What is the difference between a double replacement and an acid-base reaction?

1 Answer
Aug 29, 2017

Answer:

Although similar, neutralisation reactions do not displace the #H# and #OH# atoms, but rather react together to form water. This is not evident in double displacement reactions.

Explanation:

Generally speaking, a double displacement reaction has a formula of #AB+CD->AD+CB#. This normally occurs between two ionic compounds but is not restricted to it *needs confirmation.

An acid-base reaction is a neutralisation reaction in which the hydrogen and oxygen atoms within the acid and base yields water, while the other reactants form a salt.

This means that they don't displace each other, but rather forms a new compound.

Examples:

Double displacement

#BaCl_"​2" ​​ (aq)+Na_"2"SO_"4" ​​ (aq)→BaSO_"4" ​(s)+2NaCl (aq)#

You see that the #AB+CD->AD+CB# formula applies, where:
=> #A# refers to #Ba#.
=> #B# refers to #Cl#.
=> #C# refers to #Na#.
=> #D# refers to #SO_"4"#.

Neutralisation

#H_"2"SO_"4" + 2KOH -> K_"2"SO_"4" + 2H_"2"O#

As you can see, the #H# and #OH# atoms form water, while the other reactants (#K# and #SO_"4"#) form #K_"2"SO_"4"#.

Hope this helps :)