Advertisements
Advertisements
प्रश्न
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
Advertisements
उत्तर
(B) Babbitt metal
APPEARS IN
संबंधित प्रश्न
What are interstitial compounds?
Calculate magnetic moment of `Fe_((aq))^(2+) ion (Z=26).`
The elements of 3d transition series are given as: Sc Ti V Cr Mn Fe Co
Answer the following: Write the element which shows maximum number of oxidation states. Give reason.
Explain why Cu+ ion is not stable in aqueous solutions?
Predict which of the following will be coloured in the aqueous solution?
Ti3+, V3+, Cu+, Sc3+, Mn2+, Fe3+ and Co2+. Give reasons for each.
What is meant by ‘disproportionation’?
What are alloys?
Comment on the statement that elements of the first transition series possess many properties different from those of heavier transition elements.
How would you account for the following?
Transition metals and their compounds act as catalysts.
Complete and balance the following chemical equations
`Fe^(2+) + MnO_4^(-) + H^+ ->`
Give reasons Iron has the higher enthalpy of atomization than that of copper.
Why do transition metal ions possess a great tendency to form complexes?
Explain why Mn2+ is more stable than Fe2+ towards oxidation to +3 state. (At. no. of Mn = 25, Fe = 26)
Interstitial compounds are formed when small atoms are trapped inside the crystal lattice of metals. Which of the following is not the characteristic property of interstitial compounds?
Which of the following will not act as oxidising agents?
(i) \[\ce{CrO3}\]
(ii) \[\ce{MoO3}\]
(iii) \[\ce{WO3}\]
(iv) \[\ce{CrO^{2-}4}\]
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.
Match the solutions given in Column I and the colours given in Column II.
| Column I (Aqueous solution of salt) |
Column II (Colour) |
| (i) \[\ce{FeSO2.7H2O}\] | (a) Green |
| (ii) \[\ce{NiCl2.4H2O}\] | (b) Light pink |
| (iii) \[\ce{MnCl2.4H2O}\] | (c) Blue |
| (iv) \[\ce{CoC12,6H2O}\] | (d) Pale green |
| (v) \[\ce{Cu2 Cl2}\] | (e) Pink |
| (f) Colourless |
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?
Account for the following:
In case of transition elements, ions of the same charge in a given series show progressive decrease in radius with increasing atomic number.
A complex in which dsp2 hybridisation takes place is ______.
The electrode potential of M2+/M of 3d-series elements shows the positive value for ______.
Write the number of unpaired electrons in Cr3+.
(Atomic number of Cr = 24)
Give two similarities in the properties of Sc and Zn.
Explain the use of different transition metals as catalysts.
Give a reason for the following.
Some transition metals and their compounds get attracted towards the magnetic field.
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:
