FRANK Solutions for Class 9 Chemistry Chapter 11 - Practical Work

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Chapter 11 - Practical Work 170

Solution 10
Solution 1
On heating certain solids they don't melt and directly get converted to their gaseous form, this process of direct conversion of solids to their gaseous form is called as sublimation. For ex: camphor and ammonium chloride undergo sublimation.
Solution 2
Decrepitation is a process of breaking up of solid particles on heating, which makes a crackling sound. Lead nitrate decrepitate on heating.

Lead nitrate
Solution 3
(a) Zn(NO)3        = white
(b) Cu(NO3)2      = blue
(c) CuSO4.5H2O  = blue
(d) CuSO4          = pale green
(e) K2Cr2O7       = orange
(f) PbS               = black
Solution 4
Solution 5
Solution 6
Solution 7
Solution 8
(a) Rotten egg
(b) Burning sulphur
(c) Nitrogen dioxide
(d) Alkali
(e) Ca(OH)2
(f) Lilac
(g) Brick-red
Solution 9
Point sources of water pollution: Sources of water pollution that discharge directly into the water source are called as point sources of water pollution.
For ex: factories
Non point sources of water pollution: sources of water pollution that remain scattered and don't have specific locations for the discharge of pollutants into particular water bodies are called as non point sources of water pollution.
For ex: run off from fields.