Copper (II) chloride, also known as CuCl2, is a deadly chemical that can affect your respiratory system, liver and your kidneys. It will corrode aluminum, is noncombustible and has no odour. Even so, it will create gas when burnt. It’s used as a wood preservative, dyeing, printing, and more. J.L Proust created the chemical in 1799 after Robert Boyle created Copper (I) Chloride (CuCl) in the seventeenth century. Normally, copper chloride is a very light brown, but when it goes in contact with water or alcohol, it will dissolve and turn into a blueish-green mixture. When placed above a fire, it will turn the flame into a green or a blue colour. Its melting point is 100°C and boiling point is 993°C.