In a student experiment, the empirical formula of a copper halide was found by adding aluminum metal to an aqueous solution of the halide, displacing copper metal. the copper metal was filtered, washed with distilled water, dried, and weighed; three separate determinations were performed. the copper halide solution contained 42.62 g of copper chloride per liter. the student recorded the following experimental data. trial volume of copper chloride solution (ml) mass of filter paper (g) mass of filter paper with copper (g) a 49.6 0.908 1.694 b 48.3 0.922 1.693 c 42.2 0.919 1.588 part a write the empirical formula of copper chloride based on the experimental data.

The Empirical formula of copper chloride based on the experiment data is CuCl₃

In this case we first determine the mass of each atom in the compound from data given.

Mass of copper in Trial A = 1.694 - 0.908 = 0.786  

Mass of copper in Trial B = 1.693 - 0.922 = 0.771  

Mass of copper in Trial C = 1.588 - 0.919 = 0.669  

Average mass of copper = (0.786 + 0.771 + 0.669) ÷ 3  

                                         = 0.742 g of Copper

Volume in Trial A = 49.6 ml

Volume in Trial B = 48.3 ml

Volume in Trial C = 42.2 ml

Average volume of copper chloride = (49.6 + 48.3 + 42.2) ÷ 3

                                                            = 46.7 ml or  

                                                            = 0.046 L

But we are given 42.62 g of copper chloride in a liter, therefore;

Using proportions  

1 L = 42.62 g Copper chloride  

0.046 L will contain;  

= (42.62 g CuClₓ × 0.0467 L) ÷ 1

= 1.99 g Copper Chloride  

Mass of chlorine = Mass of copper chloride – mass of copper  

                           = 1.99 g – 0.742 g  

                          = 1.24 g chlorine  

Moles = mass / atomic mass  

Moles of copper = 0.742 g / 63.55 g/mol  

                          = 0.0117 moles copper  

Moles of Chlorine = 1.24 g/35.45 g/mol  

                             = 0.0350 moles Chlorine  

Copper: Chlorine

0.0117 moles : 0.0350 moles  

     = 1 : 2.98  

    = 1 : 3 (whole number ratio)

Therefore, the empirical formula of copper chloride is CuCl₃

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.