Question

Bleaching powder and bleach solutions are produced on a large scale and are used in several household products. The effectiveness of the bleach solution is often measured by iodometry. Bleaching powder contains a salt of an oxoacid as one of its components. The anhydride of that oxoacid is:
(A.) ${ Cl }_{ 2 }{ O }$
(B.) ${ Cl }_{ 2 }{ O }_{ 7 }$
(C.) ${ Cl }{ O }_{ 2 }$
(D.) ${ Cl }_{ 2 }{ O }_{ 6 }$
(E.) ${ Cl }_{ 2 }{ O }_{ 3 }$
(F.) ${ Cl }_{ 2 }{ O }_{ 5 }$
(G.) ${ Cl }_{ 3 }{ O }_{ 9 }$
(H.) ${ Cl }_{ 3 }{ O }_{ 5 }$

Answer 1

Hint: There is only one correct answer among these eight options. First, recall the formula for bleaching powder and then try to find its anhydride. This anhydride would be your answer.

Complete step by step solution:
You should know that Bleaching powder is a pale yellowish powder existing with a strong smell of chlorine.
It is soluble in water but due to the presence of impurities, you will not observe a clear solution. Its chemical formula is $Ca(OCl)_{ 2 }$ with its chemical name as Calcium hypochlorite.
Both Bleaching powder and bleach solution are the same.
Here, $Ca(OCl)_{ 2 }$ is a salt of HOCl.
${ Cl }_{ 2 }{ O }$ is the anhydride of HOCl.
Anhydride, any chemical compound obtained, by the elimination of water from another compound.
We can also write the chemical equation:

$Cl_{ 2 }O+H_{ 2 }O\rightarrow 2HOCl$

Therefore, we can conclude that the correct answer to this question is option A.


Note: We should also know that Bleaching powder is made by the action of chlorine gas on calcium hydroxide:

$2Ca(OH)_{ 2 }+2Cl_{ 2 }\rightarrow Ca(OCl)_{ 2 }+CaCl_{ 2 }+2H_{ 2 }O$

Remember that the oxidizing bleaching agents that do not contain chlorine are usually based on peroxides such as hydrogen peroxide, sodium percarbonate, and sodium perborate.