Question

Explain why, in the balanced equation C+O2 yields CO2 we know that 1g of C will NOT react exactly with 1g of O2.

Answer 1

Chemical reactions occur in terms of molecules/atoms, when we perform stoichiometric calculations we use a shortcut - moles (which is a specific number of molecules/atoms, \(6.022*10^{23}\)). We can't use mass in these calculations because the masses of different atoms/molecules are not equivalent. e.g. the number of atoms in 1 g of carbon is not the same as the number of molecules in 1 g of \(O_2\).