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Hello students welcome here in this question.
00:02
When a sample is heated, water is absorbed at the top of the tube.
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So sample is heated.
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Then what happens? so the water in this sample gets evaporate and gets condensed on the walls of the test tube.
00:22
So the compound melts and changes color.
00:26
The residue is not entirely changed.
00:29
Soluble so it is most likely select one they are asking so what is that compound maybe they are asking the first one is efflorescent so efflorescent is a salt that loose water when they are kept contact with air, dry air, okay? so not on heating, they are when kept on dry heat.
01:06
So they lose their water and changes its color.
01:10
Okay, that type of compounds are known as a florescent compound so it is not covered for us.
01:17
Next, a hydrate.
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A hydrate is a salt or compound containing water molecules are known as a hydrate.
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For example, c -u -s -o -4, pentahydrate and cobalt chloride hexahydrate.
01:45
So these are initially if you see the color is blue for this one and this one is a pink.
01:54
So when it loses water, it turns to violet and then after so when it is a dehydrate it is violet when it is a nil only cobal chloride then it turns to blue color okay entirely so here if you see copper sulphate is blue in presence of five h2o molecules after heating it loses this water and forms copper sulfate so there is no any water molecule and this one is colorless.
02:35
So a hydrate can change the color on heating.
02:41
So it is a correct answer for the given question.
02:45
And if you see a carbohydrate, so carbohydrate releases water, we know that because there are molecules monosaccharide units are present in carbohydrates...