Advertisements
Advertisements
प्रश्न
What are alloys?
Advertisements
उत्तर
An alloy is a blend of metals prepared by mixing the components. Alloys may be homogeneous solid solutions in which the atoms of one metal are distributed randomly among the atoms of the other.
संबंधित प्रश्न
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
Complete and balance the following chemical equations
`MnO_4^(-) + H_2O + I^(-) ->`
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 ?
\[\ce{KMnO4}\] acts as an oxidising agent in acidic medium. The number of moles of \[\ce{KMnO4}\] that will be needed to react with one mole of sulphide ions in acidic solution is ______.
Why EΘ values for Mn, Ni and Zn are more negative than expected?
Assertion: Separation of \[\ce{Zr}\] and \[\ce{Hf}\] is difficult.
Reason: Because \[\ce{Zr}\] and \[\ce{Hf}\] lie in the same group of the periodic table.
When a chromite ore (A) is fused with sodium carbonate in free excess of air and the product is dissolved in water, a yellow solution of compound (B) is obtained. After treatment of this yellow solution with sulphuric acid, compound (C) can be crystallised from the solution. When compound (C) is treated with KCl, orange crystals of compound (D) crystallise out. Identify A to D and also explain the reactions.
Answer the following question:
Which element of the first transition series has lowest enthalpy of atomisation?
Mention any three processes where transition metals act as catalysts.
Passing H2S gas into a mixture of Mn2+ and Ni2+, Cu2+, ions in an acidified aqueous solution precipitates.
The basic character of transition metals monoxide follow the order.
Which of the following ions has the maximum magnetic moment?
Match List - I with List - II.
| List - I | List - II | ||
| (A) | [Fe(CN)6]3− | (i) | 5.92 BM |
| (B) | [Fe(H2O)6]3+ | (ii) | 0 BM |
| (C) | [Fe(CN)6]4− | (iii) | 4.90 BM |
| (D) | [Fe(H2O)6]2+ | (iv) | 1.73 BM |
Choose the correct answer from the options given below.
Account for the following:
Transition metals form alloys.
In the ground state of atomic Fe (Z = 26), the spin-only magnetic moment is ______ × 10-1 BM.
(Round off to the nearest integer).
[Given: `sqrt3 = 1.73, sqrt2 = 1.41`]
What is the oxidation state of chromium in chromate ion and dichromate ion?
Explain the use of different transition metals as catalysts.
Give a reason for the following:
Transition metals possess a great tendency to form complex compounds.
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
‘Spin only’ magnetic moment is the same for which of the following ions?
- Ti3+
- Cr2+
- Mn2+
- Fe2+
- Sc3+
Choose the most appropriate answer from the options given below:
