Home
Class 12
CHEMISTRY
With the help of ionic equations, descri...

With the help of ionic equations, describe what happens when
(i) pH of a solution of dichromate ions is raised.
(ii) Potassium manganate is electrochemically oxidised.

Text Solution

Verified by Experts

(i) The following ionic equation describes the reaction
`Cr_(2)O_(7)^(2-)+underset("Higher pH")(2OH^(-))iff 2CrO_(4)^(2-)+H_(2)O`
When pH is raised, i.e., the solution is more basic, orange coloured ion changes to yellow coloured chromate ion.
(ii) `MnO_(4)^(2-)overset("Electrolysis")to underset("Purple")(MnO_(4)^(-)+e^(-)`
Promotional Banner

Topper's Solved these Questions

  • THE D-AND F-BLOCK ELEMENTS

    U-LIKE SERIES|Exercise LONG ANSWER QUESTIONS-I (3 marks each)|22 Videos

  • THE D-AND F-BLOCK ELEMENTS

    U-LIKE SERIES|Exercise LONG ANSWER QUESTIONS-II (5 marks each)|21 Videos

  • THE D-AND F-BLOCK ELEMENTS

    U-LIKE SERIES|Exercise VERY SHORT ANSWER QUESTIONS (1 mark each)|63 Videos

  • SURFACE CHEMISTRY

    U-LIKE SERIES|Exercise SELF ASSESSMENT TEST ( SECTION A)|7 Videos

  • THE P-BLOCK ELEMENTS

    U-LIKE SERIES|Exercise SELF ASSESSMENT TEST ( SECTION A)|7 Videos

Similar Questions

Explore conceptually related problems

What happen when a solution of potassium chromate is treated with an excess of dil. Nitic acid?

When an acidified solution of ferrous ammonium sulphate is treated with potassium permanganate solution, the ion which is oxidised is

What would happen when a solution of potassium chromate is treated with an excess of dilute nitric acid ?

Show with balanced equations what happens when the following are mixed: Aqueous solution of ferric sulphate and potassium iodide.

Describe with the help of chemical equations what happens when : (i) Lime stone is heated. (ii) water is dropped on quick lime . (iii) gypsum is heated to 473 k.

U-LIKE SERIES-THE D-AND F-BLOCK ELEMENTS -SHORT ANSWER QUESTIONS (2 marks each)
  1. When a brown compound of manganese (A) is treated with HCl it gives a ...

    Text Solution

    |

  2. Explain why (i) E^(@) for Mn^(3+)//Mn^(2+) couple is more positive t...

    Text Solution

    |

  3. With the help of ionic equations, describe what happens when (i) pH ...

    Text Solution

    |

  4. Although Zr belongs to 4d and Hf belongs to 5d transition series, but ...

    Text Solution

    |

  5. The outer electronic configurations of two transition metals are (i) 3...

    Text Solution

    |

  6. The second and third rows of transition elements resemble each other m...

    Text Solution

    |

  7. Although Cr^(3+) and Co^(2+) ions have the same number of unpaired ele...

    Text Solution

    |

  8. Although +3 oxidation state is the characteristic oxidation state of l...

    Text Solution

    |

  9. When orange solution containing CrO(7)^(2-) ion is treated with an alk...

    Text Solution

    |

  10. Explain why does the colour of KMnO(4) disappear when oxalic acid is a...

    Text Solution

    |

  11. E^(@) of Cu is + 0.34 V while that of Zn is – 0.76 V. Explain.

    Text Solution

    |

  12. The halides of transition elements become more covalent with increasin...

    Text Solution

    |

  13. Reactivity of transition elements decreases almost regularly from Sc t...

    Text Solution

    |

  14. Explain any one of the following statements : (i) The transition met...

    Text Solution

    |

  15. Answer the following questions : (i) Which element in the first seri...

    Text Solution

    |

  16. How do you account for the following: (i) all scandium salts are whi...

    Text Solution

    |

  17. Why is the +2 oxidation state of manganese quite stable, while the sam...

    Text Solution

    |

  18. While filling up of the electrons in the atomic orbitals, the 4s orbit...

    Text Solution

    |

  19. Write complete equations for (i) Oxidation of Fe^(2+) by Cr(2)O(7)^(...

    Text Solution

    |

  20. Identify the following : (i) Oxoanion of chromium which is stable in...

    Text Solution

    |