Question

What are the products of a double displacement reaction?

Answer 1

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"` `rarr` `"AY + BX"`, where `"A"` and `"B"` are cations, and `"X"` and `"Y"` are anions.

Examples of double displacement reactions.

`"BaCl"_2("aq")" + MgSO"_4("aq")"` `rarr` `"BaSO"_4("s")darr"+ MgCl"_2("aq")"`

`"Na"_2"S(aq)" + "2HCl(aq)"` `rarr` `"H"_2"S(g)"uarr"+ 2NaCl(aq)"`

`"HCl(aq)" + "NaOH(aq)"` `rarr` `"NaCl(aq)" + "H"_2"O(l)"`

The down arrow `darr` indicates the formation of a solid precipitate, and the up arrow `uarr` indicates the formation of a gas. You can also use the symbols `("s")` and `("g")`.