Answer the following: [3 MARKS]
(a) When is it useful to apply sedimentation and decantation?
(b) Give two examples where these methods are used?
(c) Explain the process.
Answer the following: [3 MARKS]
(a) When is it useful to apply sedimentation and decantation?
(b) Give two examples where these methods are used?
(c) Explain the process.
Identification : 1 Mark
Examples : 0.5 Mark each
Explanation : 1 Mark
(a) Sedimentation and decantation are used to separate coarse particles of a solid which is insoluble in the liquid. Sedimentation works on the property that the heavy particles settle down due to gravity.
(b)
i. Sand in muddy water can be separated using sedimentation and decantation technique.
ii. Dust can be separated from rice using sedimentation and decantation. When water is added, rice grains being heavy settle down while the dust remains floating on the water.
(c) The particles of sand settle down to the bottom of the beaker. The settling down of heavier particles is called sedimentation. We can transfer the clear water in the upper layer (supernatant) carefully to another beaker without disturbing the solid particles. This is called decantation.
Identification : 1 Mark
Examples : 0.5 Mark each
Explanation : 1 Mark
(a) Sedimentation and decantation are used to separate coarse particles of a solid which is insoluble in the liquid. Sedimentation works on the property that the heavy particles settle down due to gravity.
(b)
i. Sand in muddy water can be separated using sedimentation and decantation technique.
ii. Dust can be separated from rice using sedimentation and decantation. When water is added, rice grains being heavy settle down while the dust remains floating on the water.
(c) The particles of sand settle down to the bottom of the beaker. The settling down of heavier particles is called sedimentation. We can transfer the clear water in the upper layer (supernatant) carefully to another beaker without disturbing the solid particles. This is called decantation.
