At the top of a mountain a thermometer reads 7∘ and barometer reads 70 cm of Hg. At the bottom of the mountain they read 27∘ and 76 cm of Hg respectively. Compare the density of the air at the top with that at the bottom.
The correct option is A 0.9868
According to gas equation PV = nRT
PV=mMRT[as n=mM]or PρT=MR[as mV=ρ]
Now as M and R are same for top and bottom
(PρT)T=(PρT)Bi.e. ρTρB=PTPB×TBTTSo ρTρB=7076×300280=7576=0.9868