“Silver tree” experiment

How to turn a copper tree into a silver one

In this beau­ti­ful ex­per­i­ment, we’ll show you how to make nee­dle-like sil­ver crys­tals us­ing cop­per.

Safe­ty pre­cau­tions

Wear pro­tec­tive gloves and glass­es. The re­ac­tive mix­ture must not be poured down the sink or into wa­ter tanks.

Reagents and equip­ment:

  • cop­per tree;
  • sil­ver ni­trate so­lu­tion 5 g/l;
  • beaker.

Step-by-step in­struc­tions

Put the cop­per tree in the beaker. Then pour the sil­ver ni­trate so­lu­tion over it. Ob­serve the sil­ver crys­tals set­tle on the sur­face of the tree.

Pro­cess­es de­scrip­tion

In the re­ac­tiv­i­ty se­ries of met­als, cop­per is to the left of sil­ver, so it can force sil­ver out of so­lu­tions of sil­ver salts. Shiny nee­dle-like sil­ver crys­tals ap­pear on the sur­face, and the so­lu­tion turns a blue col­or, as the cop­per ions move into the so­lu­tion. The col­or is un­even, as the lay­er of sil­ver is not durable and breaks off, thus “re­veal­ing” the cop­per. The cop­per re­acts in­creas­ing­ly with the sil­ver ni­trate so­lu­tion, and the con­cen­tra­tion of cop­per ions in these ar­eas in­creas­es, which means that the col­or­ing of the lay­er in­ten­si­fies

Cu + Ag­NO₃ = Ag + Cu(NO₃)₂