Density of a gas is found to be `5.46//dm^(3)` at `27^(@)C` at 2 bar pressure What will be its density at `STP` ? .

Explanation

We know that
`pV=nRT`
`"or "p=(m)/(V)xx(RT)/(M)=(dRT)/(M)`
`therefore" "d=(pM)/(RT)`
`"or "d prop (p)/(T)" (R and M constant for a given gas)"`
`"or "(d_(1))/(d_(2))=(p_(1))/(p_(2))xx(T_(2))/(T_(1))`
`"or "d_(2)=(d_(1)xxp_(2)xxT_(1))/(p_(1)xxT_(2))`
`d_(1)="5.46 g dm"^(-2), p_(1)="2 bar"`
`T_(1)=273+27=300K`
`d_(2)=?" "p_(2)="1 bar "T_(2)=273K`
`therefore" "d_(2)=("5.46 g dm"^(-3)xx"1 bar"xx300K)/("2 bar"xx273K)`
`="3.0 g dm"^(-3)`