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प्रश्न
The stability of peroxide and superoxide of alkali metals increase as we go down the group. Explain giving reason.
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उत्तर
As the size of metal ions increases, the stability of peroxides and superoxides increases. Peroxide and superoxide ions combine with a large size of alkali metals. Lithium forms monoxide, sodium forms peroxide and potassium, rubidium and caesium forms superoxide.
\[\ce{Li + O2 -> Li2O}\]
\[\ce{Na + O2 -> Na2O2}\]
\[\ce{K + O2 -> KO2}\]
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संबंधित प्रश्न
What are the common chemical features of alkali metals?
Why are alkali metals not found in nature?
Explain why alkali and alkaline earth metals cannot be obtained by chemical reduction methods?
Why are potassium and cesium, rather than lithium used in photoelectric cells?
Why are lithium salts commonly hydrated and those of the other alkali metal ions usually anhydrous?
Write a balanced equation for the reaction between KO2 and water.
Write a balanced equation for the reaction between Na2O and CO2.
Which one of the following alkali metals gives hydrated salts?
For alkali metals, which one of the following trends is incorrect?
Which of the following statements is incorrect?
The alkali metals are low melting. Which of the following alkali metal is expected to melt if the room temperature rises to 30°C?
The order of decreasing ionisation enthalpy in alkali metals is ______.
Choose the correct statements from the following.
(i) Beryllium is not readily attacked by acids because of the presence of an oxide film on the surface of the metal.
(ii) Beryllium sulphate is readily soluble in water as the greater hydration enthalpy of Be2+ overcomes the lattice enthalpy factor.
(iii) Beryllium exhibits coordination number more than four.
(iv) Beryllium oxide is purely acidic in nature.
When heated in air, the alkali metals form various oxides. Mention the oxides formed by Li, Na and K.
Write Lewis strucure of \[\ce{O^{-}2}\] ion and find out oxidation state of each oxygen atom? What is the average oxidation state of oxygen in this ion?
Ions of an element of group 1 participate in the transmission of nerve signals and transport of sugars and aminoacids into cells. This element imparts yellow colour to the flame in flame test and forms an oxide and a peroxide with oxygen. Identify the element and write chemical reaction to show the formation of its peroxide. Why does the element impart colour to the flame?
The ease of absorption of the hydrated alkali metals ions in an ion-exchange resin follows the order:
Match List-I with List-II.
| List-I | List-II |
| (Metal) | (Emitted light wavelength (nm)) |
| (a) Li | (I) 780.0 |
| (b) Na | (II) 455.5 |
| (c) Rb | (III) 670.8 |
| (d) Cs | (IV) 589.2 |
Choose the most appropriate answer from the options given below:
The correct order of conductivity of ions in water is ______.
