3. If 12.5 grams of copper are reacted with excess chlorine gas, then 25.4 grams of copper (II) chloride are produced. Calculate the theoretical yield and the percent
yield. Cu + Cl2 → CuCl2

Percent yield = 99.6%

Theoretical yield = 25.5 g

Explanation:

Given data:

Mass of copper = 12.5 g

Mass of copper(II) chloride produced = 25.4 g

Theoretical yield = ?

Percent yield = ?

Solution:

Chemical equation:

Cu + Cl₂       →        CuCl₂

Number of moles of copper:

Number of moles = mass/molar mass

Number of moles = 12.5 g / 63.5 g/mol

Number of moles = 0.19 mol

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

                  Cu          :           CuCl₂

                     1           :               1

                  0.19        :           0.19

Mass of CuCl₂: Theoretical yield

Mass = number of moles × molar mass

Mass = 0.19 mol × 134.45 g/mol

Mass = 25.5 g

Percent yield:

Percent yield = (actual yield / theoretical yield )×100

Percent yield  = ( 25.4 g/ 25.5 g) ×100

Percent yield = 99.6%

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