Question

In the copper – silver nitrate lab Copper medals and silver nitrate solution reacted to produce silver metal and copper (II) nitrate in solution. A student placed a copper wire with a mass of 2.93 g in the reaction test tube. The silver nitrate solution contained 1.41 g of silver nitrate. He obtained .87 g of silver metal. Calculate the percent yield of silver.

Answer 1

Answer:

Percent Yield = 97.75 %

Explanation:

1 MOLE = It is equal to the molar mass of the substance

1 mole of Cu = 63.54 g (Molar Mass of Cu = 63.54 g/mole)

1 mole of AgNO3 = 170 g (Molar Mass of AgNO3 = 170 g/mol)

Given Mass of AgNO3 = 1.41 g

Given Mass of Cu = 2.93 g

Second step : Find the limiting Reagent (which is in less amount)

Balanced Chemical equation :

$Cu + 2AgNO_{3} \rightarrow Cu(NO_{3})_{2}+2Ag$

This means

1 mole of Cu will react with  = 2 mole of AgNO3

63.54 g of Cu  reacts with = 2 x 170 g of AgNO3

1 g  of Cu  reacts with = (2 x 170)/63.54 of AgNO3

$= \frac{170\times 2}{63.54}$

= 5.35 g of AgNO3

2.93 g should reacts with = 2.93 x 5.35 = 15.67 g of AgNO3

Available AgNO3 = 1.41 g

So , AgNO3 is less than required = limiting reagent

Now the reaction occur 1.41 g of AgNO3

Now, Limiting reagent will decide How much Silver(Ag) Metal will form

2 mole of AgNO3 will produce = 2 mole of Ag

1 mole of AgNO3 will produce = 1 mole of Ag

170 g  AgNO3 will produce = 107.86 mole of Ag(Molar mass of Ag = 107.86)

1 g AgNO3 will produce =

$\frac{107.86}{170}$

1.41 g of AgNO3 will produce =

$\frac{107.86\times 1.41}{170}$

= 0.89 g

$Yield\ Percent = \frac{Actual\ Yield}{Theoritical\ Yield}\times 100$

Actual yield = 0.87 g

Theoritical yield = 0.89 g

$Yield\ Percent = \frac{0.87}{0.89}\times 100$

Percent Yield = 97.75 %