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प्रश्न
Why do interstitial compounds have higher melting points than corresponding pure metals?
उत्तर
The melting points of interstitial compounds are higher than those of pure metals because of bonding between the metal and the non-metal, which is stronger than metal–metal bonding.
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संबंधित प्रश्न
The elements of 3d transition series are given as: Sc Ti V Cr Mn Fe Co
Answer the following: Which element is a strong oxidising agent in +3 oxidation state and why?
Write down the number of 3d electrons in the following ion:
Cu2+
Indicate how would you expect the five 3d orbitals to be occupied for this hydrated ions (octahedral).
What can be inferred from the magnetic moment value of the following complex species?
| Example | Magnetic Moment (BM) |
| K2[MnCl4] | 5.9 |
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
Why does the density of transition elements increase from Titanium to Copper? (at. no. Ti = 22,
Cu = 29)
The paramagnetic character in-3d-transition series elements increases-: up to Mn and then decreases.
Why do transition elements show variable oxidation states ? In 3d series (Sc to Zn), which elements shows the maximum number of oxidation state and why ?
How is potassium dichromate prepared from chrome iron ore?
Why do transition metals exhibit higher enthalpy of atomization?
Two metallic elements A and B have the following standard oxidation potentials: A = 0·40v B = - 0·80v. What would you expect if element A was added to an aqueous salt solution of element B? Give a reason for your answer.
Give reasons for the following:
The transition metals generally form coloured compounds.
Transition elements show magnetic moment due to spin and orbital motion of electrons. Which of the following metallic ions have almost same spin only magnetic moment?
(i) \[\ce{Co^{2+}}\]
(ii) \[\ce{Cr^{2+}}\]
(iii) \[\ce{Mn^{2+}}\]
(iv) \[\ce{Cr^{3+}}\]
Why EΘ values for Mn, Ni and Zn are more negative than expected?
Although fluorine is more electronegative than oxygen, but the ability of oxygen to stabilise higher oxidation states exceeds that of fluorine. Why?
Assertion: \[\ce{Cu^2+}\] iodide is not known.
Reason: \[\ce{Cu^2+}\] oxidises \[\ce{I^-}\] to iodine.
Assertion: \[\ce{Cu}\] cannot liberate hydrogen from acids.
Reason: Because it has positive electrode potential.
Answer the following question:
Which element of the first transition series has highest third ionisation enthalpy?
Catalytic hydrogenation of benzene gives
Which of the following maxm magnetic moment?
On adding NaOH, solution to the aqueous solution of K2CrO7 the colour of the solution changes from
Which of the following transition metal is not coloured?
The number of terminal oxygen atoms present in the product B obtained from the following reactions is:
\[\ce{FeCr2O4 + Na2CO3 + O2 -> A + Fe2O3 + CO2}\]
\[\ce{A + H^+ -> B + H2O + Na^+}\]
The oxidation state of Fe in [Fe(CO)5] is ______.
Which of the following characteristics of transition metals is associated with their catalytic activity?
Which of the following transition metals shows +1 and +2 oxidation states?
A transition element X has an electronic configuration [Ar]4s23d3. Predict its likely oxidation states.
Account for the following:
Eu2+ with electronic configuration [Xe]4f76s2 is a strong reducing agent.
Compare the general characteristics of the first series of the transition metals with those of the second and third series metals in the respective vertical columns. Give special emphasis on the following point:
Atomic sizes
