IIT JEE , AIEEE Forum - Chemistry , Inorganic Chemistry - why blue copper sulphate becomes white on heating ?

mayank_simghal

why blue copper sulphate becomes white on heating ?

coolriya

due to dehydration............

monith234

copper sulphate SOLUTION ON EXPOSURE TO AIR LOSES 2 WATER MOLECULES TO FORM A PALE BLUE SOLUTION,ON HEATING THIS COMPOUND TO 100C IT LOSES 2 MORE WATER MOLECULES TO
FORM BLUISH WHITE SOLUTION AND THEN HEATED TO 230C IT BECOMES AN ANHYDRATE WHITE POWDER

yugu901234

because on heating it loses water af crystallisation and becomes anhydrous which is white in colour....

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sriram.a

CuSO4.5H2O on heating CuSO4

karansingh

CuSO4.5H2O is blue due to effect of water of crystallisatiion

on heating, H2O is evaporated and CuSO4 is left which is white in colour.

For most colored salts, it is the water of crystallisation which gives them color.

abrambenny

Are u asking for the reason for the blue colour? I mean the physical reason??? If not the loss in colouration is due to loss o water of crystallisation on heating.

Euphorio

cos it loses da water of crystallisation

anay_pat

CUSO4.5H2O on heating loses water of crystallisation which is responsible for its colour and crystalline form.Thus it becomes anhydrous Copper Sulphate(CuSO4) which is colourless.

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harsha_27

Can anybody explain me why and how the water of crystallization in CuSO4.5H2O gives it its color?

nitigya

CuSO₄.5H₂O exists as complex and when weak field ligand approaches the the copper ions , splitting up of d orbitals take place and then only d-d transition takes place which provides the colour. when the salt is heated the water molecule is lost and now the d orbitals r no longer split and hence it looses its colour

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pink_ele

in hydrated form it exists as an aqua complex which gives d colour due to above stated reason
:)
on heating water is lost thus salt is colour less

studyid

in the hydrated state .....copper suplhate solution appears blue due to the photo sensitivity ...... of the light falling on it ....

heat ..it ....take out the water of crystallisation and it will b white in colour .

when it is in hydrated state .....the electrons gain energy in the form of the photons from the light .......so the electrons make transition .......

and the wavelength corresponding to the transition is blue ......

and so the copper sulphate solutions appears blue in colour

dakshayadav

copper sulphate is CuSO4.5H2O n is blue in colour due to water of crystallisation
upon heatine it loses those 5 water of crysallisation molecules and becomes anhydrous salt which is white in colour

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