To Demonstrate that miscible liquids dissolve in each other and immiscible do not By Dr. Riaz

Описание: Some pairs of liquids are characterized by miscibility, some by immiscibility, and some by partial miscibility. When two miscible liquids are mixed, not distinct layer forms between the two liquids, whereas when two immiscible liquids are combined, one observes a distinct layer that acts as a boundary between the two liquids. This boundary is called the meniscus. Miscible pairs of liquids form homogeneous solutions whereas immiscible pairs of liquids form inhomogeneous solutions.
In general, chemical polarity explains miscibility: polar liquids (i.e., liquids made of polar molecules) are miscible among themselves and nonpolar liquids (i.e., liquids made of nonpolar molecules) are also miscible among themselves. Polar and nonpolar liquids are immiscible with each other.
Think!
1. What is the difference between miscible and immiscible liquids?
Answer: Miscible liquids are mixed with each other forming homogeneous mixture while immiscible liquid do not mix with each other uniformly forming two layers.
2. Why ethanol is miscible with water?
Answer: Ethanol is mixed with water due to hydrogen bonding.
3. Why oil is immiscible with water?
Answer: Because there is no attractive force between oil and water molecules.
4. Which pair of the following liquids are miscible?
a. Water and olive oil
b. Mustard oil and olive oil
c. Water and chloroform
Answer: b. Mustard oil and Olive oil
Post Lab Activities:
1. How will you remove grease stains from the cotton fabrics?
Answer: By the application of detergents.
2. Water insoluble lubricants are used to run machines. What types of soaps are used to clean these machines?
Answer: Detergents
3. Why is it generally easy to remove stains from synthetics fabrics than from the cotton fabrics?
Answer: Because stains doesn’t strictly adhere to synthetics fabrics. Synthetics fabrics are oil resistant.
Brain teaser!!
1. Household polish and paint workers often use kerosene oil during their work. Being insoluble in water, kerosene oil cannot be completely removed by washing hands with soap. Think of a method to wash hands so that they are free from the smell of kerosene oil.
Answer: By using spirit or alcohol the smell of kerosene can be removed.