Using the ideal gas equation PV = NRT (N is number of moles) P0V0=NiR×290 .....(1) [Ti=273+17=290K] After heating P0V0=NfR×300 .....(2) [Tf=273+27=300K] from equation (1) and (2) Nf−Ni=
P0V0
R×300
−
P0V0
R×290
difference in number of moles −
P0V0
R
[
10
290×300
] Hence nf−ni is =
P0V0
R
×[
10
290×300
]×6.023×1023 puttingP0=105PA and V0−30m3 Number of molecules nf−ni=−2.5×1025