Answer to Question #314112 in General Chemistry for maddie

Question

How many grams of Cu would have to react to produce 89.5 grams of Ag

Answer 1

The reaction is:

$Cu + 2Ag(+)=>Cu(2+) +2Ag$

According to the equation, 0.5 mol (or 1 mol) of Cu would have to react to produce 1 mol of Ag (or 2 mol):

$\nu(Cu)=1/2\cdot\nu(Ag)$

$M(Cu)=63.5 g/mol$

$M(Ag)=107.9 g/mol$

89.5 g of Ag is:

$\nu(Ag)=m(Ag)/M(Ag)=89.5 g/(108g/mol)=0.83mol$

$$\nu=m/M=>m=\nu\cdot M$$

Then m(Cu):

$m(Cu)=\nu(Cu)\cdot M(Cu)=1/2\cdot\nu(Ag)\cdot M(Cu)=$ $=0.5\cdot 0.83mol\cdot 63.5g/mol=26.3g$