Neutralization reaction to obtain the crystal of sodium chloride

Experiment 5: Neutralization reaction to obtain the crystal of sodium chloride

OBJECTIVE

TO CARRY OUT THE NEUTRALIZATION REACTION BETWEEN HYDROCHLORIC ACID AND SODIUM HYDROXIDE AND TO OBTAIN THE CRYSTAL OF SODIUM CHLORIDE IN PURE AND DRY STATE

APPARATUS REQUIRED

1. Beaker
2. Test tube
3. Glass Red
4. Wire Gauze
5. Porcelain Basin

CHEMICALS REQUIRED

1. NaOH
2. HCl
3. Litmus Paper
4. Phenolpthalein.

THEORY

The chemical reaction in which acid and base react with each other resulting in the formation of product like salt and water is called neutralization reaction During neutralization reaction, mutual exchange of radicals take place between acid and base.

Hence, the neutralization reaction is also a double displacement reaction. In the reaction between NaOH and HCl, the mutual exchange of radicals takes place giving salt and water.

\underset{Acid}{HCl}+\underset{Base}{NaOH}\rightarrow \underset{Salt}{NaCl}+ \underset{Water}{H_{2}O}

In Ionic form,

\begin{align*} 
H^{+}+Cl^{-}+Na^{+}+OH^{-} &\rightarrow Na^{+}+Cl^{-}+H_{2}O\\
H^{+}+OH^{-} &\rightarrow H_{2}O
\end{align*}

Therefore, the neutralization reaction is the combination of H+ and OH- to form a water molecule.

PROCEDURE

A half test tube full of bench hydrochloric acid was taken in a small beaker A half test tube full of bench sodium hydroxide was added a little at a time with the help of a glass tube. The mixture was stirred constantly with a glass rod. A neutral point was obtained by testing the solution with red and blue litmus paper and adding the required chemical accordingly.

The solution was filtered and evaporated to get dry and solid sodium chloride. A pinch of salt was taken from the remains of evaporation. The salt is taken in a test tube and dissolved in water. Then, a few drops of silver nitrate solution was added to the test tube. The curdy white precipitate was formed Indicating the presence of chloride salt.

OBSERVATION TABLE

RESULT

Common salt was obtained by neutralization of HCl by NaOH followed by evaporation.

CONCLUSION

We can obtain common salt from the neutralization reaction of HCl and NaOH through evaporation.

PRECAUTIONS

1. The mixture should be completely neutral.
2. All the glass wares should be handled with care.
3. Separate glass tubes should be used for acid and base bottles