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 a downs cell. the reaction is a single replacement reaction. the reaction is not a redox reaction. the reaction is an electrolytic cell.

Explanation:

1. Analyze "The reaction is a downs cell": Downs cell is for molten NaCl electrolysis, not this Zn - Ag reaction. Eliminate this.
2. Analyze "The reaction is a single replacement reaction": The reaction is \( \text{Zn}(s) + 2\text{AgNO}_3(aq)

ightarrow\text{Zn(NO}_3\text{)}_2(aq)+2\text{Ag}(s) \), where Zn replaces Ag in \( \text{AgNO}_3 \), fitting single - replacement (A + BC→AC + B).

1. Analyze "The reaction is not a redox reaction": Zn goes from 0 to +2 (oxidation), Ag from +1 to 0 (reduction), so it is a redox reaction. Eliminate this.
2. Analyze "The reaction is an electrolytic cell": Electrolytic cells need external energy, but this reaction is spontaneous (like a voltaic cell), so eliminate.

Answer:

The reaction is a single replacement reaction.