Using the reaction ...?

Question

Cu+2AgNO3 - Cu(NO3)2 + 2 Ag calculate the mass of copper necessary to form the mass of silver that you obtained.

Answer 1

I do not know what mass of Ag you obtained . But to generalize this equation

1 mole of Cu(0) = 63.55 grams  will react with 2 moles of AgNO3 ( 338 grams ) to produce 2 moles of Ag (0){ 215.8 grams }     so if 63.55 grams of Cu will result in 215.8 grams of Ag then if you react 10 grams of Cu the theoretical yield of Ag will be

63.55/215.8 = 10/X =    { (215.8)(10)}/63.55 = 33.96 grams

if you obtained only 27 grams of Ag instead of the theoretical 33.96 then your percent yield is  

actual grams/theoretical grams X 100 = 27/33.96 x 100 = 79.5% . Now use your actual yield that you obtained and set uo the equation as given above..