Question

Slaked lime and chlorine react to produce:
a.) Quick lime
b.) $CaCl_{ 2 }$
c.) $CaOCl_{ 2 }$
d.) A mixture of $CaCl_{ 2 }$ and $Ca(OCl_{ 2 })$

Answer 1

Hint: To answer this question, you should know about slaked lime. Slaked lime is the hydrated form of the compound calcium oxide. Now try to recall its reaction with chlorine and answer this question accordingly.

Complete step by step answer:

We should know that lime is the most widely used reagent in water treatment applications. It is supplied in two forms -
The first one is, quick lime (CaO) and the second one is slaked (or hydrated) lime ($Ca(OH)_{ 2 }$)
When chlorine gas reacts with slaked lime it forms calcium hypochlorite along with water and calcium chloride. Calcium hypochlorite is an aqueous form due to high solubility with water and the $CaCl_{ 2 }$ is precipitated in the form of sludge.
$2Ca(OH)_{ 2 }(aq)\quad +\quad 2Cl_{ 2 }(g)\quad \rightarrow \quad Ca(OCl)_{ 2 }(aq)\quad +\quad CaCl_{ 2 }(ppt)\quad +\quad 2H_{ 2 }O$
Calcium oxychloride ($CaOCl_{ 2 }$), in common language, is called bleaching powder too.
In $CaOCl_{ 2 }$ structure, it has Cl with 2 different oxidation numbers -1 and +1.

Therefore, we can say that the correct answer to this question is option D.

Note: We must know that the often used bleaching powder is $CaOCl_{ 2 }$. $CaOCl_{ 2 }$ can be seen as a 1:1 combination of $CaCl_{ 2 }$ and $Ca(OCl)_{ 2 }$. It has the ability to bleach and bleaching powder is sometimes called chloride of lime.