Question

A sample of an ideal gas occupies a volume of 25.0 liters at a pressure of 1.20 atm and a temperature of 75 degrees C. How many moles of gas are present in the container?

Answer 1

ANSWER : For an ideal gas we know that PV = nRT

since an ideal gas is one which obeys both Charles law and Boyles law , hence for an ideal gas we have the ideal gas equation PV = nRT where P = pressure of the gas , here P = 1.20 atm ;

                                                  V = volume of the gas , here volume = 25.0 ltrs

                                                  n = number of moles, here we need to calculate it .

                                                 R = constant = universal gas constant = 8.314 J/K/mol

                                                 T = absolute temperature, here T = 75⁰C = (75 + 273 )K = 348 K

   From the above equation we get n = (P x V) / (R x T) moles ==> n = ( 1.20 x 25 ) / ( 8.314 x 348)

                                                         n = 30 / 2893.272 = 0.0103 moles

          The no. of moles gas present in the container = 0.0103 moles