12.5 g of copper are reacted with an excess of chlorine gas, and 25.4 g of copper(ii) chloride are
obtained. calculate the theoretical yield and the percent yield.

Percent yield = 94.5%

Theoretical yield =  26.89 g

Explanation:

Given data:

Mass of copper = 12.5 g

Mass of copper chloride produced = 25.4 g

Theoretical yield = ?

Percent yield = ?

Solution:

Cu + Cl₂  →  CuCl₂

Number of moles of Copper:

Number of moles = mass/ molar mass

Number of moles = 12.5 g/ 63.55 g/mol

Number of moles = 0.2 mol

Now we will compare the moles of copper with copper chloride.

          Cu          :           CuCl₂

           1             :              1

          0.2          :            0.2

Theoretical yield:

Mass of copper chloride:

Mass = Number of moles × molar mass

Mass = 0.2 mol × 134.45 g/mol

Mass = 26.89 g

Percent yield:

Percent yield = Actual yield / theoretical yield  × 100

Percent yield = 25.4 g/26.89 g × 100

Percent yield = 94.5%