Answer:
2.27 moles (To 3s.f.)
Explanation:
The formula to find moles using mass requires you to have the Mr (Relative molecular mass) of the compound. Luckily, this is easily checked from the periodic table.
According to the periodic table, carbon has a relative atomic mass of 12 and oxygen has a relative atomic mass of 16. So, the Mr of CO2 is 12 + 16 + 16 = 44
Accorsing to the formula, moles = Mass/Mr so
Moles = 100/44
= 2.27272727
= 2.27 (To 3s.f.)
