Question

a piece of zn metal is added to an agno₃ solution, resulting in the plating of silver onto the piece of metal. this reaction is spontaneous.
what describes this reaction?
the reaction is an electrolytic cell.
the reaction is a downs cell.
the reaction is not a redox reaction.
the reaction is a single replacement reaction.

Explanation:

1. Analyze each option:

• Option 1: Electrolytic cells require external energy (like a battery) to drive non - spontaneous reactions. The given reaction is spontaneous, so it's not an electrolytic cell.
• Option 2: A Downs cell is used for the electrolysis of molten sodium chloride to produce sodium and chlorine. This reaction has nothing to do with a Downs cell.
• Option 3: In the reaction between Zn and \(AgNO_3\), Zn is oxidized (loses electrons) and \(Ag^+\) is reduced (gains electrons), so it is a redox reaction.
• Option 4: The reaction is \(Zn(s)+2AgNO_3(aq)=Zn(NO_3)_2(aq) + 2Ag(s)\). In this reaction, Zn replaces Ag in \(AgNO_3\), which fits the pattern of a single - replacement reaction (A + BC = AC + B, where A is Zn, B is Ag, and BC is \(AgNO_3\)).

Answer:

The reaction is a single replacement reaction.