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

In order to determine which substance is heavier, we need to compare their molar masses.

The molar mass of PbD4 (lead tetrahydride) can be calculated by summing up the atomic masses of each element in the compound:
- The molar mass of Pb is 207.2 g/mol
- The molar mass of D (deuterium) is 2.014 g/mol

Hence, the molar mass of PbD4 is (4 * 2.014) + 207.2 = 215.2 g/mol.

For H2 (hydrogen gas), the molar mass is simply the sum of two hydrogen atoms, which is 2 * 1.008 = 2.016 g/mol.

For Pb(NO3)2 (lead nitrate), we can calculate its molar mass:
- The molar mass of Pb is 207.2 g/mol
- The molar mass of N (nitrogen) is 14.007 g/mol
- The molar mass of O (oxygen) is 16.00 g/mol

So, the molar mass of Pb(NO3)2 is 207.2 + (2 * (14.007 + 3 * 16.00)) = 331.2 g/mol.

Comparing these molar masses, we see that:
- 1 mole of PbD4 weighs 215.2 grams
- 1 mole of H2 weighs 2.016 grams
- 1 mole of Pb(NO3)2 weighs 331.2 grams

Therefore, 1 mole of Pb(NO3)2 is the heaviest, while 1 mole of H2 is the lightest.