Question

If 2 g of water contains z molecules, what will be number of molecules in 4 g of carbon dioxide?

Answer 1

2 g of water contains z molecules.
Hence 1 gm has z/2 molecules
1 mol(18 g) will have 9z molecules.



Now, for CO2,
Mass of CO2=44g
So number of moles=4/44=1/11 moles
Total number of molecules=(1*9z)/11
=9z/11