Question

When sodium and chromium are the two available cations, using the activity series for oxidation half-reactions,...

When sodium and chromium are the two available cations, using the activity series for oxidation half-reactions, determine and write the chemical equation.

Na(s)---->Na^+ (aq) + e^ -

Cr(s)----> Cr^3+ (aq) + 3 e^ -

0 0
Add a comment Improve this question Transcribed image text
Answer #1

The standard reduction potential values for the reduction of Na+(aq) and Cr3+(aq) are

Na+(aq) + 1e-  ----------------> Na(s), E0  = - 2.71V

Cr3+(aq) + 3e- ---------------> Cr(s), E0  = - 0.74 V

Since the standard reduction potential value is more for Cr3+(aq) , Cr3+(aq) will be reduced to Cr(s) and acts as an oxidizing agent, whereas Na(s) will be oxidized to Na+(aq) and acts as reducing agent.

Hence the half-cell rectionsa are

Oxidation half-cell: 3Na(s) --------------> 3Na+(aq) + 3e- ,  E0(oxi) = -(- 2.71V) = +2.71V

Reduction half-cell: Cr3+(aq) + 3e- ---------------> Cr(s), E0(red) = - 0.74 V

Hence the complete cell reaction can be written as

3Na(s) + Cr3+(aq) + 3e- ------------->  3Na+(aq) + 3e- +Cr(s), E0 (cell) =  E0(oxi) + E0(red) = +2.71V+ ( - 0.74 V)

or

3Na(s) + Cr3+(aq)-------------> 3Na+(aq) +Cr(s), E0 (cell) = 1.97V (answer)

Add a comment
Know the answer?
Add Answer to:
When sodium and chromium are the two available cations, using the activity series for oxidation half-reactions,...
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. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions
ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT