The order of melting point of chlorides of alkali metals is -?a)LiCl &...
From Fajan rule
M.P. a thermal stability a Lattice energy
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The order of melting point of chlorides of alkali metals is -?a)LiCl &...
The correct order of melting point of chlorides of alkali metals is c) NaCl KCl CsCl LiCl.
Explanation:
- Alkali metals are the elements belonging to Group 1 of the periodic table. These elements include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr).
- The melting point of a substance is the temperature at which it changes from a solid to a liquid state. It is a measure of the strength of the forces holding the particles together in the solid state.
- In the case of alkali metal chlorides, the melting point depends on the size and charge of the alkali metal cation and the chloride anion.
- The size of the alkali metal cation increases down the group, as the atomic radius increases.
- The charge of the alkali metal cation remains the same (+1) for all the elements in the group.
- The chloride anion is the same for all the alkali metal chlorides (-1 charge).
- The strength of the forces holding the particles together in the solid state depends on the size and charge of the ions.
- As the size of the alkali metal cation increases, the strength of the forces holding the particles together decreases. This is because larger ions have a weaker attractive force between them.
- Therefore, the alkali metal chlorides with larger cations have lower melting points.
- Among the given options, the correct order of melting point of chlorides of alkali metals is c) NaCl KCl CsCl LiCl.
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