Answer:
146 grams Mg
Explanation:
Mg + 2AgNO3 -> 2Ag + Mg(NO3)2
The balanced equation tells us we need 1 mole of Mg for every 2 moles of silver nitrate.
Since we have 3.00 moles of AgNO3, we'll need 2x that, or 6 moles of Mg.
The molar mass of Mg is 24.3 grams/mole
(6 moles Mg)(24.3 grams Mg/mole Mg) = 145.8 grams Mg. 146 grams with 3 sig figs.
