An investigator carries out a series of displacement reactions to determine the relative reactivities of four metals: zinc, copper, tin, and an unknown metal Y.
She adds strips of tin to aqueous solutions of the nitrates of each of the four metals. After several minutes, she removes the tin strips and records her observations.
The first table displays her results:
| Solution | Result |
|---|---|
| zinc nitrate | no change |
| copper(II) nitrate | reddish-brown coating on tin |
| tin(II) nitrate | no change |
| nitrate of metal Y | grey coating on tin |
Name the substance that forms the reddish-brown coating on the tin in the copper(II) nitrate solution.
State why there is no visible change when tin is added to the tin(II) nitrate solution.
The investigator repeats the procedure using strips of the unknown metal Y instead of tin. The second table displays her results:
| Solution | Result |
|---|---|
| zinc nitrate | no change |
| copper(II) nitrate | reddish-brown coating on Y |
| tin(II) nitrate | no change |
| nitrate of metal Y | no change |
Using the evidence from both tables, arrange the four metals (zinc, copper, tin, and Y) in order of decreasing reactivity (from most reactive to least reactive).
Iron reacts with an aqueous solution of silver nitrate according to the following ionic equation:
Fe(s)+2Ag+(aq)→Fe2+(aq)+2Ag(s) \text{Fe(s)} + 2\text{Ag}^{+}(\text{aq}) \rightarrow \text{Fe}^{2+}(\text{aq}) + 2\text{Ag(s)} Fe(s)+2Ag+(aq)→Fe2+(aq)+2Ag(s)State why this reaction is classified as a redox reaction.
Identify, with reference to electron transfer, the species that acts as the oxidising agent in this reaction.
