Copper: reactions of elements
Reaction of copper with air
Copper metal is stable in air under normal conditions. At read heat, copper metal and oxygen react to form Cu2O.
4Cu(s) + O2(g) → 2Cu2O(s)
Reaction of copper with water
Reaction of copper with the halogens
The reaction between copper metal and the halogens fluorine, F2, chlorine, Cl2, or bromine, Br2, affords the corresponding dihalides copper(II) fluoride, CuF2, copper(II) chloride, CuCl2, or copper(II) bromide, CuBr2 respectively.
Cu(s) + F2(g) → CuF2(s) [white]
Cu(s) + Cl2(g) → CuCl2(s) [yellow-brown]
Cu(s) + Br2(g) → CuBr2(s) [black]
Reaction of copper with acids
Copper metal dissolves in hot concentrated sulphuric acid to form solutions containing the aquated Cu(II) ion together with hydrogen gas, H2. In practice, the Cu(II) is present as the complex ion [Cu(OH2)6]2+.
Cu(s) + H2SO4(aq) → Cu2+(aq) + SO42-(aq) + H2(g)
Copper metal also dissolves in dilute or concentrated nitric acid, HNO3.