Home
Class 11
CHEMISTRY
The s-block elements are characterised b...

The s-block elements are characterised by their larger atomic sizes, lower ionisation enthalpies, invariable +1 oxidation state and solubilities of their oxosalts. In the light of these features describe the nature of their oxides, halides and oxosalts.

Text Solution

Verified by Experts

Due to low ionisation energy and large atomic size, alkali metals form cation readily and so their compounds are ionic. Oxides Due to `+1` oxidation state, alkali metals form normal oxides of general formula `M_(2)O`. Only Li forms normal oxide `Li_(2)O` when heated in air. Other form peroxide and superoxide. Oxides of alkali metals are strongly basic and are soluble in water. The basix character of oxide increases gradually from `Li_(2)O` and `Cs_(2)O` due to increased ionic character. Halides Except lithium halides all other alkali metal halides are ionic. Due to high polarising power of `Li^(+)`, Lithium halide is covalent in nature. Due to +1 oxidation states alkali metal halides halides have general formula `MX`. Low ionisation enthalpy allows formation of ionic halides. Oxo salts All alkali metals form solid carbonates of general formula `M_(2)CO_(3)`. Carbonates are stable except `Li_(2)CO_(3)` due to high polarising capacity of `Li^(+)` which is unstable and decomposes. All the alkali metals (except Li) form solid bicarbonates `MHCO_(3)`. All alkali metals form nitrates having formula `MNO_(3)`. They are colourless, water soluble, electrovalent compounds.
Promotional Banner

Topper's Solved these Questions

  • THE S-BLOCK ELEMENTS

    NCERT EXEMPLAR|Exercise Assertion and Reason|2 Videos

  • THE P-BLOCK ELEMENTS

    NCERT EXEMPLAR|Exercise Long Answer|10 Videos

  • THERMODYNAMICS

    NCERT EXEMPLAR|Exercise Multiple choice questions|62 Videos

Similar Questions

Explore conceptually related problems

Which element(s) of d-block have full d^(10) configuration in their ground state as well as in their common oxidation states?

The transition element ( with few exceptions ) show a large number of oxidation states . The various oxidation states are related to the electronic configuration of their atoms. The variable oxidation states of a transition metal is due to the involvement of (n-1)d and outer ns electrons . For the first five elements of 3d transition series , the minimum oxidation state is equal to the number of electrons in 4s shell and the maximum oxidation state is equal to the sum of 4s and 3d electrons. The relative stability of various oxidation states of a given element can be explained on the basis of stability of d^(0),d^(5) and d^(10) configuration . In 3d series, the maximum oxidation state is shown by

The transition element ( with few exceptions ) show a large number of oxidation states . The various oxidation states are related to the electronic configuration of their atoms. The variable oxidation states of a transition metal is due to the involvement of (n-1)d and outer ns electrons . For the first five elements of 3d transition series , the minimum oxidation state is equal to the number of electrons in 4s shell and the maximum oxidation state is equal to the sum of 4s and 3d electrons. The relative stability of various oxidation states of a given element can be explained on the basis of stability of d^(0),d^(5) and d^(10) configuration . Identify the correct statement

The transition element ( with few exceptions ) show a large number of oxidation states . The various oxidation states are related to the electronic configuration of their atoms. The variable oxidation states of a transition metal is due to the involvement of (n-1)d and outer ns electrons . For the first five elements of 3d transition series , the minimum oxidation state is equal to the number of electrons in 4s shell and the maximum oxidation state is equal to the sum of 4s and 3d electrons. The relative stability of various oxidation states of a given element can be explained on the basis of stability of d^(0),d^(5) and d^(10) configuration . In which of the following pairs , the first species is more stable than second one

Knowledge Check

  • 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 ?

    A
    High boiling point
    B
    High negative standard electrode potential
    C
    High density
    D
    Large atomic size

  • Which element(s) of d-block have full d^(10) configuration in their ground state as well as in their common oxidation states?

    A
    `Zn`
    B
    `Cd`
    C
    `Hg`
    D
    `Ag`

  • Transition metals combine with halogens at high temperature to form compounds called halides. On account of high activation energy , the reactions require high temperature to start, but once the the reaction is started , the heat of reaction is sufficient to maintain the continuity . Metals in higher oxidation state form flourides as it is the most electronegative element . Flourides are ionic in nature . The chlorides , bromides and iodides have ionic as well as covalent character . Halides of metals is higher oxidation states are relatively unstable and hydrolysed very easily . DeltaH_(f) is negative for

    A
    Flourides
    B
    Bromides
    C
    Iodides
    D
    All of these