Question

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

Answer 1

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.