reaction.
- Hydrogen ion/s is added to balance the hydrogen atom.
- Electrons are added to balance the charge.
- Half reactions are added to get the net total equation.
- The further addition of hydroxide ion takes place on both side of the reaction, if the solution is basic in nature to neutralise the hydrogen ion present in the solution.
Answer to Problem 47QAP
Explanation of Solution
The given reaction is as follows:
The above reaction can be separated into two half reactions as follows:
Here,
To balance the reaction (1), give coefficient 2 to
Now, oxygen atom can be balanced by adding 6 water molecules to right thus,
Next step is to balance hydrogen atoms by adding 12 hydrogen ions to the left:
The last step is to balance the charge thus, 4 electrons are added to left thus,
Now, balance reaction (2) by given coefficient 2 to
Now, charge can be balanced by adding 2 electrons to the right thus,
To get the net reaction, add reaction (3) and (4) as follows:
Thus, the balanced chemical reaction is as follows:
(b)
Interpretation:
The given oxidation-reduction reaction should be balanced using the half-reaction method.
Concept Introduction:
The oxidation-reduction reaction is also known as a redox reaction. In this reaction, one reactant is oxidized and other is reduced. In balancing an oxidation-reduction reaction they must be first divided into two half reactions: one is oxidation reaction and other is reduction reaction.
The balancing of redox reaction is complicated as compared to simple balancing. It is necessary to determine the half reactions of reactants undergoing oxidation and reduction. On adding the two half-reactions, net total equation can be obtained. This method of balancing redox reaction is known as half equation method.
The following rules must be followed in balancing redox reaction by half equation method:
- Initially, redox reaction is separated into two half equations; oxidation and reduction.
- Atoms other than hydrogen and oxygen are balanced first in the unbalanced half equations.
- Oxygen atoms are balanced by addition of water on either side of the reaction.
- Hydrogen ion/s is added to balance the hydrogen atom.
- Electrons are added to balance the charge.
- Half reactions are added to get the net total equation.
- The further addition of hydroxide ion takes place on both side of the reaction, if the solution is basic in nature to neutralise the hydrogen ion present in the solution.
Answer to Problem 47QAP
Explanation of Solution
The given reaction is as follows:
The two reactions can be separated into half reactions as follows:
And,
Reaction (1) can be balanced by giving coefficient 2 to
Add 7 water molecules to the right to balance oxygen atoms thus,
Hydrogen atom can be balanced by adding 14 hydrogen ions to the left
Last step is to balance the charge, the net charge on left side is + 12 and on right side is + 6 thus, 6 electrons are added to left to balance the charge thus,
In reaction (2), iodine atom is balanced by giving coefficient 2 to
Next step is to balance the charge; two electrons are added to the right to balance the two negative charges on left side:
To get the net reaction, add reaction (3) and (4) as follows:
Thus, the balanced chemical reaction is as follows:
(c)
Interpretation:
The given oxidation-reduction reaction should be balanced using the half-reaction method.
Concept Introduction:
The oxidation-reduction reaction is also known as a redox reaction. In this reaction, one reactant is oxidized and other is reduced. In balancing an oxidation-reduction reaction they must be first divided into two half reactions: one is oxidation reaction and other is reduction reaction.
The balancing of redox reaction is complicated as compared to simple balancing. It is necessary to determine the half reactions of reactants undergoing oxidation and reduction. On adding the two half-reactions, net total equation can be obtained. This method of balancing redox reaction is known as half equation method.
The following rules must be followed in balancing redox reaction by half equation method:
- Initially, redox reaction is separated into two half equations; oxidation and reduction.
- Atoms other than hydrogen and oxygen are balanced first in the unbalanced half equations.
- Oxygen atoms are balanced by addition of water on either side of the reaction.
- Hydrogen ion/s is added to balance the hydrogen atom.
- Electrons are added to balance the charge.
- Half reactions are added to get the net total equation.
- The further addition of hydroxide ion takes place on both side of the reaction, if the solution is basic in nature to neutralise the hydrogen ion present in the solution.
Answer to Problem 47QAP
Explanation of Solution
The given reaction is as follows:
The above reaction can be separated into two half reactions as follows:
And,
In reaction (1), charge can be balanced by adding electrons. Since, there is + 1 charge on left thus, 1 electron is added to left:
Now, in reaction (2), iodine atom can be balanced by giving coefficient 2 to
The charge can be balanced by adding 2 electrons to the right thus,
To get the net reaction, add reaction (3) and (4) as follows:
Thus, the balanced chemical reaction is as follows:
Want to see more full solutions like this?
Chapter 18 Solutions
Introductory Chemistry: A Foundation
- Gold can be dissolved from gold-bearing rock by treating the rock with sodium cyanide in the presence of oxygen. 4 Au(s) + 8 NaCN(aq) + O2(g) + 2 H2O() 4 NaAu(CN)2(aq) + 4 NaOH(aq) (a) Name the oxidizing and reducing agents in this reaction. What has been oxidized, and what has been reduced? (b) If you have exactly one metric ton (1 metric ton = 1000 kg) of gold-bearing rock, what volume of 0.075 M NaCN, in liters, do you need to extract the gold if the rock is 0.019% gold?arrow_forwardTriiodide ions are generated in solution by the following (unbalanced) reaction in acidic solution: IO3(aq) + I(aq) I3(aq) Triiodide ion concentration is determined by titration with a sodium thiosulfate (Na2S2O3) solution. The products are iodide ion and tetrathionate ion (S4O6). a. Balance the equation for the reaction of IO3 with I ions. b. A sample of 0.6013 g of potassium iodate was dissolved in water. Hydrochloric acid and solid potassium iodide were then added. What is the minimum mass of solid KI and the minimum volume of 3.00 M HQ required to convert all of the IO3 ions to I ions? c. Write and balance the equation for the reaction of S2O32 with I3 in acidic solution. d. A 25.00-mL sample of a 0.0100 M solution of KIO. is reacted with an excess of KI. It requires 32.04 mL of Na2S2O3 solution to titrate the I3 ions present. What is the molarity of the Na2S2O3 solution? e. How would you prepare 500.0 mL of the KIO3 solution in part d using solid KIO3?arrow_forward1. Sometimes a reaction can fall in more than one category. Into what category (or categories) does the reaction of Ba(OH)2(aq) + H+PO4(aq) fit? acid-base and oxidation-reduction oxidation-reduction acid-base and precipitation precipitationarrow_forward
- The blood alcohol (C2H5OH) level can be determined by titrating a sample of blood plasma with an acidic potassium di-chromate solution, resulting in the production of Cr3+ (aq) and carbon dioxide. The reaction can be monitored because the dichromate ion (Cr2O72) is orange in solution, and the Cr3+ ion is green. The balanced equations is 16H+(aq) + 2Cr2O72(aq) + C2H5OH(aq) 4Cr4+(aq) + 2CO2(g) + 11H2O(l) This reaction is an oxidationreduction reaction. What species is reduced, and what species is oxidized? How many electrons are transferred in the balanced equation above?arrow_forwardThe mineral dolomite contains magnesium carbon-ate. This reacts with hydrochloric add. MgCO3(s) + 2 HCl(aq) CO2(g) + MgCl2(aq) + H2O() (a) Write the net ionic equation for this reaction and identify the spectator ions. (b) What type of reaction is this?arrow_forward2. Equal amounts (moles) of acetic acid(aq) and sodium sulfite, Na2SO3(aq), are mixed. The resulting solution is acidic basic neutralarrow_forward
- Write the net ionic equation for the reaction, if any, that occurs on mixing (a) solutions of sodium hydroxide and magnesium chloride. (b) solutions of sodium nitrate and magnesium bromide. (c) magnesium metal and a solution of hydrochloric acid to produce magnesium chloride and hydrogen. Magnesium metal reacting with HCl.arrow_forwardWrite balanced net ionic equations for the following reactions in acid solution. (a) Liquid hydrazine reacts with an aqueous solution of sodium bromate. Nitrogen gas and bromide ions are formed. (b) Solid phosphorus (P4) reacts with an aqueous solution of nitrate to form nitrogen oxide gas and dihydrogen phosphate (H2PO4-) ions. (c) Aqueous solutions of potassium sulfite and potassium permanganate react. Sulfate and manganese(II) ions are formed.arrow_forwardXenon trioxide, XeO3, reacts with aqueous base to form the xenate anion, HXeO4. This ion reacts further with OH to form the perxenate anion, XeO64, in the following reaction: 2HXeO4(aq)+2OH(aq)XeO64(aq)+Xe(g)+O2(g)+2H2O(l) Identify the elements that are oxidized and reduced in this reaction. You will note that the equation is balanced with respect to the number of atoms on either side. Verify that the redox part of this equation is also balanced, that is, that the extents of oxidation and reduction are also equal.arrow_forward
- A Describe how to prepare zinc chloride by (a) an add-base reaction, (b) a gas-forming reaction, and (c) an oxidation-reduction reaction. The available starting materials are ZnCO3, HCl, Cl2, HNO3, Zn(OH)2, NaCl, Zn(NO3)2, and Zn. Write complete, balanced equations for the reactions chosen.arrow_forwardThe amount of oxygen, O2, dissolved in a water sample at 25 C can be determined by titration. The first step is to add solutions of MnSO4 and NaOH to the water to convert the dissolved oxygen to MnO2. A solution of H2SO4 and KI is then added to convert the MnO2 to Mn2+, and the iodide ion is converted to I2. The I2 is then titrated with standardized Na2S2O3. (a) Balance the equation for the reaction of Mn2+ ions with O2 in basic solution. (b) Balance the equation for the reaction of MnO2 with I in acid solution. (c) Balance the equation for the reaction of S2O32 with I2. (d) Calculate the amount of O2 in 25.0 mL of water if the titration requires 2.45 mL of 0.0112 M Na2S2O3 solution.arrow_forwardTo analyze an iron-containing compound, you convert all the iron to Fe2+ in aqueous solution and then titrate the solution with standardized KMnO4. The balanced, net ionic equation is MnO4(aq) + 5 Fe2(aq) + 8 H3O+(aq) Mn2(aq) + 5 Fe3+(aq) + 12 H2O(l) A 0.598-g sample of the iron-containing compound requires 22.25 mL of 0.0123 M KMnO4 for titration to the equivalence point. What is the mass percent of iron in the sample?arrow_forward
- Chemistry & Chemical ReactivityChemistryISBN:9781133949640Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning
- Chemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage LearningChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage LearningChemistry: An Atoms First ApproachChemistryISBN:9781305079243Author:Steven S. Zumdahl, Susan A. ZumdahlPublisher:Cengage Learning