For the following reaction 563 grams of carbon tetrachloride
For the following reaction, 5.63 grams of carbon tetrachloride are mixed with excess methane (CH4) . The reaction yields 5.09 grams of dichloromethane (CH2Cl2) .
 methane (CH4) ( g ) + carbon tetrachloride ( g )----->dichloromethane (CH2Cl2) ( g )
Solution
The balanced equation is
CH4 + CCl4 ----> 2 CH2Cl2
Number of moles of CCl4 = 5.63 g / 153.82 g/mol = 0.0366 mole
from the balanced equation we can say that
1 mole of CCl4 produces 2 mole of CH2Cl2 so
0.0366 mole of CCl4 will produce
= 0.0366 mole of CCl4 *(2 mole of CH2Cl2 / 1 mole of CCl4 )
= 0.0732 mole of CH2Cl2
mass of 1 mole of CH2Cl2 = 84.93 g
so the mass of 0.0732 mole of CH2Cl2 = 6.22 g
Therefore, theoretical yield of CH2Cl2 = 6.22 g
percent yield = (actual yield / theoretical yield)*100
percent yield = (5.09 / 6.22)*100 = 81.8 %
Therefore, precent yield = 81.8

