Question
Can you please check if this lab experiment on gas stoichiometry is correctly answered.
Thanks,
Ray
Data & Calculations Mass of empty beaker 129.5 o oo61 males O. 16 32 Moles of Al used: Mass of Al wire: Show setup of calculation watch sig figs o.ODG1 mole, Al Moles of 271 /mole. o.oog2 moles H2 hydrogen theoretically produced in the reaction s moles H Show setup 3mole, H 1.15 YIO 2 moles A Mass of beaker with water 331.59 Mass of just the water 206 mb Volume of water collected. (this is the volume of gas produced). Read directly in a cylinder or calculate from the mass of water in the beaker assuming 1.00 g/mL You will convert mL to L to use in the Ideal Gas Law Temperature of the water: 20 ec 2 3 K Atmospheric pressure: 756. 8 torr Vapor pressure of the water at the above temperature: 5 torr 730.3 tom Subtract the vapor pressure from the atmospheric Pto give the pressure ofH2 730.3 torr Pressure of the dry hydrogen Use PV nRT to calculate "n" the experimentally determined moles of hydrogen. o, oa 3, mDles Ha Show a neat setup 624) 295N o Rob L 150.3 torr 2.3 82 60 152.3 n n actual moles theoretical moles x 100 Calculate the error error theoretical moles O. oog2 Show setup: 1.7 83 10 o Watch sig figs Questions: 1. If the amount of gas had not been corrected for the presence of water vapor, what effect would this have had on the calculated value of the actual moles of hydrogen Explain or show with a calculation
Explanation / Answer
Question (1)
If the amount of gas had not been corrected for the presence of water vapor then, pressure of hydrogen gas = 756.8 torr.
Then moles of hydrogen would be more and percentage error would decrease.
(756.8 torr) ( 0.206 L) = n ( 62.4 L torr/ mole K) (293 K)
n = 0.00852
Percent (%) error = ( 0.00852 - 0.0092 / 0.0092) x 100% = - 7.39% = -7.4%
Answers to all other questions are correct.