Home
Class 11
CHEMISTRY
K(b) of an acid-base indicator H In is 1...

`K_(b)` of an acid-base indicator `H` In is `10^(-9)`. The `pH` at which its `10^(-3) (M)` solution shows the colour change

A

`9`

B

`7`

C

`5`

D

`3`

Text Solution

Verified by Experts

The correct Answer is:
C
`K_(a)K_(b)=10^(-14)` or `K_(a)=K_(in)=10^(-5)`
`:. [H^(+)]=10^(-5)` or `pH=5`
Promotional Banner

Topper's Solved these Questions

  • IONIC EQUILIBIUM

    A2Z|Exercise Section B - Assertion Reasoning|21 Videos

  • IONIC EQUILIBIUM

    A2Z|Exercise AIPMT/ NEET/ AIIMS Questions|80 Videos

  • IONIC EQUILIBIUM

    A2Z|Exercise Buffer Solutions|25 Videos

  • HYDROGEN

    A2Z|Exercise Section D - Chapter End Test|30 Videos

  • MOCK TEST

    A2Z|Exercise Mock Test 2|45 Videos

Similar Questions

Explore conceptually related problems

If an acidic indicator HIn ionies as HInhArrH^(+)+In^(-) . To which maximum pH value its solution has distinct colour characterstic of HIn

Calculate the pH of 10^(-8) M acid solution.

During neutralisation of an acid by a base, the end point refers for the completion of reaction. The detection of end point in acid -base neutralisation is usually made by an acid-base indicator. An acid-base indicator is itself a weak acid (Phenolphthlein) or a weak base (Mrthyl orange). At about 50% ionisation which depends on the medium, the anion furnished by an indicator (acid) or cation furnished by indicator (basic) imparts its characteristic colour to solution at point. For example phenolphthalein, the dissociation is underset("Colourless")(H In hArr H^(+))+underset("Pink")(In^(-)), K_(H In)= ([H^(+)][In^(-)])/([H In]) favoured in presence of alkali and pink colour of phenolphalein ion is noticed as soon as the medium changes to alkaline nature. The end point of acid-base neutralisation not necessarily coincides with equivalent point but it is closer and closer to equivalence point. Also at equivalence point of acid-base neutralisation pH is not necessarliy equal to 7. The dissociation constant of an acid-base indicator which furnished coloured anion is 1xx10^(-5) . The pH of solution at which indicator is 80% in dissociated form is:

Find the pH at which an acid indicator having concentration 1.0xx10^(-4)M , having dissociation of 1% shows a colour change.

During neutralisation of an acid by a base, the end point refers for the completion of reaction. The detection of end point in acid -base neutralisation is usually made by an acid-base indicator. An acid-base indicator is itself a weak acid (Phenolphthlein) or a weak base (Mrthyl orange). At about 50% ionisation which depends on the medium, the anion furnished by an indicator (acid) or cation furnished by indicator (basic) imparts its characteristic colour to solution at point. For example phenolphthalein, the dissociation is underset("Colourless")(H In hArr H^(+))+underset("Pink")(In^(-)), K_(H In)= ([H^(+)][In^(-)])/([H In]) favoured in presence of alkali and pink colour of phenolphalein ion is noticed as soon as the medium changes to alkaline nature. The end point of acid-base neutralisation not necessarily coincides with equivalent point but it is closer and closer to equivalence point. Also at equivalence point of acid-base neutralisation pH is not necessarliy equal to 7. The dissociation constant of an acid-base indicator which furnishes coloured cation is 1xx10^(-5) . The pH of solution at which indicator will furnish its colour is :

pH at which an acidic indicator with K_("in")=1xx10^(-5) changes colour when the indicator is 1xx10^(-3) M is

Calculate the pH at which an acid indicator with K_(a)=1xx10^(-5) change colour when the indicator cincentration is 1xx10^(-3)M . Also report the pH at which coloured ion is 80% present.

A2Z-IONIC EQUILIBIUM-Indicators
  1. A volume of 50.00 mL of a weak acid of unknown concentration is titrat...

    Text Solution

    |

  2. What fraction of an indicator H"in" is in the basic form at a pH of 6 ...

    Text Solution

    |

  3. Strong acids are generally used as standard solution in acid-base titr...

    Text Solution

    |

  4. At 25^(@)C pH range of phenolphthalein is 8-10. At 100^(@)C pH range o...

    Text Solution

    |

  5. An indicator is a weak acid and pH range of its colour is 3 to 5. If t...

    Text Solution

    |

  6. 100 mL of 0.02M benzoic acid (pK(a)=4.2) is titrated using 0.02 M NaOH...

    Text Solution

    |

  7. What will be the pH at the equivalence point during the titration of a...

    Text Solution

    |

  8. 20 mL of a weak monobasic acid (HA) requires 20 mL 0.2 M NaOH for comp...

    Text Solution

    |

  9. An acid-base indicator which is a weak acid has a pK(In) value =5.45. ...

    Text Solution

    |

  10. When 10ml of 0.1 M acetic acid (pK(a)=50) is titrated against 10 ml of...

    Text Solution

    |

  11. An indicator has pK(In)=5.3. In a certain titration, this indicator is...

    Text Solution

    |

  12. A certain indicator (an organic dye) has pK(a)=5. For which of the fol...

    Text Solution

    |

  13. An acid-base indicator which is a weak acid has a pK(a) value =5.5. At...

    Text Solution

    |

  14. K(b) of an acid-base indicator H In is 10^(-9). The pH at which its 10...

    Text Solution

    |

  15. A certain mixture of HCl and CH(3)-COOH is 0.1 M in each of the acids....

    Text Solution

    |

  16. A weak acid (HA) after treatment with 12 mL of 0.1 M strong base (BOH)...

    Text Solution

    |

  17. To a 200 ml of 0.1 M weak aicd HA solution 90 ml of 0.1 M solution of ...

    Text Solution

    |

  18. What is the difference in pH for 1//3 and 2//3 stages of neutralizatio...

    Text Solution

    |