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Gas Stoichiometry. Ideal Gas Law Gas Stoichiometry. The Ideal Gas Law. Putting It All Together PV = nRT n = moles P = pressure Temp = must be in Kelvin Volume = must be in Liters Should be able to solve for any R but you won’t have to. Solving for R values. Use STP.
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Gas Stoichiometry Ideal Gas Law Gas Stoichiometry
The Ideal Gas Law • Putting It All Together • PV = nRT n = moles P = pressure Temp = must be in Kelvin Volume = must be in Liters Should be able to solve for any R but you won’t have to
Solving for R values • Use STP
PV = nRT • Straight Ideal Gas law problem: Sprinkled all over the AP => another way to get moles. 2) Problem: Got moles, Do stoich!
Sample Problem 1 • For an ideal gas, calculate the pressure of the gas if 0.215 moles occupies 338 mL at 32°C.
Sample Problem 2 • Acetic acid reacts with solid sodium carbonate. • 5.00 grams of sodium carbonate is added to 20.0 mL of 1.50 M acetic acid. What volume of CO2 is produced at 0.878 atm and 23°C?
Sample Problem 3 • Sodium metal is added to water. • If 43.2 mL of hydrogen gas are produced at 767 torr and 59°C in excess water, how many grams of sodium were reacted?
Finding the Molar Mass of a Gas • Should be provided grams of the gas • Use PV = nRT to find the moles • MM = grams moles
Manipulation of the Ideal Gas Law #1 PV = nRT n= mass mole mass so……. PV = mass RT mole mass
Manipulation of the Ideal Gas Law #2 PV = nRT n= mass mole mass P = (mass R T) (volume x mole mass) or P = (density R T) MM = DRT mole mass P
Manipulation of Ideal Gas Law • The density of a gas was measured at 1.50 atm and 27°C and found to be 1.95 g/L. Calculate the molar mass of this gas.
Dalton Law of Partial Pressures Key: Ptotal = P1 + P2 + P3 +…. The total pressure = the sum of all the partial pressures
Dalton Law of Partial PressuresManipulation Ptotal = P1 + P2 + P3 +…. Ptotal = n1RT + n2RT + n3RT +….. V V V Sum of the moles of gases; who cares what they are
Application of Dalton’s Law of Partial Pressures HUGE! Collecting pressure over water Pair Pgas Pwater
Collecting pressure over water Pair = Pgas + Pwater Pair Pgas Pwater Pwater is dependent on temperature