What are the products of a double displacement reaction?
Answer:
One of the products must be a solid precipitate, an insoluble gas, or water.
Explanation:
A double displacement (double replacement) reaction occurs when two aqueous ionic solutions react to produce a solid precipitate, an insoluble gas, or water. If none of these are produced, then a double displacement did not take place.
The general equation for a double displacement reaction is AX + BY → AY + BX, where A and B are cations, and X and Y are anions.
Examples of double displacement reactions.
\(\begin{aligned}
&\mathrm{BaCl}_{2}(\mathrm{aq})+\mathrm{MgSO}_{4}(\mathrm{aq}) \rightarrow \mathrm{BaSO}_{4}(\mathrm{~s}) \downarrow+\mathrm{MgCl}_{2}(\mathrm{aq}) \\
&\mathrm{Na}_{2} \mathrm{~S}(\mathrm{aq})+2 \mathrm{HCl}(\mathrm{aq}) \rightarrow \mathrm{H}_{2} \mathrm{~S}(\mathrm{~g}) \uparrow+2 \mathrm{NaCl}(\mathrm{aq}) \\
&\mathrm{HCl}(\mathrm{aq})+\mathrm{NaOH}(\mathrm{aq}) \rightarrow \mathrm{NaCl}(\mathrm{aq})+\mathrm{H}_{2} \mathrm{O}(\mathrm{l})
\end{aligned}\).
The down arrow ↓indicates the formation of a solid precipitate, and the up arrow ↑indicates the formation of a gas. You can also use the symbols (s) and (g).