Answer:
Step-by-step explanation:
The essential though process is to ask oneself when converting grams to moles=> 'How many formula weights are in the given mass?' This directs one to divide the substance's formula weight into the given mass (in grams) on order to determine number of moles. That is ...
moles = Given Mass of Substance in grams / formula weight of substance in grams
= 1578 grams / 791 grams-mol.⁻¹ =1.995 mole ≅ 2 moles