Synthetic Inorganic Chemistry

CUPROUS CHLORIDE 223

insoluble CuCl only in proportion to its first power. Therefore

reaction (3) runs to the left and reaction (2) to the right and white

CuCl precipitates.

In the following procedure finely spun copper is placed in a

solution of CuCl 2 and concentrated HCl and warmed. The clear

solution of the complex is poured into a large volume of water,

and the precipitate of CuCl is collected, washed, and dried with

great precaution to avoid oxidation.

In the presence of dilute HCl cuprous chloride is slowly oxidized

by air to soluble cupric salt which can be washed off.

2CuCl + 2HC1 + §O 2 -»• H 2 O + 2CuCl 2

Without HCl the dark-colored insoluble basic salt is produced to

contaminate the preparation

2CuCl + H 2 O + \O 2 -» 2Cu(0H)Cl |

Thoroughly dry cuprous chloride is not oxidized by the air.

Materials: cupric chloride, CuCl 2 -2H 2 0,43 grams = 0.25 F.W.

fine copper ribbon, 25 grams (the material used for

domestic scouring pads).

122V HCl, 100 cc.

95% alcohol, 30 cc

ether, 80 cc.

Apparatus: 500-cc. flask.

short-stemmed funnel.

2-liter common bottle,

suction filter and trap bottle,

iron ring and ring stand.

Bunsen burner.

Procedure: Dissolve 43 grams of crystallized cupric chloride
in 100 cc. of water, and filter the solution into a 500-cc. flask.
Rinse the filter with 10 cc. of water. Add 100 cc. of 122V HCl
and then 25 grams of fine copper ribbon. Note the color changes
which take place. Suspend a short-stemmed funnel in the neck
of the flask to prevent the loss of acid and to exclude air. Heat
the mixture with a low flame until it just reaches the boiling
point. Then reduce the flame to the smallest possible size and
keep the solution just below the boiling point until the color