4. Two flasks A and B of 1 L capacity each contains SO2 and Br2 gases respectively maintained at 340 K and pressure of 1.5 atmosphere. If number of Br2 molecules in flask B is N, the total number of atoms in flask A will be

SO2 and Br2 are under same conditions  ∴ PV = nRT no.of moles of each gas n =PVRT=1.5×10.0821×340=0.054 no. of molecules=no.of moles×N no.of molecules of Br2=N   ∴no. of moles of Br2=1 no.of atoms=Atomicity×no.of molecules no.of atoms  of in SO2=3N