If portion of the unknown were to be placed in a blue Bunsen flame, a green-blue flame would appear. This indicates the presence of copper. If a portion of the unknown were to be added to dilute hydrochloric acid, bubbling would occur and upon passing the gas into limewater, the limewater would turn milky. This indicates the presence of a carbonate. Addition of dilute sodium hydroxide solution to the copper chloride solution formed earlier would cause a light blue precipitate to form, which is a confirmatory test for copper. Further confirmation can be achieved by adding concentrated ammonia solution to the light blue precipitate, which would then dissolve giving way to a dark royal blue solution of tetramminocopper(II).