Mixture

Q. The cause of Brownian movement is:

1. Heat changes in liquid state.
2. Convection current.
3. Impact of molecules of dispersion medium on colloidal particles.
4. Attractive forces between particles of the dispersed phase and dispersion medium.

Q.

Define azeotropes. What type of azeotrope is formed by a positive deviation from Raoults law? Give an example.

Q.

Which gas is called dry ice and why?

Q. Why is the percentage of oxygen dissolved in water more than the percentage of oxygen dissolved in ordinary air?

Q.

Classify the following substances into compounds and mixtures :

Carbon dioxide, air, water, milk, common salt, blood, fruit juice, iron sulphide.

Q. What is Volatile components?

Q.

Why emulsion is thermodynamically unstable?

Q.

When carbon dioxide gas is passed through lime water,

1. white precipitate of CaO is formed.

2. colour of lime water disappears.

3. calcium hydroxide is formed.

4. white precipitate of $CaC{O}_3$ is formed.

Q.

Amalgam is a ___ mixture.

1. Liquid in solid

2. Liquid in liquid

3. solid in solid

4. solid in liquid

Q.

Fruit juice is an example of ______ mixture.

Q.

The alloy bronze contains copper and tin. This is a:

1. Homogeneous mixture

2. Heterogeneous mixture

3. Solid solution of two immiscible metals

4. Pure substance

Q.

What is allotropy? Give one example?

Q.

Petroleum is a mixture of groups of compounds such as bitumen, diesel and petroleum gas.

1. True
2. False

Q. How does a centrifuge work?

Q.

The percentage of available chlorine in a pure bleaching powder (${\mathrm{CaOCl}}_2$) sample is ______.

Q.

40. Name the salt used for the manufacture of glass. Give its formula.

Q.

A fizzy drink is a ________ mixture.

Q.

Define allotropy?

Q. Which of the following is an example of a mixture?

1. Sugar

2. Brass

3. CO₂

4. NO₂

Q.

What happens when the solute is added to pure water?

Q.

How is detergent different from soap? These days detergents are preferred to soaps. Give reasons.

Q. Define mixture

Q.

What are detergents chemically? List two merits and two demerits of using detergents for cleansing. State the reason for the suitability of detergents for washing, even in the case of water having calcium and magnesium ions.

Q.

In a mixture, the constituents do not lose their identities. Explain?

Q.

Name the best method of separation of components: petrol and water

Q.

Our body needs iron certain foods are rich in Iron and iron tablets are usually recommended by Doctors but neither the foods nor the tablets are hard like Iron explain

Q.

Define homogeneous mixture

Q. The physical combination of two or more substances is known as.

1. mixture
2. compound
3. element

Q. Why does the introduction of alum makes suspended particles settle down quickly?

Q.

Question 161

Give the chemical name and formula of lime water.