At 25oC, pH range of phenolphthalein is 8-10. At 100oC, textpH range of phenolphthalein would be -

Question

At 25oC, pH range of phenolphthalein is 8-10. At 100oC, textpH range of phenolphthalein would be - (A)  textpH range remain unaffected by the temperature (B)  textpH range is altered to 7 - 9 (C)  textpH range is altered to text7 - text11 (D)  textpH range is altered to text8 - text11

Tardigrade Admin · Accepted Answer

The textpH range of the indicator is pKI n±1. On increase in temperature pKI n decreases therefore textpH range of indicator decreases.

Q. At $2 5^{o} C, p H$ range of phenolphthalein is $8 - 10.$ At $10 0^{o} C,$ $pH$ range of phenolphthalein would be -

$pH$ range remain unaffected by the temperature

$pH$ range is altered to $7$ - $9$

$pH$ range is altered to $7$ - $11$

$pH$ range is altered to $8$ - $11$

The $pH$ range of the indicator is $p K_{I n} \pm 1.$ On increase in temperature $p K_{I n}$ decreases therefore $pH$ range of indicator decreases.

Q. At 25oC,pH range of phenolphthalein is 8−10. At 100oC, pH range of phenolphthalein would be -

pH range remain unaffected by the temperature

pH range is altered to 7 - 9

pH range is altered to 7 - 11

pH range is altered to 8 - 11