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प्रश्न
What are alloys?
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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
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.
The elements of 3d transition series are given as: Sc Ti V Cr Mn Fe Co
Answer the following: Which element shows only +3 oxidation state?
Which of the d-block elements may not be regarded as the transition elements?
Calculate the number of unpaired electrons in the following gaseous ions:
Mn3+, Cr3+, V3+ and Ti3+. Which one of these is the most stable in an aqueous solution?
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?
Why is \[\ce{HCl}\] not used to make the medium acidic in oxidation reactions of \[\ce{KMnO4}\] in acidic medium?
Transition elements form binary compounds with halogens. Which of the following elements will form \[\ce{MF3}\] type compounds?
(i) \[\ce{Cr}\]
(ii) \[\ce{Co}\]
(iii) \[\ce{Cu}\]
(iv) \[\ce{Ni}\]
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.
When an oxide of manganese (A) is fused with KOH in the presence of an oxidising agent and dissolved in water, it gives a dark green solution of compound (B). Compound (B) disproportionates in neutral or acidic solution to give purple compound (C). An alkaline solution of compound (C) oxidises potassium iodide solution to a compound (D) and compound (A) is also formed. Identify compounds A to D and also explain the reactions involved.
If enthalpies of formation of C2H4(g), CO2(g) and H2O(l) at 25°C and 1 atm pressure are 52, – 394 and – 286 kJ/mol respectively, the change in ethalpy for combustion of C2H4 is equal to
The spin magnetic moment of cobalt in the compound Hg [Co(SCN)4] is:-
Sodium this sulphate is used in photography because of its:-
Passing H2S gas into a mixture of Mn2+ and Ni2+, Cu2+, ions in an acidified aqueous solution precipitates.
Give reasons for the following statement:
Transition metals and most of their compounds show paramagnetic behaviour.
Account for the following:
Sc3+ is colourless whereas Ti3+ is coloured in an aqueous solution.
A transition element X has an electronic configuration [Ar]4s23d3. Predict its likely oxidation states.
Give two similarities in the properties of Sc and Zn.
Give a reason for the following:
Zinc, cadmium and mercury are considered as d-block elements but not regarded as transition elements.
