## Saturday 27 April 2013

### CBSE Class 9 - Science Practical (SA1) - To determine the melting point of ice.

To Determine The Melting Point of Ice

[MCQs asked in CBSE examination]

Q1: Melting point of ice is

(a) 0° C
(b) 10° C
(c) 100° C
(d) 50° C

Q2: Dry ice is

(a) solid state of water
(b) solid ammonium chloride
(c) solid oxygen
(d) solid carbon dioxide

Q3: When half of the ice gets melted, the temperature shown by thermometer is

(a) 100° C
(b) 0° C
(c) starts increasing from 0° C
(d) starts decreasing from 0° C

Q4: When common salt is added to ice, what happens to its melting point?

(a) Melting point temperature remains the same.
(b) Melting point temperature increases.
(c) Melting point temperature decreases.
(d) Anything is possible,depends on the quantity of salt added.

Q5: The density of ice at its melting point is

(a) 1 kg/m3
(b) equal to the density of water
(c) more than the density of water
(d) less than the density of water

Q6: Whose temperature is lowest?

(a) 1 kg ice
(b) 1 kg melting ice
(c) 10 kg ice
(d) mixture of 1 kg ice and salt

Q7: While determining the melting point,the position of thermometer should be

(a) the bulb of thermometer should partially touch the ice
(b) the bulb should touch the base of container(completely surrounded by ice)
(c) the bulb should not touch the base of container(completely surrounded by ice)
(d) the bulb should be above the surface of ice.

Q8: What is the temperature at which ice and water exist together under atmospheric pressure?

(a) at 0° C
(b) below 0° C
(c) above 0° C
(d) never

Q9: The ice used to find the melting point is preferably made from

(a) distilled water
(b) tap water
(c) water mixed with salts
(d) crushed ice is used

Q10: The normal atmospheric pressure is

(a) 760 cm of mercury
(b) 60 cm of mercury
(c) 76 cm of mercury
(d) 76 mm of mercury

Here is an excellent you tube video posted by CDAC and Amrita Labs:

1: (a) 0 C
2:  (d) solid carbon dioxide
3:  (b) 0 C
4:  (c) Melting point temperature decreases.
5:  (b) equal to the density of water
6: (d) mixture of 1 kg ice and salt
7: (c) the bulb should not touch the base of container(completely surrounded by ice)
8: (a) at 0 C
9: (a) distilled water
10: (c) 76 cm of mercury