Question

how to calculate number of molecules of 11 gram of co2

Answer 1

here 1 mole CO2 weigh 44 gms
i.e 44 gms =NA molecules
so 11 gms =NA/44×11 molecules =NA/4 molecules
here NA is avogadro number

Answer 2

moles = mass /molar mass
= 11 /44
= 0.25
molecules = moles × Avogadro's number
= 0.25. × 6.02 × 10 ^23
molecules = 1.505 × 10 ^ 23