Question

Determine the number of moles of each gas present in a mixture of CH4 and C2H6 in a 2.50-L vessel at 25°C and 1.76 atm, given that the partial pressure of CH4 is 0.53 atm.

What is the number of moles of CH₄?

What is the number of moles of C₂H₆?

Answer 1

Total pressure of mixture (CH4 and C2H6) = 1.76atm

The parital pressure of CH4                         = 0.53atm

The parital pressure of C2H6                        = total pressure of mixture - partial pressure of CH4

                                                                     = 1.76-0.53    = 1.23atm

for CH4

PV = nRT

PCH4 = 0.53atm

     T    = 25+273 = 298K

   V    = 2.5L

n = PV/RT

      = 0.53*2.5/0.0821*298    = 0.054 moles of CH4 >>>>>answer

for C2H6

PV = nRT

PC2H6 = 1.23atm

     T    = 25+273 = 298K

   V    = 2.5L

n = PV/RT

      = 1.23*2.5/0.0821*298    = 0.126 moles of C2H6 >>>>>answer