Please help. What mass of copper is required to replace silver from 4.00g of silver nitrate dissolved in water? I found the molar mass of all of them but don't know where to go from there

Answer:
0.7479 grams of copper is required to replace 4.00 grams of silver nitrate.
Explanation:
[tex]Cu+2AgNO_3\rightarrow Cu(NO_3)_2+2Ag[/tex]
Moles of silver nitrate = [tex]\frac{4.00 g}{169.87 g/mol}=0.0235 mol[/tex]
According to reaction 2 moles of silver nitrate reacts with 1 mole of copper metal.
Then 0.02354 moles of silver nitrate will react with:
[tex]\frac{1}{2}\times 0.0235 mol=0.01177 mol[/tex]
Mass of 0.01177 moles copper =0.01177 mol × 63.55 g/mol = 0.7479 g
0.7479 grams of copper is required to replace 4.00 grams of silver nitrate.