Question

Sonali mixed a packet of salt in a small amount of sand and then tried to recover the salt by the usual processes of sedimentation, decantation or filtration followed by evaporation. To her surprise, she could recover only a small part of the salt that she had taken. The possible reasons could be.
I. Salt also got evaporated along with water.
II. The quantity of salt was much more than that required to form a saturated solution.
III. The undissolved salt remained mixed with sand.
IV. The quantity of water taken was insufficient to dissolve all the salt.

• A. II and III only
• B. I and IV only
• C. II, III and IV only
• D. All of these

Answer 1

The correct option is C II, III and IV only

Sonali mixed a packet of salt in a small amount of sand and recovered only a small part of the salt that she had taken. This could be due to the following reasons:
(i) The amount of salt was much more that it required a large amount of water to dissolve all the salt.
(ii) To form a saturated solution, lesser quantity of salt was required but she took a large amount of salt.
(iii) The undissolved salt remained mixed with sand.
Salt does not evaporate along with water.