Question

The conductance of an emulsion increases on adding common salt. What type of emulsion is this?

Answer 1

Hint: Emulsions can be defined as the mixture of two liquids that would not normally mix. We can also say emulsions are a mixture of two immiscible liquids. They are found to be milky in appearance and the suspended material may be colloidal in nature.

Complete answer:
The colloidal solution in which both the dispersed phase and the dispersion medium are liquid is called an emulsion. An emulsion is a colloid in which liquids that do not mix are spread throughout each other. Emulsifying is usually done by slowly adding one ingredient onto another while mixing it simultaneously. This will disperse and suspend tiny droplets of one liquid through another. They have a cloudy appearance due to many phase interfaces scattering light passing through the emulsions.
Emulsions can be classified as;
Oil in water emulsion: In this type of emulsion, the dispersed phase is oil and the dispersed medium is water. For example- milk.
Water in oil emulsion: In this type of emulsion dispersed phase is water and the dispersed medium is oil. For example- Butter.
Now coming to our question;
The conductance of an emulsion was found to increase on adding common salt ( $NaCl$ ). This emulsion is oil in water type emulsion. $NaCl$ forms $N{a^ + }$ and $C{l^ - }$ ions which will increase the conductance of emulsion.

Note:
It should be noted that the term emulsion is also applied to a group of mixed systems called as solutions, or gels or suspensions. An emulsion is a thermodynamically unstable system and hence emulsions have minimum stability. Emulsions also have wide applications