Finding the mass of a volatile liquid?
Unit not generating cold-enough air? Check the temp at the vents.
If you have a 20 degree difference at nightI doubt it's your chargeI'd start by turning the breaker off or pulling the disconnect to the condenserThen give the condenser coil a good washing.
Check the vent filter firstThat will affect the cooling of the houseSecond check for ice or frost around the coils or the tubing that leads into the houseThat indicates the unit is low on freon.
Maybe not enough insulation around the ducts, maybe the unit outside is facing the sun or has air flow obstructedA properly vented attic makes a big differenceAlso check to see where the condensate goesThe unit inside has to be able to drain condensate outside to remove enough humidity to cool the airIf the air is saturated it won't cool.
You have a big problem: the tube with the cooled gas sample should weigh MORE than the empty tubeYour results are (a) wrong or (b) switchedThe tube in hot water is filled with the vapor, this is condensed to a weighed amount of liquidUsing the gas laws you can determine the molecular weight of the liquid The tube and liquid cannot weigh less than the empty test tube.
