Which one is heavier? 1mole of pbd4, 1mole of H2 and 1mole of pb(No3) 2

To determine which one is heavier, we need to know the molar masses of each compound. The molar masses are as follows:

1 mole of PbD4:
Molar mass of Pb: 207.2 g/mol
Molar mass of D: 2.014 g/mol (hydrogen deuteride)
Total molar mass of PbD4: (207.2 g/mol) + 4(2.014 g/mol) = 215.1 g/mol

1 mole of H2:
Molar mass of H: 1.008 g/mol
Total molar mass of H2: 2(1.008 g/mol) = 2.016 g/mol

1 mole of Pb(NO3)2:
Molar mass of Pb: 207.2 g/mol
Molar mass of N: 14.01 g/mol
Molar mass of O: 16.00 g/mol
Total molar mass of Pb(NO3)2: (207.2 g/mol) + 2(14.01 g/mol) + 6(16.00 g/mol) = 331.2 g/mol

Comparing the molar masses, we can see that 1 mole of Pb(NO3)2 is the heaviest at 331.2 g/mol, followed by 1 mole of PbD4 at 215.1 g/mol, and 1 mole of H2 being the lightest at 2.016 g/mol.