The density of a certain mass of a gas at `STP` is `d`. If the pressure of the gas is doubled and the temperature is made one-third of its initial value, the new density will be

Options

A. `3 d`
B. `4.5 d`
C. `6 d`
D. `9 d`

Answer

C

Explanation

`PV = nRT = (M)/(M_(0))RT`
`P = (M)/(V)(RT)/(M_(0)) = d(RT)/(M_(0))`
`2P = d' = (R(T//3))/(M_(0))`
`2d (RT)/(M_(0)) = (d' R(T//3))/(M_(0))`
`d' = 6d`