Question

How many atoms of hydrogen are there in 3.0kg of ethane?

Answer 1

[relative atomic mass: H=1, C=12; Avogadro constant = 6.0 x 10^23 per mol]

Answer 2

first find the moles of ethane in that mass.

then multiply the moles by the number of H atoms in the compound.

THEN, finally, multiply that number by avogadros number