Step-by-step explanation:
Every mole of Ag2 O has TWO moles of Ag in it .
Find number of moles of Ag2 O in 29.9 grams
Mole weight of Ag2 O 2 X 107.87 + 15.999 = 231.739 gm / mole
29.9 gm / 231.739 gm / mole = .129 moles of Ag2 O
Remember there are TWICE as many moles of Ag = .258 moles