A student devised an experiment to determine the molar mass of an unknown gas X. Firstly, he filled a glass gas syringe (accurate to ± 0.5 cm3 ) with 100 cm3 of air then placed a rubber seal over the nozzle and weighed the syringe. He then emptied the gas syringe, refilled it with 100 cm3 of the unknown gas X, replaced the rubber seal and reweighed the syringe. Finally, he measured the temperature of the room. He obtained the following data: Mass of syringe + 100 cm3 of air = 186.293 ± 0.001 g Mass of syringe + 100 cm3 of unknown gas X = 186.358 ± 0.001 g Temperature = 20.0 ± 0.5 o C In order to calculate the mass of the unknown gas X the student made the following assumptions: • The atmospheric pressure = 100 kPa • Air contains 80% nitrogen and 20% oxygen by volume so has a ‘molar mass’ equivalent to 28.8 g mol-1 . • Due to Archimedes’ Principle, a syringe containing 100 cm3 of air appears to have the same mass as a syringe containing 0 cm3 of air. (a) Determine the mass of 100 cm3 of air at 20 o C. [2] (b) Determine the mass of 100 cm3 of X at 20 o C. [1] (c) Show that the molar mass of X = 44.7 g mol-1 [1] (d) The accepted value for the molar mass of X is 44.0 g mol-1 . Calculate the percentage error in the student’s result. [1] (e) Identify, with a reason, the piece of equipment used that had the largest percentage uncertainty associated with it.
A student devised an experiment to determine the molar mass of an unknown gas X. Firstly,...
Post Lab #1 A student was assigned the task of determining the molar mass of an unknown gas. The student measured the mass of a sealed 843 mL rigid flask that contained dry air. The student then flushed the flask with the unknown gas, resealed it, and measured the mass again. Both the air and the unknown gas were at 23.0°C and 750. torr. The data for the experiment are shown in the table below. Volume of sealed flask 843...
The molar mass of an unknown gas was measured by an effusion experiment. It was found that the unknown gas effused at a rate of 2.7 x 10^-6 mol/hr, whereas the nitrogen gas effused at a rate of 3.3 x 10^-6 mol/hr. What is the molar mass of the gas?
Experiment 12: Generating Hydrogen Gas Part B: Molar mass of unknown metal Unknown #: Mass of unknown metal (X) .29 Volume of H2 gas L mL Temperature of H; gas 20 mm к C Atmospheric pressure (see barometer) Vapor pressure of water mmHg Partial pressure of H; gas mmHg atm Using PV-nRT and your data, calculate the moles of hydrogen gas produced in the experiment: l e epl8 moles H Convert moles of hydrogen gas to moles of the metal...
Determine the molar mass of an unknown gas, if that unknown gas effuses via an orifice at a rate 5.42 x 10^-9 mol/s, and methane (CH4) effuses through the same orifice at the rate of 1.30 x 10^-8 mol/s, both gases having the same temperature and pressure.
Calculate the % error if a student completes the molar mass of ethanol experiment and determine the molar mass to be 49.19 g/mol when the actual molar mass of ethanol is 46.07 g/mol. (show your work) % error = |Experimental value - Actual value|/ Actual value x 100.
A sample of N2 gas is contaminated with a gas (A) of unknown molar mass. The partial pressure of each gas is known to be 200. torr at 25°C. The gases are allowed to effuse through a pinhole, and it is found that gas A escapes at 2 times the rate of N2. The molar mass of gas A is: 56 g/mol 14.01 g/mol 7.00 g/mol 112 g/mol none of these
Question 18 of 24 Submit What is the molar mass of an unknown gas with a density of 2.00 g/L at 1.00 atm and 25.0 °C? g/mol 4 5 +/- x 100 Tap here or pull up for additional resources
A student determined the molar volume of CO2 gas using the procedure described in this experiment? He collected the following data. mass of empty Mylar balloon and fastener,g 3.03 mass of Mylar balloon, fastener, and CO2 gas, g 3.99 volume (capacity) of Mylar balloon, mL 1730 barometric pressure, in. Hg = 28.96 laboratory temperature, C = 22 a)express the pressure in atmospheres. [Note: 1 atm = 29.92in. Hg] b)express the temperature in Kelvin c)express the volume of the balloon in...
Question 1 4 pts The molar mass of an unknown gas was measured by an effusion experiment. It was found that it took 64.1 seconds for the gas to effuse, where as nitrogen gas required 48.0 seconds. The molar mass of the gas is g/mol.
N2 effuses 2.16 times faster than an unknown gas. What is the molar mass of the unknown gas? 11.4 g/mol 60.5 g/mol 168 g/mol 131 g/mol