How many moles of Ag will be produced from 16g of Cu, assuming AgNO3 is available in excess

Assuming the reaction you are referring to is the following:

AgNO3 + Cu - -> Cu (NO3) 2 + Ag

First, we should balance the reaction:

2 AgNO3 + Cu - -> Cu (NO3) 2 + 2 Ag

Now we carry out dimensional analysis, taking into account the molar ratios of different species as given in the balanced reaction and molar masses (which we can look up in the periodic table).

We begin with what we know, which is that we have 16.0 g Cu reacting and work our way toward the quantity that we would like to calculate, namely moles of Ag.

16.0 g Cu x 1 mol Cu x 2 mol Ag = 0.504 mol Ag

63.5 g Cu 1 mol Cu