Enthalpy is the energy absorbed or released when a chemical change occurs. Assume you have the following thermochemical reaction: 2H2S(9) + 302(g) -> 2SO2(g) + 2H2O(g); AH = -1036 KJ How much energy is absorbed or released when 19.6 g of hydrogen sulfide (H2S) is burned? Is this an exothermic or endothermic reaction? Show all work for full credit.
Thermochemistry
Thermochemistry can be considered as a branch of thermodynamics that deals with the connections between warmth, work, and various types of energy, formed because of different synthetic and actual cycles. Thermochemistry describes the energy changes that occur as a result of reactions or chemical changes in a substance.
Exergonic Reaction
The term exergonic is derived from the Greek word in which ‘ergon’ means work and exergonic means ‘work outside’. Exergonic reactions releases work energy. Exergonic reactions are different from exothermic reactions, the one that releases only heat energy during the course of the reaction. So, exothermic reaction is one type of exergonic reaction. Exergonic reaction releases work energy in different forms like heat, light or sound. For example, a glow stick releases light making that an exergonic reaction and not an exothermic reaction since no heat is released. Even endothermic reactions at very high temperature are exergonic.
![**Thermochemical Reaction and Enthalpy Explanation**
Enthalpy is the energy absorbed or released when a chemical change occurs. Consider the following thermochemical reaction:
\[ 2\text{H}_2\text{S}_{(g)} + 3\text{O}_2_{(g)} \rightarrow 2\text{SO}_2_{(g)} + 2\text{H}_2\text{O}_{(g)}; \quad \Delta H = -1036 \text{ kJ} \]
**Problem Statement:**
How much energy is absorbed or released when 19.6 g of hydrogen sulfide (H₂S) is burned? Is this an exothermic or endothermic reaction?
*Note:* Show all work for full credit.
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**Explanation:**
- The reaction given indicates that 2 moles of H₂S gas react with 3 moles of O₂ gas to produce 2 moles of SO₂ gas and 2 moles of H₂O gas.
- The change in enthalpy (\(\Delta H\)) for the reaction is \(-1036 \text{ kJ}\), indicating that the reaction releases energy.
- Determine if this process is exothermic or endothermic.
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An exothermic reaction releases energy (negative \(\Delta H\)), whereas an endothermic reaction absorbs energy (positive \(\Delta H\)).](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2Ff8df2fb6-e1db-4c52-b56b-e94a0defde0d%2F627fba60-5504-4fc4-9c3a-9641fc3dcd1a%2Fj4kw65_processed.jpeg&w=3840&q=75)
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