Question

Problem 10.67 A piece of solid carbon dioxide with a mass of 5.70 g is placed in a 10.0-L vessel that already contains air at 715 torr and 22 ∘C .

Part A After the carbon dioxide has totally vaporized, what is the partial pressure of carbon dioxide in the container at 22 ∘C ? SubmitMy AnswersGive Up Incorrect; Try Again Part B After the carbon dioxide has totally vaporized, what is the total pressure in the container at 22 ∘C ? Express your answer using four significant figures. PCO2 = atm Ptotal = atm

Answer 1

Pressure of air = P= 715 torr= 0.941 atm                          1 torr= 0.00131579atm

T=22C= 22+273= 295K

R= 0.0821 L-atm/mole-K

Volume of air= V= 10.0L

PV= nRT

n= PV/RT= 0.941x10.0/0.0821x295 = 0.388moles

number of moles of air= 0.388 moles

mass of CO2= 5.7 grams

molar mass of CO2=44 grams

number of moles of CO2 = 5.7/44= 0.1295 moles

Total number of moles= 0.388 + 0.1295= 0.5175 moles

mole fraction of CO2 = number of moles of CO2/total numbe of moles

mole fraction of CO2= 0.1295/0.5175= 0.25

PartB

Total pressure

PV= nRT

P= nRT/V = 0.5175x0.0821x295/10 = 1.25 atm

Total pressure = 1.25 atm

Part-A

partial pressure of CO2 = Total pressure x molefraction of CO2

                                       = 1.25x0.25= 0.3125 atm

Partial pressure of CO2= 0.3125 atm= 0.313 atm.