posted by Jessica on .
How do I set this up? What formula do I use? Will you please help me?
How many liters of ammonia at STP are produced when 10 g of hydrogen is combined with nitrogen?
This is a regular stoichiometry problem. Most of them are worked the same way. Print this out and memorize it.
1. Write the equation and balance it.
2. Convert grams of what you have (in this case 10 g H2) to moles. moles = grams/molar mass.
3. Using the coefficients in the balanced equation, convert moles of what you have (in this case moles H2) to moles of what you want (in this case moles NH3).
4. Now convert moles NH3 to liters. There are 22.4 L/mol; therefore, moles NH3 x 22.4 = liters NH3 at STP. Many problems ask for grams, so this last step for them would be grams = mols x molar mass.