Tag: some useful compounds in everyday life

Slaked lime reacts with chlorine to give bleaching powder.

Bleaching powder is known as calcium hypochlorite. It is marketed as bleach powder. It is white solid although commercial samples appear yellow. It is not highly soluble in water and is used in soft to medium hard water. It has two forms dry and hydrated.

Baking soda is commonly known as sodium bicarbonate $ NaHC{ O } _{ 3 } $ used for cooking purposes.

Bleaching action takes place due to the hypochlorite radical [$ClO^{-}$].

The reaction of $NaCl$ and $CaCO _3$ gives sodium carbonate. But this reaction cannot be used for the manufacture of washing soda since it is a reversible reaction.

$2NaCl+CaCO _3\rightleftharpoons Na _2CO _3+CaCl _2$.

Hence the given statement is True.

Bleaching powder on reaction with cold water form milky solution of calcium hydroxide. 

$CaOCl _2+H _2O\rightarrow Ca(OH) _2+Cl _2$

Thus because of the lime present in it, it gives a milky solution when dissolved in water.

$CoCl _2$ is used as catalyst in the decomposition of bleaching powder.

When exposed to air, bleaching powder gives a smell of chlorine. This is because bleaching powder reacts with carbon dioxide from the atmosphere to produce calcium carbonate and chlorine.

In bleaching powder, $Ca(OCl)Cl$, the two $Cl$ atoms are in different oxidation states i.e., one $Cl^–$ having oxidation number of –1 and the other as $OCl^–$ having oxidation number of +1.