If 1021molecules are removed from 200mg of CO2, then the number of moles of CO2 left are

To answer this question, we need to follow these steps:

1. First, we need to find the number of moles in 200mg of CO2. The molar mass of CO2 is approximately 44.01 g/mol. So, we convert 200mg to grams which is 0.2g. Then, we divide the mass of the CO2 by its molar mass to find the number of moles.

   Number of moles = mass/molar mass = 0.2g / 44.01 g/mol = 0.00454 moles

2. Next, we need to find the number of molecules in 0.00454 moles of CO2. We use Avogadro's number (6.022 x 10^23 molecules/mole) for this calculation.

   Number of molecules = number of moles x Avogadro's number = 0.00454 moles x 6.022 x 10^23 molecules/mole = 2.73 x 10^21 molecules

3. Now, we subtract the 1021 molecules that were removed from the total number of molecules.

   Remaining molecules = total molecules - removed molecules = 2.73 x 10^21 molecules - 1021 molecules = 2.73 x 10^21 molecules (since 1021 molecules is negligible compared to 2.73 x 10^21 molecules)

4. Finally, we convert the number of remaining molecules back to moles using Avogadro's number.

   Remaining moles = remaining molecules / Avogadro's number = 2.73 x 10^21 molecules / 6.022 x 10^23 molecules/mole = 0.00454 moles

So, approximately 0.00454 moles of CO2 are left after removing 1021 molecules.