A mixture of ethane and ethene occupies 41 L at 1 atm and 500 K. The mixture reacts completely with 10.3 mole of O2 to produce CO2 and H2O. The mole fractions of ethane and ethene in the mixture are (R = 0.082 L atm K–1mol–1) respectively
0.50, 0.50
0.75, 0.25
0.67, 0.33
0.25, 0.75