Question
Write one equation each for decomposition reactions where energy is supplied in the form of heat, light or electricity.
✓
Answer
When calcium carbonate is heated, it decomposes to give calcium oxide and carbon dioxide:$\text{CaCO}_3 \xrightarrow{\ \ \ \ \ \ \ \Delta\ \ \ \ \ \ \ \ \ \ }\ \ \ \text{CaO}\ \ \ \ +\ \ \ \text{CO}_2\\ \text{Calcium}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \\\text{Carbonate}\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ $
When electric current is passed through acidified water, it decomposes to give hydrogen gas and oxygen gas. This reaction can be represented as:$2\text{H}_2\text{O}\ (\text{l})\ \ \ \xrightarrow{\text{Electricity}}\ \ \ 2\text{H}_2\ (\text{g})+\text{O}_2(\text{g})$
When silver chloride is exposed to light, it decomposes to from silver metal and chlorine gas:$2\text{AgCl}\text{(s)}\ \ \ \ \xrightarrow{\text{Light}}\ \ \ 2\text{Ag}\ (\text{s})+\ \text{Cl}_2(\text{g})$
When electric current is passed through acidified water, it decomposes to give hydrogen gas and oxygen gas. This reaction can be represented as:$2\text{H}_2\text{O}\ (\text{l})\ \ \ \xrightarrow{\text{Electricity}}\ \ \ 2\text{H}_2\ (\text{g})+\text{O}_2(\text{g})$
When silver chloride is exposed to light, it decomposes to from silver metal and chlorine gas:$2\text{AgCl}\text{(s)}\ \ \ \ \xrightarrow{\text{Light}}\ \ \ 2\text{Ag}\ (\text{s})+\ \text{Cl}_2(\text{g})$
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