Synthetic balanced chemical equation of Arsphenamine(Salvarsan)

Chemistry and homework help forum.

Organic Chemistry, Analytical Chemistry, Biochemistry, Physical Chemistry, Computational Chemistry, Theoretical Chemistry, High School Chemistry, Colledge Chemistry and University Chemistry Forum.

Share your chemistry ideas, discuss chemical problems, ask for help with scientific chemistry questions, inspire others by your chemistry vision!

Please feel free to start a scientific chemistry discussion here!

Discuss chemistry homework problems with experts!

Ask for help with chemical questions and help others with your chemistry knowledge!

Moderators: Xen, expert, ChenBeier

Post Reply
Smolbrainer
Newbie
Newbie
Posts: 2
Joined: Wed Jan 04, 2023 9:54 pm

Synthetic balanced chemical equation of Arsphenamine(Salvarsan)

Post by Smolbrainer »

How do I write this as a balanced chemical equation? I am trying to write the chemical equation reduction of the substituted phenylarsonic acid with dithionite which produces Salvarsan. Check the attachment below to help you out.

I got this far but I don't even think this is even close to being right:
C6AsNH6O6+Na2S2O4+H2O—--->C12H12As2N2O2+Na2SO3+Na2SO4+H2O

Thank you!
Attachments
Screenshot_10.png
Screenshot_10.png (19.83 KiB) Viewed 3314 times
User avatar
ChenBeier
Distinguished Member
Distinguished Member
Posts: 1542
Joined: Wed Sep 27, 2017 7:25 am
Location: Berlin, Germany

Re: Synthetic balanced chemical equation of Arsphenamine(Salvarsan)

Post by ChenBeier »

Dithionite to sulfate

S2O4 2- + 4 H2O => 2 SO4 2- + 8 H+ + 6 e-

Arsenic acid to Salvarsan

2 RAsO3H2 + 8 H+ + 8 e- => RAs=AsR + 6 H2O

Nitrogroup 2 RNO2 + 12 H+ + 12 e- => 2 RNH2 + 4 H2O

Sum Reduction
2 RNO2AsO3H2 + 20 H+ + 20 e - => NH2RAs=AsRNH2 + 10 H2O

KgV of electrons = 60

10 S2O4 2- + 40 H2O => 20 SO4 2- + 80 H+ + 60 e-

6 RNO2AsO3H2 + 60 H+ + 60 e - => 3 NH2RAs=AsRNH2 + 30 H2O

Addition

6 RNO2AsO3H2 + 10 S2O4 2- + 10 H2O => 3 NH2RAs=AsRNH2 + 20 H+ + 20 SO42-

Add sodium

6 RNO2AsO3H2 + 10Na2S2O4 + 10 H2O => 3 NH2RAs=AsRNH2 + 20 NaHSO4
Smolbrainer
Newbie
Newbie
Posts: 2
Joined: Wed Jan 04, 2023 9:54 pm

Re: Synthetic balanced chemical equation of Arsphenamine(Salvarsan)

Post by Smolbrainer »

Thank you so much that was really helpful! I really appreciate it you are a life saver.

I was just wondering what does KgV of electrons mean?
User avatar
ChenBeier
Distinguished Member
Distinguished Member
Posts: 1542
Joined: Wed Sep 27, 2017 7:25 am
Location: Berlin, Germany

Re: Synthetic balanced chemical equation of Arsphenamine(Salvarsan)

Post by ChenBeier »

It is like in Mathematics. 1/2 +1/3 = ?
The kgV ( kleinste gemeinsame Vielfache = least common multiple) is 6 so convert to 3/6 + 2/6 = 5/6
The same you do with the electrons in oxidation and reduction equation.
Post Reply