Single replacement reaction for Copper and Zincate ions.- Not sure if I remember how to do correctly, did it acouple years ago.
According to one website, zincate ions form in basic solution: CHEMICAL PLATING OF A PENNY In this experiment, we will observe the plating of one metal with another by chemical means. We will plate zinc on the copper of a penny, which is just the opposite of what we normally would expect to happen. We know from our study of ions that the Zn++ ion combines with two OH- ions to form zinc hydroxide Zn(OH)2. However, in the presence of sodium hydroxide NaOH, zinc will combine to form the complex ion known as a zincate ion. [Zn(OH)4] - - or [Zn(OH)3 * H2O] - it is this zincate ion which allows zinc to plate on copper. Another website that provides a lab procedure for zinc plating pennies explains the formation of zincate ions in the following way: In this reaction, zinc dissolves in the hot concentrated sodium hydroxide solution to form sodium zincate, commonly written as Na2ZnO2, or, as obtained in solid form from concentrated solutions, NaZn(OH)3. As an ionic equation this can be written: Zn + 2 OH- --> ZnO22- + H2 None of these websites mention single replacement reactions for copper and zincate ions.
