Question

How do you find the boiling point of $NaCl$?

Answer 1

The answer to this question is dependent on the general concept of determination of boiling point by the laboratory method. Explain the procedure that is carried out in the laboratory for the required answer.

Complete step by step answer:
In the experiments we carried out in the laboratory of chemistry, we have learnt about the determination of the boiling point, melting points, heating of the mixture and several related determination like the weight of the compound given using the micro balance and so on.
Let us discuss in brief about the determination of boiling point of the compound given that is sodium chloride.
- Sodium chloride is nothing but the compound which is well known as table salt used for the cooking and is the main constituent in the food which gives the taste for the food.
- Sodium chloride is ionic in nature with the strong ionic bond held together with the strong forces of attraction between them.
- Boiling point of sodium chloride cannot be directly determined directly and hence it is determined in the aqueous solution because there is a strong force of attraction between the positive and negative ions and it takes a lot of energy to overcome them and therefore the boiling point of $NaCl$ is very high.
- Thus, the actual boiling point of aqueous sodium chloride was found to be about ${{1413}^{0}}C$
- Basic procedure involved to determine the boiling point in aqueous solution is:
a) The aqueous solution of sodium chloride is taken and non volatile solute is added to it.
b) This elevates the boiling point and the molarity of the solution is to be determined prior.
c) Initial temperature is recorded and the solution is heated until a constant value is reached where further heating does not change the value. This will be the boiling point of the solution.
d) The boiling point elevation changes and is determined using the formula $\Delta T={{K}_{b}}m$

Note: Note that the determination of the boiling point of the ionic crystals is difficult because of their strong force of attraction between the bonds and this needs higher energy to overcome the bond force.