Question

The balanced chemical equation for the reaction of copper (Cu) and silver nitrate (AgNO3) is shown below.
Cu + 2AgNO3 es002-1.jpg 2Ag + Cu(NO3)2
How many moles of AgNO3 must react to form 0.854 mol Ag?

Answer 1

Remark
The balance numbers in front of Ag and AgNO3 are both 2. That number is in moles.

Rule: if the moles are the same in the equation, then whatever you are given for one, will be the same for the other. So you have 0.854 moles of Ag. You will also have 0.854 moles of AgNO3 

Answer: 0.854 <<<<<

Answer 2

Answer: Moles of $AgNO_3$ that must be reacted are 0.854 moles.

Explanation:

For the given chemical reaction, the equation follows:

$Cu+2AgNO_3\rightarrow 2Ag+Cu(NO_3)_2$

By Stoichiometry of the reaction:

2 moles of silver are produced when 2 moles of silver nitrate is reacted.

So, 0.854 moles of silver is formed when = $\frac{2}{2}\times 0.854=0.854moles$ of silver nitrate is reacted.

Thus, moles of $AgNO_3$ that must be reacted are 0.854 moles.