Question

How do you predict the products in acid-base reactions? Which salt is formed and how?

Answer 1

Hint: You predict the products of acid-base reactions by pairing each cation with the anion of the other compound.

Complete step by step answer:
Neutralization reaction- A neutralization reaction can be defined as a chemical reaction in which an acid and base quantitatively react together to form a salt and water as products.
 When the acids react with bases, they neutralize each other's effect and thus it is called a neutralization reaction, energy is released during this reaction and hence it is exothermic in nature.
The products formed by this reaction are salt and water.
\[Acid{\text{ }} + {\text{ }}Base\] →\[\;Salt{\text{ }} + {\text{ }}Water\]

For example- Let's use the neutralization of stomach acid (\[HCl\] ) by milk of magnesia \[\left[ {Mg{\text{ }}{{\left( {OH} \right)}_2}} \right]\] as an example.
\[HCl{\text{ }} + {\text{ }}Mg{\text{ }}{\left( {OH} \right)_2}\] →?
(a.) For products, combine the \[{H^ + }\] and \[O{H^ - }\] ions to make\[{H_2}O\] .
Then combine the positive and negative ions to make a salt.
Remember to balance the positive and negative charges in the salt.
In this case, \[M{g_2}\] + and\[C{l^ - }\] make\[MgC{l_2}\] .
\[\left( {H{\text{ }} + {\text{ }}C{l^ - }} \right)\] + \[\left( {M{g_2} + O{H^ - }} \right)\] → \[\left( {M{g_2} + C{l^ - }} \right)\] +\[\;\left( {H{\text{ }} + O{H^ - }} \right)\]
\[HCl\] + \[Mg{\text{ }}{\left( {OH} \right)_2}\] → \[MgC{l_2}\] + \[{H_2}O\]
(b.) Balance the equation.
\[2HCl\] + \[Mg{\text{ }}{\left( {OH} \right)_2}\] →\[MgC{l_2}\] + \[2{H_2}O\]

Note:
When acid reacts with base, then the salt formed may be acidic, may be basic or may be neutral.
It depends on three things: -
1) when strong acid reacts with a weak base, then the salt formed will be acidic salt.
2) When a strong base reacts with weak acid, then the salt formed will be basic salt.