Question

Calculate the molar mass of a gas at 388 torr and 45°c if 206 ng of gas occupies 0.206 ul. (

Answer 1

To make our solution more systematic, let's convert all units that is consistent with the units of R which is 0.0821 L-atm/mol-K.

For pressure: 760 torr = 1 atm
388 torr * 1 atm/760 torr = 0.5105 atm

For volume, 1 μL = 10⁻⁶ L
0.206 μL * 10⁻⁶ L/1 μL = 2.06×10⁻⁷ L

For temperature,
T = 45 + 273 = 318 K

For mass, 1 ng = 10⁻⁹ g
206 ng * 10⁻⁹ g/1 ng = 2.06×10⁻⁷ g

Assuming ideal gas,

PV=nRT
(0.5105 atm)(2.06×10⁻⁷ L) = n(0.0821 L-atm/mol-K)(318 K)
n = 4×10⁻⁹ mol

Molar mass = Mass/n = 2.06×10⁻⁷ g/4×10⁻⁹ mol
Molar mass = 51.14 g/mol

Answer 2

The molar mass of a gas is 51.14g/mol.

Given Here,

Temperature - 318 K

Pressure - 0.51atm

Volume -  $\bold{2.06\times 10^-^7 L}$

Mass - $\bold{2.06\times 10^-^7g}$

Assuming STP,

PV = nRT

$\bold {(0.51atm ) (2.06\times 10^-^7) = n (0.0821) (318K)}\\\\\bold {n = 4\times 10^-^9}$

$\rm \bold{Molar Mass = \frac{Given Mass }{n}} \\\rm \bold{MolarMass = 2.06\times\frac{ 10^-^7g}{4\times10^-^9 mol} }\\\\\rm \bold{MolarMass = 51.14g/mol}$

So, we can conclude that the molar mass of a gas is 51.14g/mol.

To know more about molar mass, refer the link:

https://brainly.com/question/22994596?referrer=searchResults