[rterrain03]

How many moles of Na3C6H5O7 are formed from the number of moles of sodium bicarbonate found in 1900 g of NaHCO3?

[jcaron2]

The first step is to figure out how many moles of NaHCO3 are in 1900 g. Can you do that?

Once you know how many moles of sodium bicarbonate you have, you can figure out how many moles of sodium citrate (Na3C6H5O7) you can make. To do that you need to figure out how many bicarbonate molecules are required to make one citrate molecule for each of the different elements. For example, the citrate needs three sodium atoms, but the bicarbonate has only one. So it takes at least three bicarbonate molecules to supply enough sodium atoms to make a citrate molecule. Meanwhile, the citrate also needs five hydrogen molecules, which will require five bicarbonate molecules to supply enough. And carbon is even worse; you need six bicarbonate molecules to supply enough carbon to make one citrate molecule. Oxygen isn't so bad; you only need 7/3 (a little over two) bicarbonate molecules to supply enough oxygen.

Based upon those numbers, it's easy to see that carbon is going to be the limiting factor. You'll need six bicarbonate molecules for every citrate molecule you form. Together those six molecules will be able to supply more than enough sodium, hydrogen, and oxygen, so there will be "leftovers" (which will react to form other byproducts on their own), but that doesn't matter. A sodium citrate molecule requires six carbon atoms, so six bicarbonate molecules is what it takes.

That means that however many moles of sodium bicarbonate you found there to be in the first step, you'll only be able to make 1/6 as many moles of sodium citrate.

Does that make sense? Let us know what answer you get, and we'll tell you if you're right.

[rterrain03]

Ok Thank you that helps a lot. I found 22.6173 moles in 1900 grams of NaHCO3, is this correct? If it is then I think I would have 3 moles of sodium citrate.

[jcaron2]

Yes, 22.6 moles is the same thing I get. So moles of sodium citrate would be 22.6/6 3.8, which is probably the same thing you got. Good job!