Cupric chloride, also known as copper(II) chloride, is an inorganic compound with the chemical formula CuCl2. It is a yellow-green crystalline powder that is hygroscopic, which means it absorbs moisture from the air very easily. It consists of copper and chlorine atoms bonded together, with each copper atom bonded to two chlorine atoms in a linear geometry. Copper atoms have an oxidation state of +2 in this compound.

Physical and Chemical Properties

It is a solid at room temperature but melts at about 115°C to form a blue-green liquid. It readily sublimates, meaning it can change directly from the solid to gaseous states without going through a liquid phase in between. It is soluble in water, forming an acidic, blue-green colored solution. In solution, it exists as Cu2+ copper ions and Cl- chloride ions. It also dissolves in organic solvents like ethanol and acetone.

An interesting property of cupric chloride is that it acts as a Lewis acid. This means it readily accepts electron pairs from other atoms or molecules, forming coordination complexes. For example, when it is dissolved in water, it forms coordination complexes with water molecules, with water donating electron pairs to the central Cu2+ ion.

Chemical Reactions and Uses

One common use of Cupric Chloride is in qualitative inorganic analysis to test for the presence of ions like chloride, bromide and iodide. When its solutions are added to solutions containing these halide ions, characteristic colored precipitates are formed - white for chloride, orange for bromide and purple-black for iodide.

It is also used to prepare other copper compounds through substitution and oxidation-reduction reactions. For example, heating it with copper metal produces copper oxide:

CuCl2 + Cu → 2CuCl + CuO

It also acts as an oxidizing agent. Treating it with zinc metal produces copper metal and zinc chloride:

CuCl2 + Zn → Cu + ZnCl2

Some other applications of it include use as:

- Algicide in swimming pools - It prevents growth of algae.

- Mordant in textile dying - Helps dyes adhere firmly to fabrics like cotton.

- Catalyst in organic synthesis - Used to catalyze reactions like hydroboration, hydration etc.

- Wood preservative - Prevents fungus growth on wood.

Get more insights on - Cupric Chloride