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The S-Block Elements

Question
CBSEENCH11007166
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What is the effect of heat on the following compounds? (Write equations for the reactions):
(i) Calcium Carbonate
(ii) Magnesium chloride hexahydrate
(iii) Gypsum
(iv) Magnesium sulphate heptahydrate

Solution
(i) Calcium carbonate on heating decomposes to produce calcium oxide (quick lime) and carbon dioxide.
CaCO subscript 3 space rightwards arrow with 1070 space minus 1270 straight K on top space CaO space plus space CO subscript 2
(ii)  MgCl2.6H2O, on heating undergoes hydrolysis by its own water of crystallisation to give magnesium oxide and hyrogen chloride.
                  MgCl subscript 2. space end subscript 6 straight H subscript 2 straight O space rightwards arrow with Heat on top space MgO space plus space 2 HCl space plus space 5 straight H subscript 2 straight O
(iii) On heating to 390K, it forms a compound having the composition CaSO subscript 4. space 1 half straight H subscript 2 straight O left parenthesis known space as space Plaster space of space Paris right parenthesis which on heating above 473 K, changes into anhydrous calcium sulphate. 
               CaSO subscript 4. space 2 straight H subscript 2 straight O space rightwards arrow with 390 space straight K on top space CaSO subscript 4. space 1 half straight H subscript 2 straight O space space rightwards arrow from 473 space straight K to above of space CaSO subscript 4
(iv) On heating to 423 K, it changes into monohydrate which on further heating to 473K, forms anhydrous salt. 
          MgSO subscript 4. space 7 straight H subscript 2 straight O space space rightwards arrow with 423 space straight K on top space MgSO subscript 4. space straight H subscript 2 straight O space rightwards arrow with 473 space straight K on top space MgSO subscript 4 space plus space straight H subscript 2 straight O
Anhydrous salt on further heating, forms MgO.
              MgSO subscript 4 space rightwards arrow with Heat on top space MgO space plus space SO subscript 3

Some More Questions From The s-Block Elements Chapter

In aqueous solution, Li+ ion has lowest mobility. Why?

Lithium has highest ionisation energy in group 1 elements, yet it is strongest reducing agent. Comment.

The softness of group 1 elements increases down the group with increasing atomic number. Give reason. 

Which is the most reactive alkali metal and why?

Why alkali metals do not form M2+ ions?

Name the radio active element in group 1. How does it resemble with the remaining elements of the group?

Why alkali metals are normally kept in kerosene oil?

Why lithium cannot be stored in kerosene?

Why does lithium form complexes?

Why are alkali metal ions diamagnetic and colourless?

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