Conversion And Partial Pressures

Unit conversions for Pressure Conversion factors 1 atm = 760 mm Hg or 760 torr 1 atm = 101325 pa (pascal) or 101.325 kpa (kilopascal) 1 atm = 14.69695 PSI (pound/in2) just round to 14.7 PSI 1 atm = 1.01325 bar (bar and at are very close to each other) You don’t need to memorize these conversion factors, but you do need to be able to use them. Objective #1: TLW state STP (standard temperature and pressure) Standard temperature is 0 degrees C Standard pressure is 1 atm (memorize this) Objective #2: TLW covert between different units of pressure (many of these will NOT work out perfectly!!!) Use scientific notation and sig figs!!! 1) Convert 2.00 atm to PSI 2) Convert 25.0 PSI to atm 3) Convert .500 atm to mm Hg 4) Convert 1000. torr to atm 5) Convert .05 atm to pa and kpa 6) Convert 1.23 pa to atm 7) Convert 14.5 kpa to mm Hg 8) Convert 500. PSI to pa 9) Convert 1 bar to kpa 10) Convert 1 bar to pa 11) What do you notice about bar, kpa, and pa? Objective #3: TLW use Dalton’s law of partial pressures to calculate partial pressures and total pressures (you’ll need to look up values on pg. 859)

1) Oxygen gas from the decomposition of potassium chlorate, KClO3, was collected by water displacement. The barometric pressure and the temperature during the experiment were 731.0 torr and 20.0 C respectively. What was the partial pressure of the oxygen?

2) Hydrogen gas from the reaction below: Mg + HCl  MgCl2 + H2 was collected by water displacement. The barometric pressure and the temperature during the experiment were 745.0 torr and 23.5 C respectively. What was the partial pressure of the hydrogen? (balance the equation)

3) After climbing to the summit of Mt. Everest you decide to drop a piece of dry ice in water and collect the gas via water displacement. The barometric pressure and the temperature during the experiment were 225 torr and 0.00 C respectively. What was the partial pressure of the carbon dioxide?

4) Hydrogen peroxide (H2O2) decomposes to form water and oxygen gas in accordance to this reaction: 2H2O2  2H2O + O2 The oxygen was collected by water displacement. The barometric pressure and the temperature during the experiment were 731.0 torr and 30.0 C respectively. What was the partial pressure of the oxygen? Ambient temperature can make a difference!!!