Olympiad Test: Matter in Our Surroundings- 1 - Class 9 MCQ

The substances in decreasing order of force of attraction between the particles are-

1. Sugar (being a solid, has the highest force of attraction between the particles)

2. Alcohol (being a liquid, has comparatively lesser force of attraction between the particles than sugar)

3. Nitrogen (being a gas, has the lowest force of attraction between the particles)

It is due to the latent heat as the heat supplied to increase the temperature of the substance is used up to transform the state of matter of the substance hence the temperature stays constant.

Hence the temperature remains constant as all the heat is used up and no external heat is released or absorbed.

After the mixture is dissolved in water, sodium chloride gets dissolved, we only get Sulphur. Now we can filter the solution through filter paper and heating the salt solution will give us the salt crystals again. Using this method, Sodium Chloride and Sulphur can be separated.

Temperature on Kelvin scale = Temperature

on Celsius scale + 273

(i) = 0 + 273

= 273 K

(ii) = – 6 + 273

= 267 K

(iii)= 273 + 273

= 546 K

The boiling point is the temperature at which the vapour pressure of the liquid equals the environmental pressure surrounding the liquid. Atmospheric pressure is due to air above any given point. The atmospheric pressure at high altitudes like hill station is less than at the sea level.Thus, vapour pressure will equal atmospheric pressure at a comparatively low temperature. Thus, the boiling point of water is reduced less than at sea level or <100°C.

(i) The particles of matter are very small.

(ii) The particles of matter attract each other.

(iii) The particles of matter have space between them.

(iv) All the particles of matter are constantly moving.

Also, particles are not stable, they all have some kinetic energy so move constantly.

So, option C is incorrect.