Question

Use the standard reduction potentials to determine what is observed at the cathode during the electrolysis...

Use the standard reduction potentials to determine what is observed at the cathode during the electrolysis of a 1.0 M solution of KBr that contains phenolphthalein. What observation(s) is(are) made?

O2 (g) + 4H+ (aq) + 4e- --> 2H2O (l) E°​ = 1.23 V

Br2 (l) + 2e- --> 2Br​- (aq) E°​ = 1.07 V

2H2O (l) + 2e- --> H2 (g) + 2OH​- E° = -0.80 V

K+ (aq) + e- --> K(s) E°​ = -2.92 V

(A) Solid metal forms

(B) Bubbles form and a pink color appears

(C) Dark red Br2 (aq) forms.

(D) Bubbles form and the solution remains colorless.

The correct answer is B. Can someone please explain why?

Science   Chemistry   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
For the following reactions and given standard reduction potentials O2(g) + 4H+(aq) + 2Cu(s)  2Cu2+(aq)...
For the following reactions and given standard reduction potentials O2(g) + 4H+(aq) + 2Cu(s)  2Cu2+(aq) + 2H2O(l) O2(g) + 4H+(aq) + 4e-  2H2O(l)       E° = 1.23 V Cu2+ + 2e-  Cu(s)    E° = 0.34 V a. Calculate E°cell b. Calculate ΔG° at 254 K
3) The corrosion of iron is an electrochemical process that involves the standard reduction potentials given...
3) The corrosion of iron is an electrochemical process that involves the standard reduction potentials given here at 25 °C. Fe2+(aq) + 2e– → Fe(s) E° = –0.44 V O2(g) + 4H+ (aq) + 4e– → 2H2O(l) E° = +1.23 V a. Calculate the voltage for the standard cell based on the corrosion reaction. 2Fe(s) + O2(g) + 4H+ (aq) → 2Fe2+(aq) + 2H2O(l) b. Calculate the voltage if the reaction in Part a occurs at pH = 4.00 but...
Calculate the equilibrium constant for each of the reactions at 25 ?C. Standard Electrode Potentials at...
Calculate the equilibrium constant for each of the reactions at 25 ?C. Standard Electrode Potentials at 25 ?C Reduction Half-Reaction E?(V) Pb2+(aq)+2e? ?Pb(s) -0.13 Mg2+(aq)+2e? ?Mg(s) -2.37 Br2(l)+2e? ?2Br?(aq) 1.09 Cl2(g)+2e? ?2Cl?(aq) 1.36 MnO2(s)+4H+(aq)+2e? ?Mn2+(aq)+2H2O(l) 1.21 Cu2+(aq)+2e? ?Cu(s) 0.16 Part A: Pb2+(aq)+Mg(s)?Pb(s)+Mg2+(aq) Express your answer using three significant figures. Part B: Br2(l)+2Cl?(aq)?2Br?(aq)+Cl2(g) Express your answer using two significant figures. Part C: MnO2(s)+4H+(aq)+Cu(s)?Mn2+(aq)+2H2O(l)+Cu2+(aq) Express your answer using two significant figures.
Constants Fe2+ + 2e− = Fe(s) E º =−0.44 V; O + 4H+ + 4e− 2H2O...
Constants Fe2+ + 2e− = Fe(s) E º =−0.44 V; O + 4H+ + 4e− 2H2O E º =−1.23 V 2)In acid solution, the half cells Fe2+(aq) | Fe(s) and O2(g) | H2O are linked to create a spontaneous, galvanic cell. a) Calculate Eºcell _____________ b) Which reaction occurs at the cathode _______________________________ c) Write the overall reaction for the cell ___________________________________ d) Write the shorthand notation for the anode (anode || cathode).
Consider the following standard reduction potentials in acid solution at 25 °C: PbI2(s) + 2e- →...
Consider the following standard reduction potentials in acid solution at 25 °C: PbI2(s) + 2e- → Pb(s) +2I-(aq) Eºred = -0.365 V Ca2+(aq) + 2e- → Ca(s)    Eºred = -2.868 V Pt2+(aq) + 2e- → Pt(s)    Eºred = 1.18 V Br2(l) + 2e- → 2Br-(aq)    Eºred = 1.066 V Which one of the following is the strongest reducing agent? 1. Pb(s) 2. Ca(s) 3. Pt(s) 4. Br-(aq) 5. Pt2+(aq)
use the appropriate standard reduction potentials to determine the equlibrium constant at 200.00 K for the...
use the appropriate standard reduction potentials to determine the equlibrium constant at 200.00 K for the following reaction under acidic conditions: 4H+(aq) + MnO2(s) + 2F2+(aq) ------> Mn2+(aq) + 2Fe3+(aq) + 2H2O(l)
Sulfuric acid is a very strong acid that can act as an oxidizing agent at high...
Sulfuric acid is a very strong acid that can act as an oxidizing agent at high concentrations (very low pH, or even negative pH values). Under standard conditions, sulfuric acid has a low reduction potential, SO42−(aq)+4H+(aq)+2e−⇌SO2(g)+2H2O(l),   +0.20 V which means it cannot oxidize any of the halides F2, Cl2, Br2, or I2. If the H+ ion concentration is increased, however, the driving force for the sulfuric acid reduction is also increased according to Le Châtelier's principle. Sulfuric acid cannot oxidize the...
± The Nernst Equation and pH Sulfuric acid is a very strong acid that can act...
± The Nernst Equation and pH Sulfuric acid is a very strong acid that can act as an oxidizing agent at high concentrations (very low pH, or even negative pH values). Under standard conditions, sulfuric acid has a low reduction potential, SO42−(aq)+4H+(aq)+2e−⇌SO2(g)+2H2O(l),   +0.20 V which means it cannot oxidize any of the halides F2, Cl2, Br2, or I2. If the H+ ion concentration is increased, however, the driving force for the sulfuric acid reduction is also increased according to Le Châtelier's...
Use standard reduction potentials (shown below) to calculate the potential of a nickel-cadmium cell that uses...
Use standard reduction potentials (shown below) to calculate the potential of a nickel-cadmium cell that uses a basic electrolyte that has a 3.2 M hydroxide concentration. Cd(OH)2(s) + 2e- → Cd(s) + 2OH-(aq) Eº = -0.83 V NiO(OH)s) + H2O(l) + e- → Ni(OH)2(s) + OH-(aq) Eº = 0.52 V
Use the standard reduction potentials shown here to answer the questions. Reduction half-reaction E∘ (V) Cu2+(aq)+2e−→Cu(s)...
Use the standard reduction potentials shown here to answer the questions. Reduction half-reaction E∘ (V) Cu2+(aq)+2e−→Cu(s) 0.337 2H+(aq)+2e−→H2(g) 0.000 A copper, Cu(s), electrode is immersed in a solution that is 1.00 M in ammonia, NH3, and 1.00 M in tetraamminecopper(II), [Cu(NH3)4]2+. If a standard hydrogen electrode is used as the cathode, the cell potential, Ecell, is found to be 0.073 V at 298 K. Part A Based on the cell potential, what is the concentration of Cu2+ in this solution?...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT