Question
Examples of endothermic reaction
Answers
GPT-4o mini
Endothermic reactions are chemical reactions that absorb heat from their surroundings, resulting in a decrease in temperature of the surrounding environment. Here are some examples of endothermic reactions:
1. **Photosynthesis**: This process in plants converts carbon dioxide and water into glucose and oxygen using sunlight as energy. The overall reaction is:
\[
6 \text{CO}_2 + 6 \text{H}_2\text{O} + \text{light energy} \rightarrow \text{C}_6\text{H}_{12}\text{O}_6 + 6 \text{O}_2
\]
2. **Dissolving ammonium nitrate in water**: When ammonium nitrate (\( \text{NH}_4\text{NO}_3 \)) is dissolved in water, it absorbs heat, resulting in a temperature drop.
\[
\text{NH}_4\text{NO}_3(s) + \text{H}_2\text{O}(l) \rightarrow \text{NH}_4^+(aq) + \text{NO}_3^-(aq) + \text{heat absorbed}
\]
3. **Baking soda and vinegar reaction**: The reaction between sodium bicarbonate (baking soda) and acetic acid (vinegar) is endothermic, as it absorbs heat, although it is often viewed as a weakly exothermic process:
\[
\text{NaHCO}_3(s) + \text{CH}_3\text{COOH}(l) \rightarrow \text{CO}_2(g) + \text{H}_2\text{O}(l) + \text{NaCH}_3\text{COO}(aq)
\]
4. **Thermal decomposition of calcium carbonate**: When calcium carbonate (\( \text{CaCO}_3 \)) is heated, it breaks down into calcium oxide (\( \text{CaO} \)) and carbon dioxide (\( \text{CO}_2 \)), absorbing heat in the process.
\[
\text{CaCO}_3(s) + \text{heat} \rightarrow \text{CaO}(s) + \text{CO}_2(g)
\]
5. **Dissolving of some salts**: Certain salts, like potassium nitrate (\( \text{KNO}_3 \)), when dissolved in water, also absorb heat.
\[
\text{KNO}_3(s) + \text{H}_2\text{O}(l) \rightarrow \text{K}^+(aq) + \text{NO}_3^-(aq) + \text{heat absorbed}
\]
6. **Formation of nitrogen gas from nitrogen monoxide and oxygen**:
\[
2 \, \text{NO}(g) + \text{O}_2(g) + \text{heat} \rightarrow 2 \, \text{NO}_2(g)
\]
These examples illustrate how endothermic reactions play a key role in various chemical processes, often involving the absorption of heat or energy from the environment.
1. **Photosynthesis**: This process in plants converts carbon dioxide and water into glucose and oxygen using sunlight as energy. The overall reaction is:
\[
6 \text{CO}_2 + 6 \text{H}_2\text{O} + \text{light energy} \rightarrow \text{C}_6\text{H}_{12}\text{O}_6 + 6 \text{O}_2
\]
2. **Dissolving ammonium nitrate in water**: When ammonium nitrate (\( \text{NH}_4\text{NO}_3 \)) is dissolved in water, it absorbs heat, resulting in a temperature drop.
\[
\text{NH}_4\text{NO}_3(s) + \text{H}_2\text{O}(l) \rightarrow \text{NH}_4^+(aq) + \text{NO}_3^-(aq) + \text{heat absorbed}
\]
3. **Baking soda and vinegar reaction**: The reaction between sodium bicarbonate (baking soda) and acetic acid (vinegar) is endothermic, as it absorbs heat, although it is often viewed as a weakly exothermic process:
\[
\text{NaHCO}_3(s) + \text{CH}_3\text{COOH}(l) \rightarrow \text{CO}_2(g) + \text{H}_2\text{O}(l) + \text{NaCH}_3\text{COO}(aq)
\]
4. **Thermal decomposition of calcium carbonate**: When calcium carbonate (\( \text{CaCO}_3 \)) is heated, it breaks down into calcium oxide (\( \text{CaO} \)) and carbon dioxide (\( \text{CO}_2 \)), absorbing heat in the process.
\[
\text{CaCO}_3(s) + \text{heat} \rightarrow \text{CaO}(s) + \text{CO}_2(g)
\]
5. **Dissolving of some salts**: Certain salts, like potassium nitrate (\( \text{KNO}_3 \)), when dissolved in water, also absorb heat.
\[
\text{KNO}_3(s) + \text{H}_2\text{O}(l) \rightarrow \text{K}^+(aq) + \text{NO}_3^-(aq) + \text{heat absorbed}
\]
6. **Formation of nitrogen gas from nitrogen monoxide and oxygen**:
\[
2 \, \text{NO}(g) + \text{O}_2(g) + \text{heat} \rightarrow 2 \, \text{NO}_2(g)
\]
These examples illustrate how endothermic reactions play a key role in various chemical processes, often involving the absorption of heat or energy from the environment.