Elements of Groups 16, 17 and 18 — Chemistry STD 12 Science — Question
Maharashtra BoardEnglish MediumSTD 12 ScienceChemistryElements of Groups 16, 17 and 183 Marks
Question
What is the action of heat on $KClO _3$ ?
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Answer
Laboratory methods: (i) By heating chlorates, nitrates and permanganates. Potassium chlorate in the presence of manganese dioxide on heating decomposes to form potassium chloride and oxygen. $2 KClO _3 \frac{\Delta}{ MnO _2} 2 KCl +3 O _{2( g )}$
(ii) By the thermal decomposition of metal oxides. \9\begin{aligned} & 2 Ag _2 O _{( s )} \xrightarrow{\text { heat }} 4 Ag + O _{2( g )} \\ & 2 HgO _{( s )} \xrightarrow{\text { heat }} 2 Hg + O _{2( g )} \\ & 2 PbO _{2( s )} \xrightarrow{\text { heat }} 2 PbO _{( s )}+ O _{2( g )} \end{aligned}$
(iii) By the thermal decomposition of hydrogen peroxide : The thermal decomposition of hydrogen peroxide in the presence of finely divided metal and manganese dioxide used as catalyst gives oxygen. $2 H _2 O _{2 \text { (aq) }} \frac{\text { heat }}{ MnO _2} 2 H _2 O _{(1)}+ O _{2( g )}$
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