Write balanced half-reactions for the following redox reaction: 6 Cu2+(aq)+2 Cr3+(aq)+7 H₂O(l) → 6 Cu* (aq)+Cr₂O²¯(aq)+14 H* (aq) reduction: oxidation:

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?

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

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.)

Bromine is obtained from sea water by the following redox reaction: Cl2(g) + 2 NaBr(aq) 2 NaCl(aq) + Br2() (a) What has been oxidized? What has been reduced? (b) Identify the oxidizing and reducing agents.

An electrode is prepared from liquid mercury in contact with a saturated solution of mercury(I) chloride, Hg2Cl, containing 1.00 M Cl . The cell potential of the voltaic cell constructed by connecting this electrode as the cathode to the standard hydrogen half-cell as the anode is 0.268 V. What is the solubility product of mercury(I) chloride?

Consider the following cell running under standard conditions: Fe(s)Fe2+(aq)Al3+(aq)Al(s) a Is this a voltaic cell? b Which species is being reduced during the chemical reaction? c Which species is the oxidizing agent? d What happens to the concentration of Fe3+(aq) as the reaction proceeds? e How does the mass of Al(s) change as the reaction proceeds?

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?

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)?

Describe what you expect to happen when the following solutions are electrolyzed: a aqueous Na2SO4; b aqueous KBr. That is, what are the electrode reactions? What is the overall reaction?