An experiment was carried out to determine the relative molecular mass (Mr) of a volatile hydrocarbon X that is a liquid at room temperature. Calculate the Mr from the data provided.
Mass of X: 194 mg; Temperature: 373 K; Pressure: 102 kPa; Volume: 72 cm3n = PV/RT [ideal gas equation]= (102 x 103 x 72 x 10-6)/(8.31 x 373) [substituting in values from question, in correct units]= 0.00237 [number of moles]Mr = mass/moles [moles equation]= 0.194/0.00237 [substituting in values, in correct units]= 82 [final answer]
