Question

63.55 169.88 187.57 107.87

Answer 1

Answer:

1.2 g

Explanation:

Data Given:

mass of Ag = 3.98 g

mass of Cu = ?

Reaction Given:

               Cu + 2AgNO₃ --------→ Cu(NO₃)₂ + 2Ag

Solution:

To solve this problem we have to look at the reaction

Reaction:

                   Cu + 2AgNO₃ --------→ Cu(NO₃)₂ + 2Ag

                1 mol                                                 2 mol

from reaction we come to know that 1 mole of Cu give 2 moles of Ag

Now Convert moles to mass

Molar mass of Cu = 63.5 g/mol

Molar mass of Ag = 107.9 g/mol

So,

            Cu         +        2 AgNO₃ --------→     Cu(NO₃)₂   +   2Ag

         1 mol (63.5 g/mol)                                                    2 mol ( 107.9g/mol)

           63.5 g                                                                       215.8 g

So if we look at the reaction 63.5 g of Cu gives 215.8 g of Ag, then how many g of Cu will be Produce by 3.98 g of Ag

For this apply unity formula

                 63.5 g of Cu  ≅ 215.8 g of Ag

                  X g of Cu  ≅ 3.98 g of Ag

By Doing cross multiplication

                 mass of Cu = 3.98 g x 63.6 g / 215 g

                 mass of Cu =  1.2 g

1.2 g of Cu will produce 3.98 g of Ag