Question

17) A gas mixture contains 2.00 moles of hydrogen, 4.25 moles of carbon dioxide, and 3.75 moles of nitrogen in a 200. L flask. If the total pressure in the flask is 100.0 torr, what is the partial pressure of carbon dioxide? 288a-4

Answer 1

Given,

number of moles of hydrogen = 2 mol

number of moles of nitrogen = 3.75 mol

number of moles of carbon dioxide = 4.25 mol

total pressure = 100 torr

volume= 200L

By Dalton's law of partial pressure,relationship between partial pressure and mole fraction is given as-

P_i =n_i x P

where,

P_i = partial pressure of gas

n_i = mole fraction of that gas = (number of moles of that gas/total number of moles of gas present in mixture)

P = total pressure

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

n_co2 = 4.25/(2+4.25+3.75)

n_co2 = 0.425

Now partial pressure of CO₂=

P_CO2 = n_CO2 x P

P_CO2 = 0.425 x 100

P_CO2 = 42.5 torr