Molar Mass of a Volatile Gas Lab Report Example | Topics and Well Written Essays - 500 words

Molar Mass of a Volatile Gas - Lab Report Example The atmospheric pressure, which was assumed to be equal to the pressure of the volatile gas, was also measured and recorded. When all the liquid had evaporated, cold water was run over the flask to facilitate the cooling of the vapor. The mass of the flask, aluminum foil as well as the condensed vapor was then determined. It was assumed that the mass of the condensed fluid was equivalent to the vapor that filled the flask. The molar mass of the gas was then computed using the ideal gas law. The number of moles in the unknown sample was calculated from the formula n=PV/RT where n was the number of moles, P was the pressure of the gas, V was the volume of the gas, R was the gas constant (8.21x10-2 L atm mol-1 K-1), and T was the temperature in Kelvin (Slowinski, Wosley and Rossi 55). The experimental molar mass was lower than 32, which was the actual molar mass of the unknown gas. The low experimental value could be due to experimental errors. For example, it was possible that there was condensed vapor in the foil cover, which interfered with the accuracy of the measurements. One other possibility that led to the disparities in the experimental molar mass of the unknown gas and the actual value was deviations from the ideal gas law. It was possible that the gas did not behave as described by the ideal gas law hence leading to the disparities in the two values. It was also possible that excess vapor escaped from the flask leading to an underestimation of the mass of the condensed liquid and the subsequent molar mass. Overall, the experiment gave an estimation of the molar mass of the unknown gas using the ideal gas law. Therefore, it was concluded that the ideal gas law was a useful equation in describing the behavior of