Question

For the half reactions, determine if hydrogen sulfide can be oxidized by hydrogen peroxide. H2S →...

For the half reactions, determine if hydrogen sulfide can be oxidized by hydrogen peroxide.

H2S → S + 2H+ + 2e-     Eo = -0.14 V

H2O2 + 2H+ + 2e-   → 2H2O Eo = 1.776 V

Also, determine the equilibrium constant for the reaction. Assume a water temperature of 25oC.

Homework Answers

Answer #1

The two half cell reactions are

Oxidation reaction

H2S = S + 2H+ + 2e-

Eox = -0.14 V

Oxidation number of S in H2S = - 2

S is oxidized in the reaction from - 2 to 0

Reduction reaction

H2O2 + 2H+ + 2e- = 2H2O

Ered = 1.776 V

Oxidation number of O in H2O2 = - 1

Oxidation number of O in H2O = - 2

O is reduced from - 1 to - 2

Overall cell reaction

H2S + H2O2 = S + 2H2O

H2S is oxidized by H2O2 and gives S and water

E° = Eox + Ered

= - 0.14 + 1.776

= 1.636 V

Free energy G° = - nFE°

= - 2 x 96500 C/mol x 1.636 V

= - 315748 J/mol

Equilibrium constant

K = exp (-G°/RT)

= exp (315748/8.314*298)

= exp(127.44)

= 2.22 x 10^55

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Hydrogen peroxide, H2O2, can act as both an oxidising agent or a reducing agent according to...
Hydrogen peroxide, H2O2, can act as both an oxidising agent or a reducing agent according to the following half reactions: Oxidising agent: H2O2(aq) + 2H+(aq) +2e– → 2H2O(l) Reducing agent: H2O2(aq) → O2(g) + 2H+(aq) 2e– What simple visual cue would indicate a reaction where H2O2 is acting as a reducing agent? formation of water increase in pH appearance of electrons bubbles of gas
Write the two half-reactions involved in the disproportionation of hydrogen peroxide to water and diatomic oxygen....
Write the two half-reactions involved in the disproportionation of hydrogen peroxide to water and diatomic oxygen. Balance the equation . Calcuate Eo for the overall reaction.
Hydrogen sulfide (H2S) is a problem in sewage because it can be oxidized to form sulfuric...
Hydrogen sulfide (H2S) is a problem in sewage because it can be oxidized to form sulfuric acid and corrode pipes and because hydrogen sulfide gas produces an unpleasant odor (rotten egg smell). A team of engineers in Denver (total atmospheric pressure 0.92 atm) is worried about the hydrogen sulfide concentrations in a sewage system. They take a sample of air in the empty space of a partially filled sewage pipe and measure a H2S concentration of 313 ppm by volume...
Hydrogen sulfide (H2S) is a common and troublesome pollutant in industrial wastewaters. One way to remove...
Hydrogen sulfide (H2S) is a common and troublesome pollutant in industrial wastewaters. One way to remove H2S is to treat the water with chlorine, in which case the following reaction occurs: H2S(aq)+Cl2(aq)?S(s)+2H+(aq)+2Cl?(aq) The rate of this reaction is first order in each reactant. The rate constant for the disappearance of H2S at 28?C is 3.5×10?2M?1s?1. If at a given time the concentration of H2S is 2.0×10?4 M and that of Cl2 is 2.8×10?2 M , what is the rate of...
Consider the decomposition of hydrogen peroxide to form water and oxygen, 2H2O2(g) ⇋ 2H2O(g) + O2(g)...
Consider the decomposition of hydrogen peroxide to form water and oxygen, 2H2O2(g) ⇋ 2H2O(g) + O2(g) A researcher places 2.86 moles of H2O2 in a volume of 5.50L at 307 ℃. After equilibrium was reached, 2.00 moles of H2O2 remained. Reactants and products → [H2O2] [H2O] [O2] Initial Change Equilibrium Use the information given to fill out the ICE table above. Each box must be completed. Determine the equilibrium concentration of each component of the reaction. Using the values from...
17. Given the following two half-cell reactions and their half-cell potentials: Fe3+ + e --> Fe2+...
17. Given the following two half-cell reactions and their half-cell potentials: Fe3+ + e --> Fe2+ Eo = 0.68 V Cr2O72- + 14H+ + 6e– --> 2 Cr3+ + 7H2O E° = 1.33 V a. Write the balanced full-cell reaction for a spontaneous reaction and determine the Eo cell ([H+ ] = 1.0 M): Balanced full-cell reaction: Eo cell: Answer: 0.65 V (How they got that?) b) What’s the equilibrium constant at room temperature ? Answer: K = 8.66 x...
Elemental sulfur can be recovered from gaseous hydrogen sulfide through the reaction: 2 H2S (g) +...
Elemental sulfur can be recovered from gaseous hydrogen sulfide through the reaction: 2 H2S (g) + SO2 (g) ® 3 S (s) + 2 H2O (l) What volume of H2S (in L, at 0.00°C and one atm) is required to produce 2.00 kg of sulfur by this process?
Consider the half reactions below. Cu 2+ (aq) + 2 e- -----> Cu (s) Eo =...
Consider the half reactions below. Cu 2+ (aq) + 2 e- -----> Cu (s) Eo = 0.34 V MnO4 - (aq) + 4 H+ (aq) + 3 e- -----> MnO2 (s) + 2 H2O (l) Eo = 1.68 V A. What is the standard cell potential for a voltaic cell comprised of these two half reactions? B. What is the equilibrium constant for this reaction at 25 oC? C. How is the magnitude of the equilibrium constant consistent with a...
We are absorbing hydrogen sulfide at 15°C into water. The entering water is pure. The feed...
We are absorbing hydrogen sulfide at 15°C into water. The entering water is pure. The feed gas contains 0.0012 mole frac hydrogen sulfide and we want to remove 97% of this in the water. The total gas flow rate is 10 kmol/h. The total liquid flow rate is 2000 kmol/h. Total pressure is 2.5 atm. You can assume that total liquid and gas flow rates are constant. Equilibrium data are in Table 12-1. a. Calculate the outlet gas and liquid...
Assume you are constructing a Galvanic cell based on the half-reactions between Zn2+(aq)/Zn(s) and Ag+(aq)/Ag. The...
Assume you are constructing a Galvanic cell based on the half-reactions between Zn2+(aq)/Zn(s) and Ag+(aq)/Ag. The standard reduction potentials are given below. Ag+ (aq) + e- Ag (s) Eo = 0.80 V Zn2+ (aq) + 2 e- Zn(s) Eo = -0.76 V Write a balanced chemical REDOX equation and determine the Eo for the cell. What will be observed at the cathode and at the anode? Is the reaction thermodynamically favored? Explain.