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The human eye is sensitive to colour dif...

The human eye is sensitive to colour differences of indicator only when the ratio `[In^(-) ] // [Hin]` is greater then 10 (or) smaller than 0.1. What should be the minimum change in the pH of solution of observe a complete colour change .` (pK_(In) =5) ` .

A

`1.2`

B

` 1.4`

C

` 1`

D

`2`

Text Solution

Verified by Experts

The correct Answer is:
D
`pH " range" =[PK_(I_n) -1, pK_(I_n) +1]`
` therefore ` change =2
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Knowledge Check

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