Chemical equation for glucose osazone and limiting reactants

[IBY]

Homework Statement

Okay, a while ago, I did a lab that had me get glucose osazone (C18-H22-N4-O4). Now, I am trying to calculate the theoretical mass of the osazone. The chemical equations goes as follows:

C6-H5-N2-H3*HCl + Na-C2-H3-O2*H2-O ------> C6-H5-N2-H3 + H-C2-H3-O2 + Na-Cl + 3(H2-O)

After that:
C6-H12-O6 + 3(C6-H5-N2-H3) --------> C18-H22-N4-O4 + C6-H5-N-H2 + N-H3 + 2(H2-O)

I found the limiting reactants in the first equation for Phenylhydrazine (C6-H5-N2-H3), but the thing is, in the second equation, 2 mols of phenylhydrazine gets used for osazone (C18-H22-N4-O4) and water, and the third mole decomposes into the ammonia (N-H3) and aniline (C6-H5-N-H2). So the part I am having trouble is, should I use the ration 2:1 from phenylhydrazine to osazone or keep the 3:1 ration in order to find the theoretical yield?

 

[chemisttree]

Homework Statement

Okay, a while ago, I did a lab that had me get glucose osazone (C18-H22-N4-O4). Now, I am trying to calculate the theoretical mass of the osazone. The chemical equations goes as follows:

C6-H5-N2-H3*HCl + Na-C2-H3-O2*H2-O ------> C6-H5-N2-H3 + H-C2-H3-O2 + Na-Cl + 3(H2-O)

After that:
C6-H12-O6 + 3(C6-H5-N2-H3) --------> C18-H22-N4-O4 + C6-H5-N-H2 + N-H3 + 2(H2-O)

I found the limiting reactants in the first equation for Phenylhydrazine (C6-H5-N2-H3), but the thing is, in the second equation, 2 mols of phenylhydrazine gets used for osazone (C18-H22-N4-O4) and water, and the third mole decomposes into the ammonia (N-H3) and aniline (C6-H5-N-H2). So the part I am having trouble is, should I use the ration 2:1 from phenylhydrazine to osazone or keep the 3:1 ration in order to find the theoretical yield?

If instead of making the phenylhydrazine you used, you obtained it from a bottle... which ratio would you use?

Remember that the first reaction is essentially a neutralization reaction... the phenylhydrazine hydrochloride is free-based with sodium acetate. If I discover a way to do this that requires 20 moles of the the hydrochloride to my newly-discovered base (capable of neutralizing 20 moles of the hydrochloride!), will we all have to go back and rewrite every paper ever published that used sodium acetate for the job?

 

[Blueshift5]

First of all, great job on conducting a lab on glucose osazone and determining its theoretical mass! Now, to answer your question, the limiting reactant in a chemical reaction is the one that is completely consumed and therefore determines the maximum amount of product that can be formed. In this case, it seems that phenylhydrazine is the limiting reactant, as it is completely used up in the first equation and only 2 moles are needed for the formation of osazone in the second equation. Therefore, you should use the 2:1 ratio of phenylhydrazine to osazone in order to determine the theoretical yield. This means that for every 2 moles of phenylhydrazine used, 1 mole of osazone will be formed. I hope this helps clarify your confusion and good luck with your calculations!