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image.png.52dc0e68342b9cb75be10528b9029a28.png

 

My  answers (a) 

The balanced reaction equation is 2VO2+  + 3Zn  + H2O ⇌  3ZnO + 2VO + 2H+

[math]E^{\circ}_{rxn} = E^{\circ}_{VO_2^+} - E^{\circ}_{Zn} = 1.00 V - (-0.76) V = 1.76 V [/math]

 

(b) [math] E = E^{\circ}_{Cu} - \frac{0.059}{n} \log \frac{1}{[Cu^{2+}]}[/math]

[math] E= 0.34 V - \frac{0.059}{2}\log \frac{1}{[0.10]}= 0.31 V [/math]

 

 I am working on other  questions.

Any chemistry help will be accepted.

11 minutes ago, Dhamnekar Win,odd said:

image.png.52dc0e68342b9cb75be10528b9029a28.png

 

My  answers (a) 

The balanced reaction equation is 2VO2+  + 3Zn  + H2O ⇌  3ZnO + 2VO + 2H+

Erxn=EVO+2EZn=1.00V(0.76)V=1.76V

 

(b) E=ECu0.059nlog1[Cu2+]

E=0.34V0.0592log1[0.10]=0.31V

 

 I am working on other  questions.

Any chemistry help will be accepted.

Jolly good.

I'm not sure we ought to be offering to check all your answers, quite apart from the effort it requires (at least speaking for myself). If you've got specific queries, we can try to help with those.

 

 

  • Author

 I want to correct my answer to (a) The balanced reaction  is 2VO2+  + Zn0  + 2H ⇌  2VO2+   +  Zn2+   + H2O

 

Answer to (c) Reduction: [math]E = E^{\circ}_{Ag} - \frac{0.059}{n}\log{ \frac{1}{[Ag^+]}}= 0.80 V - \frac{0.059}{1} \log{\frac{1}{[0.035]}} =  0.71 V[/math]

Oxidation: [math]E= E^{\circ}_{Fe} - \frac{0.059}{n} \log {\frac{[Fe^{2+}]}{[Fe^{3+}]}}= 0.77 V - \frac{0.059}{1} \log{\frac{[0.0010]}{[0.010]}} = 0.83 V[/math]

Ecell = Ered  - Eox = 0.71 - 0.83 = -0.12 V  

  • Author

I am doubtful about my answer to (d).

My attempt to answer (d):

Reduction: E = E°AgCl  - [math]\frac{0.059}{n} \log {[Cl^-]} = 0.22 V  - \frac{0.059}{1} \log{[0.20]} = 0.26 V[/math] 

Oxidation: E= E°TiO2+  - [math]\frac{0.059}{n} \log {\frac{[Ti^{3+}]}{[Ti^{2+}] [H^+]^2}} [/math] =[math] 0.10 V - \frac{0.059}{1}\log {\frac{[0.010]} {[0.20][0.0020]^2}}= -0.14 V [/math]

Ecell   = Ered  - Eox = 0.26 V - (-0.14 V) = 0.40 V Is this answer correct?

Edited by Dhamnekar Win,odd

20 hours ago, Dhamnekar Win,odd said:

I want to correct my answer to (a) The balanced reaction  is 2[[VO2]=4O]+  + Zn0  + 2H ⇌  2VO[2O]2+   +  Zn2+   + H2O[3O]

 

23 hours ago, Dhamnekar Win,odd said:

The balanced reaction equation is 2[[VO2=4O]]+  + 3Zn  + H2O[5O] ⇌  3ZnO[3O] + 2VO[} + 2H+

Edited by NTuft

43 minutes ago, NTuft said:

 

I've not seen that method of mass accounting before, well done for spotting the issue and presenting it.  +1

However perhaps you should explain the meaning of your square brackets, some may have difficulty working it out for themselves.

A standard technique in editorialization is to insert [Ed: ]

How can you operate latex on this site, or where would you recommend I find it, please.

Edited by NTuft
coding

  • Author
7 hours ago, NTuft said:

 

  Hi, 

   Thanks for finding out the fault in  my answer.

  Now, I rewrite the corrected balanced  reaction 2VO2+  + Zn0  + 4H+  ⇌ 2VO2+  + Zn2+  + 2H2

  • Author
12 hours ago, Dhamnekar Win,odd said:

  Hi, 

   Thanks for finding out the fault in  my answer.

  Now, I rewrite the corrected balanced  reaction 2VO2+  + Zn0  + 4H+  ⇌ 2VO2+  + Zn2+  + 2H2

If I write the balanced equation as 2VO2+  + Zn0  + 2H+ ⇌ 2VO2+  + Zn2+O-2 + H2O

Is this correct? 

  • Author

Answer to question(d):

                                                      Co3+                         +                 V2+                         →                      Co2+                          +                      V3+

image.thumb.png.70f3bef09b7f3e021dedc8a584779261.png 

 

Defined redox couple is  Co3+/Co2+ system

[math] [Co^{2+}] = \frac{0.0050 mol}{0.200L} =0.025 M, [Co^{3+}]= \frac{0.010 mol}{0.200 L}=0.050 M, E_{sol}= E^{\circ}_{Co} -\frac{0.059}{n} \log{\frac{[Co^{2+}]}{[Co^{3+}]}} = 1.82 V - \frac{0.059}{1}\log{\frac{[0.025]}{[0.050]}} =1.84 V [/math]

 

 

Edited by Dhamnekar Win,odd

On 5/3/2022 at 10:12 PM, Dhamnekar Win,odd said:
On 5/3/2022 at 10:04 AM, Dhamnekar Win,odd said:

Now, I rewrite the corrected balanced  reaction 2VO2+  + Zn0  + 4H+  ⇌ 2VO2+  + Zn2+  + 2H2

If I write the balanced equation as 2VO2+  + Zn0  + 2H+ ⇌ 2VO2+  + Zn2+O-2 + H2O

Is this correct? 

I do not know.

Perhaps split apart the reduction from the oxidation reaction.

What is oxidized, what is reduced? Is the start => change  of the solution set-up to allow this reaction? 

Remember they want the E°.

Edited by NTuft

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