At 25° C,pH range of phenolphthalein is 8-10. At 100° C, pH range of phenolphthalein would be

Question

At 25° C,pH range of phenolphthalein is 8-10. At 100° C, pH range of phenolphthalein would be (A) pH range remain unaffected by the temperature (B) pH range is altered to 7 - 9 (C) pH range is altered to 7-11 (D) pH range is altered to 8-11

Tardigrade Admin · Accepted Answer

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

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

$p H$ range remain unaffected by the temperature

$p H$ range is altered to $7$ - $9$

$p H$ range is altered to $7 - 11$

$p H$ range is altered to $8 - 11$

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

Q. At 25∘C,pH range of phenolphthalein is 8−10. At 100∘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