Answer:
130.76g of Zn are needed
Step-by-step explanation:
Zinc, Zn, reacts with silver nitrate, AgNO3, as follows:
Zn + 2AgNO3 → Zn(NO3)2 + 2Ag
Where 1 mole of Zn reacts with 2 moles of AgNO3
For a complete reaction of 4 moles of AgNO3 are needed:
4mol AgNO3 * (1mol Zn / 2mol AgNO3) = 2mol Zn
The mass of Zn is (Molar mass: 65.38g/mol):
2mol Zn * (65.38g / mol) =
130.76g of Zn are needed