Question

How many moles of silver nitrate (AgNO3) are needed to produce 6.75 moles of copper (ll) nitrate (Cu(NO3)2) upon reacting with excess copper (Cu)

Answer 1

13.5 moles of AgNO₃

Step-by-step explanation:

To determine the reaction:

Reactants: AgNO₃ and Cu

Products: Cu(NO₃)₂ and Ag

2 moles of AgNO₃ react to 1 mol of Cu, in order to produce 1 mol of Cu(NO₃)₂ and 2 moles of solid silver.

2AgNO₃ + Cu → Cu(NO₃)₂ + 2Ag

Our production was 6.75 moles of Cu(NO₃)₂

Let's make the rule of three:

1 mol of Cu(NO₃)₂ is produced by 2 moles of AgNO₃

Then, our 6.75 moles were definetely produced by (6.75 . 2) /1 = 13.5 moles.

If the copper was in excess, then the silver nitrate is the limiting reactant:

2 mol of AgNO₃ can produce 1 mol of Cu(NO₃)₂

Then, 13.75 moles of silver nitrate must produce (13.5 . 1) /2 = 6.75 moles of Cu(NO₃)₂