Question

calcula el peso molecular de un gas contenido en un volumen d 138.2 ml a una presion de 700 torr , una temperatura d 100ºc y una masa d 0.4283g .

Answer 1

Ley de los gases ideales

P · V  = n · R · T    (a)

R = 0.082 ( L mol/mol K)

T = 100 ºC+ 273 = 373 K

m = 0.4283 g

P = 700 / 760 = 0.921 atm

V = 138.2 / 1000 = 0.1382 L

calcular Mm

Mm  =  m  ·  R  · T
          ````````````````
               P ·  V

Mm =  0.4283 g · 0.082 ( L atm/mol K) · 373 K
          ````````````````````````````````````````````````````````
                       0.921 atm  ·  0.1382 L

Mm = 102.92 g/mol

n (moles) = masa/Mm (b)

sustituir en la ecuación (a)

P · V =  m ·  R  ·  T
            ````
            Mm