Viraf J. Dalal solutions for New Simplified Middle School Chemistry [English] Class 8 chapter 1 - Matter [Latest edition]

Explain the meaning of the term ‘matter’.

Matter in any state is composed of small particles – molecules, atoms, or ions. Differentiate the terms above in Italics.

Differentiate between the-two characteristics of matter – ‘mass’ & ‘weight’.

State which of the three states of matter Le. solids, liquids or gases – have

(a) No definite volume
(b) A definite shape
(c) High density
(d) No free surfaces
(e) Particles – which diffuse very easily.

State the main postulate of the kinetic theory with special reference to Inter-particle space.

State the main postulates of the kinetic theory with special reference to – Inter-particle attraction.

State the main postulates of the kinetic theory with special reference to – Energy possessed by particles of matter.

State in which of the following examples ie. a piece of wood, water, light gas is the Inter-particle space maximum.

State in which of the following examples ie. a piece of wood, water, light gas is the Inter-particle attraction maximum.

State in which of the following examples ie. a piece of wood, water, light gas is the Energy possessed by particles of matter, very large.

In which of the three states of matter – solids, liquids, or gases is the movement of atoms about their own position. Give a reason for the same.

‘Inter-particle attraction between atoms of gases is very weak’. State five properties of gases which correlate as a consequence of the weak inter-particle attraction between particles of gases.

What is inter-conversion of matter. Give the meaning of the terms involved in inter-conversion of matter

(a) Melting
(b) Vaporisation
(c) Liquefaction or condensation,
(d) Solidification or freezing
(e) Sublimation.

Draw a labelled schematic diagram representing the terms (a) to (e) involved in the inter-conversion of matter.

With reference to inter-conversion of matter – on the basis of kinetic theory – explain in brief the conversion of A solid into a liquid With special reference to inter-particle space & interparticle attraction at the different stages of conversion.

With reference to inter-conversion of matter – on the basis of kinetic theory – explain in brief the conversion of A liquid into vapour [or gas] With special reference to inter-particle space & interparticle attraction at the different stages of conversion.

With reference to inter-conversion of matter – on the basis of kinetic theory – explain in brief the conversion of Vapour [or gas] into a liquid With special reference to inter-particle space & interparticle attraction at the different stages of conversion.

With reference to inter-conversion of matter – on the basis of kinetic theory – explain in brief the conversion of A liquid into a solid With special reference to inter-particle space & interparticle attraction at the different stages of conversion.

On the basis of kinetic theory explain why ammonium chloride sublims and goes from solid-state directly into vapour state.

State the ‘law of conservation of mass’.

State the main points of Landolt’s experiment for experimental evidence of the law. 

Select the correct answer from A, B, C, D & E for the statement given below:

An atom or group of atoms _________ having a resultant charge.

Select the correct answer from A, B, C, D & E for the statement given below:

The state of matter which has ___________ least density & no free surfaces.

Select the correct answer from A, B, C, D & E for the statement given below:

In Landolt’s experiment – the form in which the chemical energy stored up in the reactants __________ is released.

Select the correct answer from A, B, C, D & E for the statement given below:

The process of change of a liquid into vapour, [gas] on heating.

Select the correct answer from A, B, C, D & E for the statement given below:

The state of matter, where the inter-particle attraction between particles is maximum.

With reference to the liquid state of matter – answer the following

On heating, the liquid, do the particles gain or lose energy.

With reference to the liquid state of matter – answer the following

The heat energy supplied to the liquid is absorbed by its molecule & stored as which form of energy.

With reference to the liquid state of matter – answer the following

How does the stored energy, have an effect on inter-particles space.

With reference to the liquid state of matter – answer the following

State why the inter-particles attraction decreases to negligible.

With reference to the liquid state of matter – answer the following

At what point will the particles become free and escape as a gas.

Complete the statement by filling the blank with the correct word given below.

In naphthalene, the inter-particle attraction is _______.

Complete the statement by filling the blank with the correct word given below.

The law of conservation of mass is strictly valid if mass and _________ are considered together.

Complete the statement by filling the blank with the correct word given below.

When inter-particle space increases, the inter-particle attractive force _______________.

The kinetic energy of molecules in helium is ______ compared to the kinetic energy of molecules in water. 

Complete the statement by filling the blank with the correct word given below.

Conversion of vapour [or gas] into a liquid is termed ____________.

Give reason for the following 

Particles of matter possess energy called kinetic energy.

Give the reason for the following 

Solids cannot be compressed, but gases are highly compressible.

Give the reason for the following: 

The kinetic energy of molecules of gases is very large & of solids, the least.

Give the reason for the following 

On heating a sublimable solid, the molecules break free & escape from the surface of the solid directly into vapour.

Give the reason for the following 

Particles of matter move more rapidly on the application of heat.

Complete the blank with reference to interconversion of matter on the basis of kinetic theory-with the word ‘increase’, ‘decreases’, ‘gain’, ‘lose’, or ‘overcome’ in following case.

During the melting of solids, the inter-particles space __________.

Complete the blank with reference to interconversion of matter on the basis of kinetic theory-with the word ‘increase’, ‘decreases’, ‘gain’, ‘lose’, or ‘overcome’ in the following case.

During vaporization, the liquid particles ____________ energy.

Complete the blank with reference to interconversion of matter on the basis of kinetic theory-with the word ‘increase’, ‘decreases’, ‘gain’, ‘lose’, or ‘overcome’ in the following case.

During liquefaction, the particles ________ energy.

Complete the blank with reference to interconversion of matter on the basis of kinetic theory-with the word ‘increase’, ‘decreases’, ‘gain’, ‘lose’, or ‘overcome’ in the following case.

During soldification, the inter-particle space __________ gently.

Complete the blank with reference to interconversion of matter on the basis of kinetic theory-with the word ‘increase’, ‘decreases’, ‘gain’, ‘lose’, or ‘overcome’ in the following case.

During sublimation, the inter-particle attraction is _______________.