How may moles of oxygen are present in `400 cm^(3)` sample of the gas at a pressure of 760 mm of Hg at a temperature of 310K. (The value of R 1 s 8.31 kP a `dm^(-3) K^(-1) "mol"^(-1))`

Explanation

Here value of R is given in SI unit : pressure and volume is expressed in Kpa and `dm^(3)` .
Thus `P=760 mm 101*3 kPa, v=400 cm^(3) =400xx10^(-3) dm^(3)` According to ideal gas equation.
`pv=nRT`
`n=(pv)/(RT)=(101*3xx0*40)/(8*31xx310)=0*01572`
`:. n=1 1*57xx10^(-2) "mol"`