Transcription of Extra Practice Mixed Gas Law Problems Answers
1 Mixed Extra gas law Practice Problems (Ideal Gas, Dalton s Law of Partial Pressures, Graham s Law) 1. Dry ice is carbon dioxide in the solid state. grams of dry ice is placed in a L chamber that is maintained at What is the pressure in the chamber after all of the dry ice has sublimed? = !1 1 ! != 849 ! P = ? V = L (3 significant figures) n = moles (3 significant figures) R = L*atm/mole*K (infinite significant figures) T = = K (4 significant figures) = = = If you used a different R, then the Answers are: 1120 torr 1120 mm Hg 149 kPa 2. A sample of chlorine gas is loaded into a L bottle at standard temperature of pressure.
2 How many moles of bromine gas are in the container? How many grams? At STP 1 mole = L Molar Mass of Chlorine (remember, it is a diatomic) = g/mole Use factor label 1 1 ! != ! 1 1 ! ! !1 != ! OR use the ideal gas law , PV = nRT P = 1 atm (infinite significant figures) V = L (2 significant figures) R = L*atm/mole*K (infinite significant figures) T = 273 K (infinite significant figures) = = 1 ( ) (273 )= ! !1 !1 != ! 3. What is the volume of grams of chlorine gas that is at a temperature of 46oC and a pressure of 694 mmHg?
3 P = 694 mmHg (3 significant figures) V = ? R = L*mm Hg/mole*K (infinite significant figures) T = 46oC = 319 K (3 significant figures) n need to calculate !1 1 ! != 3133 ! = = (319 )694 = 4. What is the molar mass of a gas that effuses times faster than Krypton? ! != ! ! A is the unknown gas (it effuses faster) B is Krypton (it effuses slower) != !" ! !"= ! !"= !" != Square both sides !" ! Rearrange and solve for mass of the unknown != !" 5. Carbon dioxide is collected over water at a temperature of 18oC.
4 The pressure of water vapor at 18oC is kPa. If the pressure of the gas collected is atm, what is the pressure of the dry gas alone? !"#$%= !"#$% !"#$%= = 1 1 = 1767 !"#$%& !"#$"!%= !"!#$ !"#$% !"#$%= = 6. What diffuses more quickly: tetracarbon decahydride or iodine? By how much? C4H10 versus I2 Molar mass of C4H10 = g/mole Molar mass of I2 = g/mole Butane will effuse more quickly because it has a smaller molar mass ! != ! ! A butane B iodine ! != = 7. What is the molar mass of a gas that effuses times faster than bromine? ! != ! ! A is the unknown gas (it effuses faster) B is Bromine (it effuses slower) !
5 = !"! ! !"!= ! !"!= !" != Square both sides !"! ! Rearrange and solve for mass of the unknown != !"! 8. A mixture of gases contains oxygen, water vapor, carbon dioxide, and argon. If the partial pressure of oxygen is atm, the partial pressure of the water vapor is 382 mmHg, the partial pressure of the carbon dioxide is 234 kPa, and the partial pressure of the argon is 143 mmHg, what is the total pressure? !!= !!!= 382 = 382 1 1 760 = 63 !"!= 234 = 234 1 1 = 997 !"= 143 = 143 1 1 760 = 157 !"!#$= !!+ !
6 !!+ !"!+ !"= + 63 + 997 + 157 = 9. What is the temperature of grams of carbon dioxide at a pressure of 1830 torr contained in a L container? P = 1830 torr (3 significant figures) V = L (3 significant figures) R = L*torr/mole*K (infinite significant figures) T = ? n need to calculate !1 1 ! != 340 ! = = 1830 ( )( ) =
