1. CO2 in solid form is called dry ice. You have a block of dry ice that weighs 500g. How many moles of CO2 molecules do you have?

Answer 1

moles = grams/molar mass.

Answer 2

thanks Dr Bob, Here is what i have come up with:
44.0095g/mole (Mass)
500/44.0095=11.36118338085

maybe I am correct?