A closed vessel with rigid walls contains 1 mole of `._(92)^(238)U` and 1 mole of air at `298K`. Considering complete decay of `._(92)^(238)U` to `._(82)^(206)Pb`the ratio of the final pressure to the initial pressure of the system at `298K` is

Answer

9

Explanation

In conservation of `._(92)^(238)U` to `._(82)^(206)Pb, 8alpha`-particles and `6beta` particles are ejected.
The number of gaseous moles intially `=1` mole
The number of gaseous moles finally `=1+8` moles (1 mole from air and 8 mole of `._(2)He^(4)`)
So the ratio `=9//1=9`