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प्रश्न
What is meant by ‘disproportionation’?
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उत्तर
The oxidation and reduction of a substance at the same time as a result of a chemical reaction is called disproportionation.
संबंधित प्रश्न
Explain briefly how +2 state becomes more and more stable in the first half of the first row transition elements with increasing atomic number?
What may be the stable oxidation state of the transition element with the following d electron configurations in the ground state of its atom?
3d3
How would you account for the following:
The d1 configuration is very unstable in ions.
An antifriction alloy made up of antimony with tin and copper, which is extensively used in machine bearings is called _______.
(A) Duralumin
(B) Babbitt metal
(C) Spiegeleisen
(D) Amalgam
Following are the transition metal ions of 3d series:
Ti4+, V2+, Mn3+, Cr3+
(Atomic numbers: Ti = 22, V = 23, Mn = 25, Cr = 24)
Answer the following:
1) Which ion is most stable in an aqueous solution and why?
2) Which ion is a strong oxidising agent and why?
3) Which ion is colourless and why?
The paramagnetic character in the 3d-transition series elements increases up to Mn and then decreases.
Account for the following :
Ti4+ is colourless whereas V4+ is coloured in an aqueous solutions.
Explain why Mn2+ is more stable than Fe2+ towards oxidation to +3 state. (At. no. of Mn = 25, Fe = 26)
Electronic configuration of Mn2+ is ____________.
Metallic radii of some transition elements are given below. Which of these elements will have highest density?
| Element | \[\ce{Fe}\] | \[\ce{Co}\] | \[\ce{Ni}\] | \[\ce{Cu}\] |
| Metallic radii/pm | 126 | 125 | 125 | 128 |
Which of the following statements is not correct?
Transition elements show high melting points. Why?
When a brown compound of manganese (A) is treated with \[\ce{HCl}\] it gives a gas (B). The gas taken in excess, reacts with \[\ce{NH3}\] to give an explosive compound (C). Identify compounds A, B and C.
Ionisation enthalpies of Ce, Pr and Nd are higher than Th, Pa and U. Why?
The second and third rows of transition elements resemble each other much more than they resemble the first row. Explain why?
The halides of transition elements become more covalent with increasing oxidation state of the metal. Why?
Reactivity of transition elements decreases almost regularly from Sc to Cu. Explain.
It has been observed that first ionization energy of 5 d series of transition elements are higher than that of 3d and 4d series, explain why?
The value of Δ0 for \[\ce{RhCl^{3-}6}\] is 243 KJ/mol which wavelength of light will promote an electron from. The colour of the complex is ______.
Write the number of unpaired electrons in Cr3+.
(Atomic number of Cr = 24)
