How many molecules of CO2 are there in 3.55 g of CO2?

4.9∗1022  molecules of CO2 in a 3.6 gram sample.

Explanation:

The gram molecular weight of co2 is 44 gms.

So the number of molecules in 44 gms of co2 is 6.023×10^23 .

Then the number of molecules in 3.6 gms of co2 is (6.023×10^23×3.6)÷44 = 4.92×10^22

i think it's letter a.