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Calculating moles and molecular mass

A steel bottle of 4.00 liters, initially evacuated, is filled with 4.00 grams of a pure gas. The bottle has an absolute pressure of 1.5375 Standard Atmospheres when the temperature is 300 Kelvin. R=0.0820 liter atm/mole K.

1) How many moles of gas does the bottle contain?

2) What's the molecular weight (in grams) of the mass?

3) If the gas is a hydrocarbon compound known to be a member of the paraffin series, CnH2n+2, what is the chemical formula of the compound?

Solution Preview

1) To solve for the number of moles of gas, we can use the ideal gas law which says that P V = n R T. This can be rewritten as n = P V / (R T) to give the number of moles of gas. Since the volume (4 liters), pressure (1.5375 atm) and temperature (300K) are known you can calculate the ...

Solution Summary

Calculating moles and molecular mass is achieved.