<u>Answer:</u> Moles of
that must be reacted are 0.854 moles.
<u>Explanation:</u>
For the given chemical reaction, the equation follows:

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 =
of silver nitrate is reacted.
Thus, moles of
that must be reacted are 0.854 moles.