Here's how to calculate the grams in 12 moles of CO2:

1. Find the molar mass of CO2:

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

* Oxygen (O) has a molar mass of 16.00 g/mol

* CO2 has one carbon atom and two oxygen atoms, so its molar mass is: 12.01 g/mol + (2 * 16.00 g/mol) = 44.01 g/mol

2. Multiply the moles by the molar mass:

* 12 moles CO2 * 44.01 g/mol CO2 = 528.12 grams

Therefore, there are 528.12 grams in 12 moles of CO2.