Chemistry
Give reasons for the following:
Particles of matter possess energy called kinetic energy.
Solids cannot be compressed, but gases are highly compressible.
Kinetic energy of molecules of gases is very large & of solids, the least.
On heating a sublimable solid, the molecules break free & escape from surface of the solid directly into vapour.
Particles of matter move more rapidly on application of heat.
Answer
Particles of matter are in continuous motion and hence possess energy called kinetic energy.
As inter-particle space in solids is minimum, hence, they cannot be compressed. Gases on the other hand, have very large inter-particle space, hence are highly compressible.
As inter-particle space in gases is very large and inter-particle attraction is negligible, hence they are in random motion all the time and posses high kinetic energy whereas solids have minimum inter-particle space, maximum inter-particle attraction and they can move only about their own position. Hence they have least kinetic energy.
Sublimable solid have very low force of attraction between their particles. On heating, these solids overcome the inter-particle attraction and the molecules break free & escape from surface of the solid directly into vapour.
Application of heat increases the kinetic energy of the particles which then move more randomly.
Related Questions
Select the correct answer from A, B, C, D & E for each statement given below:
A: Solid
B: Vaporization
C: Ion
D: Gases
E: Heat
An atom or group of atoms — having a resultant charge.
The state of matter which has — least density & no free surfaces.
In Landolt's experiment — the form in which the chemical energy stored up in the reactants — is released.
The process of change of a liquid into vapour [gas] on heating.
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.
The heat energy supplied to the liquid is absorbed by its molecule & stored as which form of energy.
How does the stored energy, have effect on inter-particle space.
State why the inter-particle attraction decreases to negligible.
At what point will the particles become free and escape as gas.
Complete the statements by filling the blanks with the correct word from the bracket.
In naphthalene, the inter-particle attraction is …………… [high/low].
The law of conservation of mass, is strictly valid if mass and …………… [energy/volume] are considered together.
When inter-particle space increases, the inter-particle attractive force …………… [decreases/increases]
Kinetic energy of molecules in helium is …………… [large/very large] compared to the kinetic energy of molecules in water.
Conversion of vapour [or gas] into a liquid is termed …………… [liquefaction/vaporization].
Complete the blanks with reference to interconversion of matter on basis of kinetic theory - with the word 'increases', 'decreases', 'gain', 'lose' or 'overcome' in each case.
During melting of solids, the inter-particle space ……………
During vaporization, the liquid particles …………… energy.
During liquefaction, the particles …………… energy.
During solidification, the inter-particle space ……………
During sublimation the inter-particle attraction is ……………