Question

Name the process associated with the following (a) Dry ice is kept at room temperature and at one atmospheric pressure. (b) A drop of ink placed on the surface of water contained in a glass spreads throughout the water. (c) A potassium permanganate crystal is in a beaker and water is poured into the beaker with stirring. (d) An acetone bottle is left open and the bottle becomes empty. (e) Milk is churned to separate cream from it. (f) Settling of sand when a mixture of sand and water is left undisturbed for some time. (g) Fine beam of light entering through a small hole in a dark room, illuminates the particles in its paths

Answer 1

Explanation:

• a) Dry ice is kept at room temperature and at one atmospheric pressure – Sublimation
• Sublimation is the process in which a solid is converted directly into its gaseous state.
• (b) A drop of ink placed on the surface of water contained in a glass spreads throughout the water. – Diffusion
• Diffusion is the process of random mixing up of particles from a region of higher concentration to a region of lower concentration.
• (c) A potassium permanganate crystal is in a beaker and water is poured into the beaker with stirring. – Dissolution/ diffusion
• (d) An acetone bottle is left open and the bottle becomes empty. – Evaporation
• Evaporation is an endothermic process in which a substance absorbs heat from the surroundings and gets converted into its vapour form.
• (e) Milk is churned to separate cream from it. – Centrifugation
• In the centrifugation technique, the solution is rotated in a centrifugation chamber at very high speeds to separate the phases of the solution.
• (f) Settling of sand when a mixture of sand and water is left undisturbed for some time. – Sedimentation
• Sedimentation is the process of settling down of heavy particles present in a solution at the bottom of the container.
• (g) Fine beam of light entering through a small hole in a dark room, illuminates the particles in its paths. – Tyndall effect