... using eqns. (11 .1) , (11 .4), and (11 .6) and (11 .5), (11 .4), and (11 .2), respectively, M may be written in terms ofeither mole or mass fractionM =ixiMior 1 M=imiMi (11 .8)Mole fraction ... pressures, 1 p =ipi (11 .15 )Finally, we combine eqns. (11 .6), (11 .13 ), and (11 .15 ) to obtain a veryuseful relationship between xi and pi:xi=cic=picR◦T=pip (11 .16 )in which ... as:pi= ρiRiT (11 .11 )In eqn. (11 .11 ), Riis the ideal gas constant for species i:Ri≡R◦Mi (11 .12 )where R◦is the universal gas constant, 8 314 .472 J/kmol·K. Equation (11 .11 )may alternatively...