The quantity "one mole" will not be equal to

a. 22.4 L of H₂ (g) at STP

b. 6.02 x 10²³ carbon atoms

c. 64 grams of SO₂ (g)

d. 36 grams of H₂O

e. 207 grams of Pb

1 mole can be written many different ways. Converting a mole to atoms would require you to multiply the number of moles by (6*10^23), so b is out. Converting moles to Liters would require multiplying the number of moles by 22.4, so a is out. Converting moles to grams would require multiplying the number of moles by the molar mass of the element/compound. The molar mass of Pb (Lead) is 207, so e is out. The molar mass of SO2 is 32 + 32 = 64, so c is out. That only leaves d. In order to prove this, take the molar mass of H2O (which is 16 + 1 + 1 = 18) and multiply it by 1. The number you get from this is 18, which is not 36, so your final answer is D.