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प्रश्न
The compounds of \[\ce{Ti^4+}\] ions are colourless due to ______.
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उत्तर
The electronics configuration of
\[\ce{Ti = [Ar]}\]3d24s2 and
\[\ce{Ti^4+ = [Ar]}\]3d0
Due to the absence of unpaired electrons in 3d subshell, d-d transition is not possible. Therefore, \[\ce{Ti^4+}\] ions do not adsorb the radiation in the visible region. Hence, compounds of \[\ce{Ti^4+}\] ions are colourless.
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संबंधित प्रश्न
Account for the following:
E° value for the Mn3+/Mn2+ couple is much more positive than that for Cr3+/Cr2+.
What may be the stable oxidation state of the transition element with the following d electron configuration in the ground state of its atom?
3d3
In what way is the electronic configuration of the transition elements different from that of the non-transition elements?
What is meant by ‘disproportionation’?
Use Hund’s rule to derive the electronic configuration of Ce3+ ion and calculate its magnetic moment on the basis of ‘spin-only’ formula.
Comment on the statement that elements of the first transition series possess many properties different from those of heavier transition elements.
Write the factors which are related to the colour of transition metal ions.
How would you account for the following?
Zr (Z = 40) and Hf (Z = 72) have almost identical radii.
How is potassium dichromate prepared from chrome iron ore?
Explain why transition metals and their compounds act as a catalyst.
Which is the most stable oxidation state of iron?
In lake test for Al3+ ions, there is the formation of coloured ‘floating lake’. It is due to ______.
Although fluorine is more electronegative than oxygen, but the ability of oxygen to stabilise higher oxidation states exceeds that of fluorine. 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?
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?
Read the passage given below and answer the following question.
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Are there nuclear reactions going on in our bodies? There are nuclear reactions constantly occurring in our bodies, but there are very few of them compared to the chemical reactions, and they do not affect our bodies much. All of the physical processes that take place to keep a human body running are chemical processes. Nuclear reactions can lead to chemical damage, which the body may notice and try to fix. The nuclear reaction occurring in our bodies is radioactive decay. This is the change of a less stable nucleus to a more stable nucleus. Every atom has either a stable nucleus or an unstable nucleus, depending on how big it is and on the ratio of protons to neutrons. The ratio of neutrons to protons in a stable nucleus is thus around 1 : 1 for small nuclei (Z < 20). Nuclei with too many neutrons, too few neutrons, or that are simply too big are unstable. They eventually transform to a stable form through radioactive decay. Wherever there are atoms with unstable nuclei (radioactive atoms), there are nuclear reactions occurring naturally. The interesting thing is that there are small amounts of radioactive atoms everywhere: in your chair, in the ground, in the food you eat, and yes, in your body. The most common natural radioactive isotopes in humans are carbon-14 and potassium-40. Chemically, these isotopes behave exactly like stable carbon and potassium. For this reason, the body uses carbon-14 and potassium-40 just like it does normal carbon and potassium; building them into the different parts of the cells, without knowing that they are radioactive. In time, carbon-14 atoms decay to stable nitrogen atoms and potassium-40 atoms decay to stable calcium atoms. Chemicals in the body that relied on having a carbon-14 atom or potassium-40 atom in a certain spot will suddenly have a nitrogen or calcium atom. Such a change damages the chemical. Normally, such changes are so rare, that the body can repair the damage or filter away the damaged chemicals. The natural occurrence of carbon-14 decay in the body is the core principle behind carbon dating. As long as a person is alive and still eating, every carbon-14 atom that decays into a nitrogen atom is replaced on average with a new carbon-14 atom. But once a person dies, he stops replacing the decaying carbon-14 atoms. Slowly the carbon-14 atoms decay to nitrogen without being replaced, so that there is less and less carbon-14 in a dead body. The rate at which carbon-14 decays is constant and follows first order kinetics. It has a half-life of nearly 6000 years, so by measuring the relative amount of carbon-14 in a bone, archeologists can calculate when the person died. All living organisms consume carbon, so carbon dating can be used to date any living organism, and any object made from a living organism. Bones, wood, leather, and even paper can be accurately dated, as long as they first existed within the last 60,000 years. This is all because of the fact that nuclear reactions naturally occur in living organisms. |
Which are the two most common radioactive decays happening in human body?
On adding NaOH, solution to the aqueous solution of K2CrO7 the colour of the solution changes from
Which of the following ions will exhibit colour in aqueous solution?
The electrode potential of M2+/M of 3d-series elements shows the positive value for ______.
Which of the following ions acts as a typical transition metal ion?
Assertion (A): Transition metals have high enthalpy of atomisation.
Reason (R): Greater number of unpaired electrons in transition metals results in weak metallic bonding.
Assertion (A): Transition metals show their highest oxidation state with oxygen.
Reason (R): The ability of oxygen to form multiple bonds to metals.
Write the number of unpaired electrons in Cr3+.
(Atomic number of Cr = 24)
Account for the following:
Copper has an exceptionally positive `"E"_("M"^(2+)//"M")^0` value.
Describe the oxidising action of potassium dichromate and write the ionic equation for its reaction with iron (II) solution.
Describe the oxidising action of potassium dichromate and write the ionic equation for its reaction with H2S.
Match List-I with List-II.
| List-I | List-II |
| A. Haber process | I. Fe catalyst |
| B. Wacker oxidation | II. PdCl2 |
| C. Wilkinson catalyst | III. [(PPh3)3RhCl] |
| D. Ziegler catalyst | IV. TiCl4 with Al(CH3)3 |
Choose the correct answer from the options given below:
The E° value for the Mn2+/Mn2+ couple is more positive than that of Cr3+/Cr2+ or Fe3+/Fe2+ due to the change of:
