3. In each of these reactions assign oxidation numbers to all species, and tell which substance is oxidized and which is reduced. Tell which is the oxidizing agent and which is the reducing agent. 2 Al(s) + 3 Cl2(g)  -> 2 AlCl3(s) 8 H3O+(aq) + MnO4-(aq) + 5 Fe2+(aq) -> 5 Fe3+(aq) + Mn2+(aq) + 12 H2O (I) FeS(s) + 3 NO-3(aq) +4 H3O+(aq) -> 3 NO(g) + SO42-(aq) + Fe3+(aq) + 6 H2O (l)

Four metals, A, B, C, and D, exhibit the following properties: (a) Only A and C react with 1.0 M hydrochloric acid to give H2(g). (b) When C is added to solutions of the ions of the other metals, metallic B, D, and A are formed. (c) Metal D reduces Bn+ to give metallic B and Dn+. Based on this information, arrange the four metals in order of increasing ability to act as reducing agents.

The iron content of hemoglobin is determined by destroying the hemoglobin molecule and producing small water-soluble ions and molecules. The iron in the aqueous solution is reduced to iron(II) ion and then titrated against potassium permanganate. In the titration, iron(ll) is oxidized to iron(III) and permanganate is reduced to manganese(II) ion. A 5.00-g sample of hemoglobin requires 32.3 mL of a 0.002100 M solution of potassium permanganate. The reaction with permanganate ion is MnO4(aq)+8H+(aq)+5Fe2+(aq)Mn2+(aq)+5Fe3+(aq)+4H2O What is the mass percent of iron in hemoglobin?

The Toliens test for the presence of reducing sugars (say, in a urine sample) involves treating the sample with silver ions in aqueous ammonia. The result is the formation of a silver mirror within the reaction vessel if a reducing sugar is present. Using glucose, C6H12O6, to illustrate this test, the oxidation-reduction reaction occurring is C6H12O6 (aq) + 2 Ag+(aq) + 2OH(aq) C6H12O7(aq) + 2 Ag(s) + H2O() What has been oxidized, and what has been reduced? What is the oxidizing agent, and what is the reducing agent? Tolien's test. The reaction of silver ions with a sugar such as glucose produces metallic silver. (a) The set-up for the reaction. (b) The silvered test tube

1. 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 precipitation

Consider these half-reactions: (a) Which is the weakest oxidizing agent? (b) Which is the strongest oxidizing agent? (c) Which is the strongest reducing agent? (d) Which is the weakest reducing agent? (e) Will Sn(s) reduce Ag+(aq) to Ag(s)? (f) Will Hg() reduce Sn2+(aq) to Sn(s)? (g) Name the ions that can be reduced by Sn(s). (h) Which metals can be oxidized by Ag+(aq)?

An electrolytic cell is set up with Cd(s) in Cd(NO3)2(aq) and Zn(s) in Zn(NO3)2(aq). Initially both electrodesweigh 5.00 g. After running the cell for several hours theelectrode in the left compartment weighs 4.75 g. (a) Which electrode is in the left compartment? (b) Does the mass of the electrode in the right compartmentincrease, decrease, or stay the same? If the masschanges, what is the new mass? (c) Does the volume of the electrode in the right compartment increase, decrease, or stay the same? If the volumechanges, what is the new volume? (The density of Cd is8.65 g/cm3.)

Balance each of the following equations, and classify them as precipitation, acid-base, gas-forming, or oxidation-reduction reactions. Show states for reactants and products (s, , g, aq). (a) CuCl2 + H2S CuS + HCl (b) H3PO4 + KOH H2O + K3PO4 (c) Ca +HBr H2 + CaBr2 (d) MgC12 + NaOH Mg(OH)2 + NaCl

Triiodide 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?

Balance each of the following oxidationreduction reactions by using the oxidation states method. a. C2H6(g) + O2(g) CO2(g) + H2O(g) b. Mg(s) + HCl(aq) Mg2+(aq) + Cl(aq) + H2(g) c. Co3+ (aq) + Ni(s) Co2+(aq) + Ni2+(aq) d. Zn(s) + H2SO4(aq) ZnSO4(aq) + H2(g)