Limiting Reagant Theoretical Yield Percent Yield Chemistry? 10 Points!

I'm having trouble answering this homework question. Could you tell me how to do it because I keep getting the wrong answer! I already have all the answers but I can't get to them.

Consider the reaction:
3NO2 (g) + H2O (l) --->2HNO3 (g) + NO (g)

1. If 12.9 L of NO2 (g), measured at STP is allowed to react with 14.1 g of H2O, choose the limiting regent. Answer is either NO2 or H2O

2. Find the theoretical yield of HNO3 in grams

3. If 15.4 g of HNO3 forms, what is the percent yield?

N = 14 g

O = 16 g

NO2 = 32 g + 14 g = 46 g

this means one mole has 46 g

if we have 12.9 L at Stp we have x moles
if we have 22.4 L at Stp we have 1 mole

x = 12.9/22.4 = 0.58 moles

H2O has mass of 2+ 16 = 18 g/mole

if we have 14.1 g/18 = 0.78 moles H20

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1) you can see we will use up the NO2 first because we need 3 moles each for the products

2) to produce 2 moles of HNO3 we need 3 moles of NO2

since we have 0.58 moles NO2 we will produce

0.58 * 2/3 = 1.16/3 = 0.387 moles of HNO3 will be produced

HNO3 = 1g + 14+ 48 = 63 g

0.387*63 = 24.4 g

3) if we produce only 15.4 g

we have a percentage yield of 15.4/24.4 = 0.63 or 63 percent yield


good luck