Question

How can you obtain pure water from a salt water mixture (or salt solution ) ?Draw a neat and labelled diagram of the apparatus you would use to obtain pure water from salt water mixture (or salt -solution ).
​

Answer 1

C) The initial temperature of water in the vessel is maintained at 10
∘
C. Due to freezing at the center, the temperature of water begins to fall. The water contracts and its increases.

(e) As the density of water increases, the cold water goes to the bottom of the vessel and the temperature of the waterfalls to 4
∘
C

(a) as shown by the lower thermometer and this remains constant.

( d) The temperature of water at the center falls below 4
∘
C, then the water expands instead of contracting, so, that its density decreases, therefore the water below 4
∘
C goes to the upper portion

(f) The temperature of waterfalls till 0
∘
C, as shown by the upper thermometer.

(b) Water at 0
∘
C freezes into ice and a layer of ice is formed at the top surface because the density of ice is less than that of water.

(g) Being a bad conductor of heat, ice prevents the loss of heat from the water below it to the surroundings.