If a copper coin is dipped into a solution of silver nitrate, over time, a shiny greyish-white coating appears on the copper coin, and the solution turns bluish. Explain the observation based on the reactivity of metals.
Options
Silver is more reactive than copper, so copper displaces silver.
Copper is more reactive than silver, so copper displaces silver from its salt solution.
Both copper and silver are equally reactive, causing a simple mixing.
This is a physical change, where silver just settles on the copper.
Explanation
This observation is due to a displacement reaction. Copper is more reactive than silver. When a copper coin is dipped into silver nitrate solution (), the more reactive copper displaces the less reactive silver from its salt solution. The silver metal gets deposited on the copper coin, appearing as a shiny greyish-white coating. Simultaneously, copper goes into the solution to form copper nitrate (), which is blue in colour, causing the solution to turn bluish. This demonstrates the reactivity series of metals, where a more reactive metal can displace a less reactive metal from its compound.