Question

The balanced chemical equation for the reaction of copper (Cu) and silver nitrate (AgNO3) is shown below.

Cu + 2AgNO3 mc001-1.jpg 2Ag + Cu(NO3)2


How many moles of copper must react to form 3.50 mol of Ag?


0.175 mol

1.75 mol

7.00 mol

17.0 mol

Answer 1

Answer : The correct option is, 1.75 mol

Solution : Given,

Moles of silver = 3.50 mole'

The balanced chemical reaction is,

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

From the balanced chemical reaction, we conclude that

As, 2 moles of silver obtained from 1 mole of copper

So, 3.50 moles of silver obtained from
`(3.50)/(2)=1.75` moles of copper

Therefore, the 1.75 number of moles of copper must react to form 3.50 mole of silver.

Answer 2

Cu + 2 AgNO₃ = 2 Ag + Cu(NO₃)₂

mole ratio:

1 mole Cu --------------> 2 moles Ag
? mole Cu --------------> 3.50 moles Ag

moles Cu = 3.50 x 1 / 2

moles Cu = 3.50 / 2

= 1.75 moles

Answer B

hope this helps!