could someone please help me with this question cause my teacher didnt explain it well......
What is the pressure in a 14.0-L cylinder filled with 31.2 g of oxygen gas at a temperature of 312 K?
What is the pressure in a 14.0-L cylinder filled with 31.2 g of oxygen gas at a temperature of 312 K?
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Anytime you're given a gas problem that has only one set of conditions of temperature, pressure and volume (called static conditions), you will need to use the universal gas law: PV = nRT - pressure times volume = moles times the universal gas constant times the temperature. In using this relationship, pressure must be in atmospheres, volume in liters, and temperature in kelvins. The value for the constant R is 0.0821-L*atm/mol*K. In this problem, we're looking for pressure - P, so P = nRT/V.
We're not give the moles of oxygen but we can get it by dividing the mass by the molar mass
n = m/MM ---> P = mRT / (MMxV) ---> (31.2-g x 0.0821-L*atm/mol*K x 312 K) / (32.0-g/mol x 14.0-L) -------------> P = 1.78 atmospheres of pressure
We're not give the moles of oxygen but we can get it by dividing the mass by the molar mass
n = m/MM ---> P = mRT / (MMxV) ---> (31.2-g x 0.0821-L*atm/mol*K x 312 K) / (32.0-g/mol x 14.0-L) -------------> P = 1.78 atmospheres of pressure