NH4NO3 (aq) + (heat) --> 2 H20 (l) + N2 (g)

Calculate the mass in grams of ammonium nitrate that must be used to produce 1.50 L of nitrogen gas collected over water at 30°C and 748 torr. At 30°C, PH20 = 31.8 mmHg. Find the moles of nitrogen gas.

Use PV = nRT to solve for n = moles N2 needed at STP.

For P, use (748-31.8/760) and don't forget T must be in kelvin.
Then use this example to solve for grams NH4NO3.
http://www.jiskha.com/science/chemistry/stoichiometry.html

To find the moles of nitrogen gas (N2), we'll need to use the ideal gas law equation: PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.

First, let's convert the units into the appropriate ones for the ideal gas law equation:
- Convert the temperature from Celsius to Kelvin: 30°C + 273.15 = 303.15 K.
- Convert the pressure from torr to atm: 748 torr / 760 torr/atm ≈ 0.9842 atm.

Now we can calculate the number of moles of nitrogen gas:
n = PV / RT,
where P = 0.9842 atm, V = 1.50 L, R = 0.0821 L·atm/(mol·K), and T = 303.15 K.

n = (0.9842 atm) * (1.50 L) / (0.0821 L·atm/(mol·K) * 303.15 K),
n ≈ 0.0583 moles

So, the number of moles of nitrogen gas produced is approximately 0.0583 moles.

Next, we need to determine the stoichiometry of the reaction to find the amount of ammonium nitrate (NH4NO3) required to produce this amount of nitrogen gas.

Based on the balanced equation:
NH4NO3 (aq) + heat → 2 H2O (l) + N2 (g),

we can see that for every 1 mole of NH4NO3, we produce 1 mole of N2.

Therefore, the amount of ammonium nitrate required is also approximately 0.0583 moles.

To find the mass of ammonium nitrate, we need to know its molar mass. The molar mass of NH4NO3 is:
(1 * molar mass of N) + (4 * molar mass of H) + (3 * molar mass of O) = 80.04 g/mol.

Finally, we can calculate the mass of ammonium nitrate:
Mass = moles * molar mass = 0.0583 moles * 80.04 g/mol ≈ 4.66 grams.

Therefore, approximately 4.66 grams of ammonium nitrate must be used to produce 1.50 L of nitrogen gas collected over water at 30°C and 748 torr.