Sciencemadness Discussion Board

Equation Balancing with Subsalicylate

Hexavalent - 27-3-2012 at 13:34

This has been pestering me for ages, cannot seem to work it out . . .online equation balancers seem to be no good either.

C7H5BiO4 + HCl --> BiCl3 + C7H6O3

I thought that perhaps it had something to do with that the bismuth subsalicylate starting product has no confirmed formula .. . it's exact structure is apparently not known.

Help?

[Edited on 27-3-2012 by Hexavalent]

[Edited on 27-3-2012 by Hexavalent]

watson.fawkes - 27-3-2012 at 15:11

Quote: Originally posted by Hexavalent  
This has been pestering me for ages, cannot seem to work it out . . .online equation balancers seem to be no good either.

C7H5BiO4 + HCl --> BiCl3 + C7H6O3

I thought that perhaps it had something to do with that the bismuth subsalicylate starting product has no confirmed formula .. . it's exact structure is apparently not known.
That equation can't be balanced. It's some simple algebra. The first three coefficients must be as thus, balancing BiCl3: x * C7H5BiO4 + 3x * HCl --> x * BiCl3 + y * C7H6O3. Balancing C, we get 7x = 7y, implying x = y. Balancing H, we get the relationship 5x + 3x = 6y, which is consistent with balanced C only if x = y = 0. Balancing O, we get 4x = 3y, which is non-trivially consistent with balanced H but not with balanced C.

So you're missing either some reagents or products, or both, or need to start over.

arsphenamine - 27-3-2012 at 19:29

Quote: Originally posted by Hexavalent  
This has been pestering me for ages, cannot seem to work it out . . .online equation balancers seem to be no good either.

C7H5BiO4 + HCl --> BiCl3 + C7H6O3

I thought that perhaps it had something to do with that the bismuth subsalicylate starting product has no confirmed formula .. . it's exact structure is apparently not known.


While the structure may be a large cluster, the simple molecule is good enough for rough stoichiometry.

Inspect the <b>simplified structure</b> at wikipedia.

There is an OH ligand on the Bi that protonates, then leaves as water.

So to amend the equation, <b>add water.</b>

C<sub>7</sub>H<sub>5</sub>BiO<sub>4</sub> + 3(HCl) --> <b>H<sub>2</sub>O</b> + BiCl<sub>3</sub> + C<sub>7</sub>H<sub>6</sub>O<sub>3</sub>



Hexavalent - 28-3-2012 at 07:13

Thanks a lot arsphenamine and watson, you may have guessed that I am extracting bismuth from pepto-bismol:)