Chapter 1

What is the effect of addition of impurities on freezing point and boiling point of a substance?

What is a freezing mixture? Give an example.

Define melting point. What is the effect of pressure on melting point?

What are cohesive forces and adhesive forces?

Cotton clothes producing cooling effect during summer is an application of _________ .

Why do the wet clothes dry faster on windy day?

Is it possible to liquify \(\mathrm{CO}_{2}\) gas at \(50{ }^{\circ} \mathrm{C}\) ? Give reason.

A mixture of sand and \(\mathrm{NH}_{4} \mathrm{Cl}\) can be separated by _______ method.

Define latent heat of fusion. Give its value for ice.

What is meant by atomicity of an element? Give some examples of polyatomic elements.

Distinguish between filtration and centrifugation.

Give an example each for solid-liquid and solid-solid homogenous mixtures.

The atomicity of element phosphorus is _______ .

A metal 'A' reacts with a metallic chloride of 'B' to give metal 'B'. But, metallic chloride of 'A' cannot give metal 'A' on reaction with metal 'B'. What conclusion can you draw from this?

Give an example for a liquid-liquid heterogeneous mixture. Suggest a method of separation for it.

How do you separate a mixture of (a) \(\mathrm{CO}_{2}\) and \(\mathrm{O}_{2}\) (b) \(\mathrm{H}_{2}\) and \(\mathrm{O}_{2}\)

The formation of phosphorus pentachloride from phosphorus trichloride and chlorine gas is a _____ type of combination reaction.

The addition of \(\mathrm{MnO}_{2}\) to \(\mathrm{KClO}_{3}\) decreases the temperature at which \(\mathrm{KClO}_{3}\) decomposes because \(\mathrm{MnO}_{2}\) added acts as a ____ catalyst.

What is paper chromatography?

Why is sodium stored in kerosene?

A reaction of decomposition of a compound \(\mathrm{AB}\) is accompanied by absorption of some heat energy. What is the sign of \(\Delta \mathrm{H}\) ?

The temperature above which no amount of pressure can cause a gas to liquify is _________

What is sublimation? Give some examples.

Suggest a method of separation for a mixture of sodium chloride and ammonium chloride. Explain the process.

When two ice cubes are pressed, they join together. Explain the principle involved.

Why are cotton clothes preferable in summer?

How is liquefaction different from condensation?

Distinguish between evaporation and boiling.

When a glass of ice cold water is taken in a glass, water drops are formed on the outer surface of the glass. Give reason.

What is double decomposition reaction? Give an example each for neutralisation and precipitation reaction.

Why is it not possible to displace fluorine from metallic fluorides by any other halogen?

Explain the process of condensation with respect to kinetic molecular theory.

What is critical temperature? How does it affect the liquefaction of gas?

Why does steam cause more burns than boiling water?

List out the differences between physical and chemical changes.

What are the different types of combination reactions? Give an example of each.

Suggest the possible methods of separation of liquid gas mixtures. Explain each method with an example. Explain the factors affecting (a) melting point (b) boiling point (c) evaporation

Explain the factors affecting (a) melting point (b) boiling point (c) evaporation

Give the postulates of kinetic molecular theory of matter. Explain the process of melting on the basis of this theory.

Explain the process of separation of different constituents in coloured ink.

Explain the following methods of separation with an example each. (a) Fractional crystallization (b) Sedimentation and decantation (c) Preferential liquefaction (d) Fractional distillation