Answer to Question #281066 in General Chemistry for ggggg

Question

In a science laboratory, a group of scientists would like to test the reaction of argon and ethane (C2H6) vapor. A 2.00 L cylindrical container is filled with 3.50 g of argon at 60 ◦C. Ethane vapor is the added to the same container until the total pressure reached to 2.50 atm. Calculate the mass of ethane that was added in the container?

Answer 1

Molar mass of Argon= 39.948

Molar mass of Ethane= 30.0694

R= 0.08206 L atm/ mol K

60°C = 333K

Partial pressure of Argon:

PV =n RT

$n_{ar}=\frac{3.5}{39.948}= 0.08761\\P_{ar}= \frac{0.08761×0.08206×333}{2}\\=1.1970$

Partial pressure of Ethane

$2.5-1.1970\\=1.3030$

$\frac{n_{ar}}{n_{ethane}}=\frac{P_{Ar}}{P_{ethane}}$

$\frac{0.08761}{n_{ethane}}=\frac{1.1970}{1.3030}$

$n_{ethane}=0.09537$

Mass of ethane $=0.09537×30.0694\\$

$=2.868g$