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When hydrochloric aicd is addded to coba...

When hydrochloric aicd is addded to cobalt and nitrate solution at room temperautre, the following reaction takes place and the reaction mixture becomes blue. On cooling the mixture it becomes pink. On the basis of this information mark the corect ansewer.
`underset("pink")[[Co(H_(2)O)_(6)]]^(3+)(aq)+4CI^(-)hArr`
`underset("blue")[CoCI_(4)]^(2-)(aq)+6H_(2)O(l)`

A

`triangleH=0` for the reaction

B

`triangleHgt0` for the reaction

C

`triangleHlt0` for the reaction

D

`triangleH` can not be concluded

Text Solution

Verified by Experts

The correct Answer is:
B
`DeltaH gt 0`, b/c on decreasing the temp. `rx^(n)` goes backward.
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GRB PUBLICATION-COORDINATION COMPOUNDS-E. Stability, Colour and Magnetic Properties of Complexes
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