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The stability of peroxide and superoxide of alkali metals increase as we go down the group. Explain giving reason.

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प्रश्न

The stability of peroxide and superoxide of alkali metals increase as we go down the group. Explain giving reason.

दीर्घउत्तर
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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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पाठ 10: The s-block Elements - Multiple Choice Questions (Type - I) [पृष्ठ १३२]

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एनसीईआरटी एक्झांप्लर Chemistry Exemplar [English] Class 11
पाठ 10 The s-block Elements
Multiple Choice Questions (Type - I) | Q 49 | पृष्ठ १३२

संबंधित प्रश्‍न

Explain why alkali and alkaline earth metals cannot be obtained by chemical reduction methods?


Why are lithium salts commonly hydrated and those of the other alkali metal ions usually anhydrous?


Write a balanced equation for the reaction between Na2O and CO2.


Which of the alkali metal is having least melting point?


The order of decreasing ionisation enthalpy in alkali metals is ______.


Metals form basic hydroxides. Which of the following metal hydroxide is the least basic?


The solubility of metal halides depends on their nature, lattice enthalpy and hydration enthalpy of the individual ions. Amongst fluorides of alkali metals, the lowest solubility of LiF in water is due to ______.


In the synthesis of sodium carbonate, the recovery of ammonia is done by treating NH4Cl with Ca(OH)2. The by-product obtained in this process is ______.


By adding gypsum to cement


Metallic elements are described by their standard electrode potential, fusion enthalpy, atomic size, etc. The alkali metals are characterised by which of the following properties?

(i) High boiling point.

(ii) High negative standard electrode potential.

(iii) High density.

(iv) Large atomic size.


When heated in air, the alkali metals form various oxides. Mention the oxides formed by Li, Na and K.


The valence shell electronic configuration of alkali metals is ______. 


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:


Match List-I with List-II.

List-I List-II
(Metal) (Application)
(a) Cs (I) High temperature thermometer
(b) Ga (II) Water repellent sprays
(c) B (III) Photoelectric cells
(d) Si (IV) Bullet proof vest

Choose the most appropriate answer from the options given below:


A white precipitate was formed when BaCl2 was added to extract of an inorganic salt. Farther, a gas 'X' with characteristic odour was released when the formed white precipitate was dissolved in dilute HCl. The anion present in the inorganic salt is ______.


The correct order of hydration enthapies of alkali metal ions is ______.


The correct order of conductivity of ions in water is ______.


KO2 (potassium super oxide) is used in oxygen cylinders in space and submarines because it ______.


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