From 200mg of CO₂, 10²¹ molecules are removed. How many moles of CO₂ are left?

To determine how many moles of CO₂ are left after removing a certain number of molecules, we first need to calculate the initial number of moles in 200 mg of CO₂.

Step 1: Calculate Initial Moles of CO₂

The molar mass of CO₂ is approximately 44 g/mol. To convert 200 mg to grams:

• 200 mg = 0.2 g

Now, we can find the number of moles:

• Number of moles = mass (g) / molar mass (g/mol)
• Number of moles = 0.2 g / 44 g/mol ≈ 0.004545 moles

Step 2: Calculate Number of Molecules Removed

Using Avogadro's number, which is approximately 6.022 x 10²³ molecules/mol, we can find out how many moles correspond to 10²¹ molecules:

• Number of moles removed = number of molecules / Avogadro's number
• Number of moles removed = 10²¹ molecules / 6.022 x 10²³ molecules/mol ≈ 0.000166 moles

Step 3: Calculate Remaining Moles of CO₂

Now, subtract the moles removed from the initial moles:

• Remaining moles = initial moles - moles removed
• Remaining moles = 0.004545 moles - 0.000166 moles ≈ 0.004379 moles

Final Result

After removing 10²¹ molecules, approximately 0.004379 moles of CO₂ are left.