1. Determine the molar mass of C2H4:

* Carbon (C) has a molar mass of 12.01 g/mol

* Hydrogen (H) has a molar mass of 1.01 g/mol

* Molar mass of C2H4 = (2 * 12.01 g/mol) + (4 * 1.01 g/mol) = 28.05 g/mol

2. Determine the moles of carbon in 450 moles of C2H4:

* Each mole of C2H4 contains 2 moles of carbon.

* Moles of carbon = 450 moles C2H4 * (2 moles C / 1 mole C2H4) = 900 moles C

3. Calculate the mass of carbon:

* Mass of carbon = moles of carbon * molar mass of carbon

* Mass of carbon = 900 moles C * 12.01 g/mol = 10809 g

Therefore, there are approximately 10809 grams of carbon in 450 moles of C2H4.