Posted by fru on Monday, September 22, 2008 at 3:00pm.
Ca(H2PO4)2 and NaHCO3 are ingredients of baking powder which react with each other to produce CO2, thereby causing dough or batter to rise:
Ca(H2PO4)2 (s) + NaHCO3 (s) >
CO2 (g) + H2O (g) + CaHPO4 (s) + Na2HPO4 (s) (unbalanced)
If the baking powder contains 39 % NaHCO3 and 51 % Ca(H2PO4)2 by mass,
What volume (in Litres) of CO2 is produced from 1.00 g baking powder, assuming that 1 mol of CO2 occupies 63.7 L at 177 oC (a typical baking temperature)?

chem  DrBob222, Monday, September 22, 2008 at 3:13pm
1. Balance the equation.
2. Convert 1.00 g baking powder to g of each ingredient by multiplying by the percentage (converted of course to a decimal).
3. This is a limiting reagent problem (probably) so
a. Convert g Ca(H2PO4)2 to mols.
b. Convert g NaHCO3 to mols.
4. Convert mols Ca(H2PO4)2 to mols CO2. Also, convert mols NaHCO3 to mols CO2. If the two answers are the same then then is not a limiting reagent problem and you may use the number of mols CO2. If the two numbers are not the same, the smaller number is the correct number to use and that reagent is the limiting reagent.
5. Convert mols CO2 to liters using your conversion fator in the problem.
Post your work if you get stuck.