| 1. | Safety |
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2.
|
Objectives/Overview |
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3.
|
Procedures |
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4.
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Observations |
| 5. | |
| 6. | |
| 7. | |
| 8. | Conclusions |
| 9. | Calculations/Set-Ups |
| 10. | Grading Scale |
| 11. | Review Prelab Questions |
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12.
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Review Postlab Questions |
Experiment
10
The
Molar Volume of Hydrogen Gas
CALCULATIONS/SET-UPS
|
Mass
of Zinc
|
mZn
= mass of Zn and weigh boat - mass of weigh boat
|
|
Temperature of water in sink
in Kelvin
|
Twater(K) = Twater (ºC) + 273.15 |
|
Vapor
pressure of water
|
Look up and extrapolate in Appendix B |
|
Pressure of dry
H2 gas
|
PH2 = Atmospheric Pressure - Vapor pressure of water |
|
Volume of dry
H2 gas, corrected to STP
|
VH2(STP) = [(P1V1) / T1][T2/P2] |
| P1
= PH2 T1 = Twater V1 = VH2 (measured volume of hydrogen gas) |
|
| STP: P2 = 760 torr T2 = 273.15 K | |
|
Reaction of Zinc and HCl
|
A Zn(s) + B HCl(aq) -- > C H2(g) + D AnCl2(aq) |
| Be sure to write the balanced ionic equation for the above reaction on your report sheet in the appropriate location. | |
|
Moles of H2
gas generated (determined from mass of Zinc metal reacted)
|
AMZn = atomic mass of Zn |
| nH2 = [mZn / (AMZn)][(C moles H2) / (A moles Zn)] | |
|
Volume of one mole of H2
at STP (Experimental Vm)
|
Vm(experimental) = VH2(STP) / nH2 |
|
Volume of one mole of H2
at STP (theoretical Vm)
|
Vm(theoretical) = 22.414 L / mol |
|
Percent error in Vm(experimental)
|
% error = {[ | Vm(theoretical) - Vm(experimental) | ] / Vm(theoretical)} x 100 |
