Name the technique used to separate the following:

• (a) Butter from curd.
• (b) Salt from seawater.
• (c) Camphor from salt?

To separate the substances you've mentioned, different techniques are employed based on their physical and chemical properties. Let's break down each one:

Separation Techniques Explained

1. Butter from Curd

The technique used to separate butter from curd is known as **churning**. This process involves agitating the curd, which causes the fat molecules to clump together and form butter. When you churn curd, the agitation breaks down the emulsion of fat in the curd, allowing the butter to separate from the buttermilk. This method is quite traditional and can be done using a simple churn or even a jar if you shake it vigorously.

2. Salt from Seawater

To extract salt from seawater, the method employed is called **evaporation**. In this process, seawater is heated, causing the water to evaporate and leaving behind the salt crystals. This technique takes advantage of the fact that salt has a much higher boiling point than water. Once the water evaporates completely, you are left with salt. This method is commonly used in salt production and can also be observed in nature when seawater evaporates in hot climates, leaving salt flats behind.

3. Camphor from Salt

The separation of camphor from salt can be achieved through **sublimation**. Camphor is a substance that can transition directly from a solid to a gas without becoming liquid first. When you heat a mixture of camphor and salt, the camphor sublimates, and the gas can then be cooled to form solid camphor again, while the salt remains behind. This technique is particularly useful for separating substances that have significantly different physical properties, such as boiling points or sublimation points.

Summary of Techniques

• Churning: Used for separating butter from curd.
• Evaporation: Employed to extract salt from seawater.
• Sublimation: Utilized for separating camphor from salt.

Each of these techniques leverages specific physical properties of the substances involved, making them effective for separation. Understanding these methods not only helps in practical applications but also deepens your grasp of the principles of chemistry and physical science.