How many liters of H2 are needed to produce 2.00g of NH3?
N2+3N2 ---> 2NH3
Here is a worked example of a stoichiometry problem. Just follow the steps. Remember, to convert grams of a gas to volume, 1 mole of a gas at STP occupies 22.4L.
http://www.jiskha.com/science/chemistry/stoichiometry.html
To determine the number of liters of H2 gas needed to produce 2.00g of NH3, we need to follow these steps:
1. Calculate the molar mass of NH3:
- N (nitrogen) has a molar mass of 14.01 g/mol.
- H (hydrogen) has a molar mass of 1.01 g/mol.
- NH3 (ammonia) has a molar mass of (14.01 g/mol) + 3(1.01 g/mol) = 17.04 g/mol.
2. Use the balanced equation to find the molar ratio between H2 and NH3:
- The balanced equation shows that 3 moles of H2 react with 2 moles of NH3.
- This means that the molar ratio between H2 and NH3 is 3:2.
3. Calculate the number of moles of NH3 that can be produced:
- Divide the given mass of NH3 (2.00g) by the molar mass of NH3 (17.04 g/mol):
Number of moles = 2.00 g / 17.04 g/mol.
4. Determine the number of moles of H2:
- Since the molar ratio between H2 and NH3 is 3:2, the number of moles of H2 is:
Number of H2 moles = (3/2) * (2.00 g / 17.04 g/mol).
5. Convert the moles of H2 to liters using the ideal gas law:
- The ideal gas law is defined as PV = nRT, where:
P = pressure (in atmospheres)
V = volume (in liters)
n = number of moles
R = ideal gas constant (0.0821 L.atm/mol.K)
T = temperature (in Kelvin)
- We need to use the ideal gas law to find the volume (V) of H2 gas at a given condition, assuming that the pressure (P) and temperature (T) remain constant.
V = n * R * T / P.
- The pressure and temperature values are not provided in the question, so we will assume standard conditions (P = 1 atm, T = 273.15 K).
- Substitute the values into the equation with n being the number of moles of H2 to find the volume of H2 gas:
Volume of H2 gas = (3/2) * (2.00 g / 17.04 g/mol) * 0.0821 L.atm/mol.K * 273.15 K / 1 atm.
- Calculate the volume to get the final answer in liters.
Note: Remember to convert the temperature to Kelvin (°C + 273.15) when using the ideal gas law.