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प्रश्न
When heated in air, the alkali metals form various oxides. Mention the oxides formed by Li, Na and K.
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उत्तर
Alkali metals forms oxide when reacted with air. Lithium forms monoxide, sodium forms peroxide and potassium forms superoxide.
\[\ce{4Li + O2 -> 2Li2O}\]
\[\ce{Na + O2 -> Na2O2}\]
\[\ce{L + O2 -> KO2}\]
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संबंधित प्रश्न
What are the common chemical features of alkali metals?
Why are potassium and cesium, rather than lithium used in photoelectric cells?
When an alkali metal dissolves in liquid ammonia the solution can acquire different colours. Explain the reasons for this type of colour change.
Write a balanced equation for the reaction between KO2 and water.
Write a balanced equation for the reaction between Na2O and CO2.
Which of the alkali metal is having least melting point?
For alkali metals, which one of the following trends is incorrect?
Which of the following statements is incorrect?
What are the common physical features of alkali metals?
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 ______.
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.
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?
When a metal of group 1 was dissolved in liquid ammonia, the following observations were obtained:
(i) Blue solution was obtained initially.
(ii) On concentrating the solution, blue colour changed to bronze colour.
How do you account for the blue colour of the solution? Give the name of the product formed on keeping the solution for some time.
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 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:
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 ______.
