Question

Oxygen is present in a `1 L` flask at a pressure of `7.6xx10^(-10)mm Hg`. Calculate the number of oxygen molecules in the flask at `0^(@)C`.

Answer 1

Correct Answer - `2.7xx10^(10)gmol^(-1)`

Answer 2

 Correct answer is - \(2.7 \times 10^{10}\)

Using Ideal gas equation.

PV = nRT

\(n=\cfrac{\frac{7.6\times10^{-10}}{760}atm\times1L}{0.082\times273}\)

\(n=\frac{10^{-12}\times1}{22.386}\)

\(n=4.5\times10^{-12}\) mol.

\(\therefore\) Number of oxygen molecule \(=4.5\times10^{-12}\times6.022\times10^{23}\)

\(=27.099\times10^{11}\)

\(=2.7\times10^{10}.\)