The heat of combustion (AH) for an unknown hydrocarbon is -8.21 kJ/mol. If 0.344 mol of the hydrocarbon is burned in a bomb calorimeter, what is the change in temperature (°C) of the calorimeter? The heat capacity of the bomb calorimeter is 1.12 kJ/°C.
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.
![### Calorimetry Problem: Heat of Combustion
**Problem Statement:**
The heat of combustion (ΔH) for an unknown hydrocarbon is -8.21 kJ/mol. If 0.344 mol of the hydrocarbon is burned in a bomb calorimeter, what is the change in temperature (°C) of the calorimeter? The heat capacity of the bomb calorimeter is 1.12 kJ/°C.
**Analysis:**
To calculate the change in temperature, use the formula:
\[ q = m \times \Delta H \]
Where:
- \( q \) is the heat exchanged (in kJ),
- \( m \) is the number of moles of the substance,
- \( \Delta H \) is the heat of combustion per mole.
1. Calculate the total heat released:
\[ q = 0.344 \, \text{mol} \times (-8.21 \, \text{kJ/mol}) \]
2. Use the formula for heat capacity to find the change in temperature:
\[ \Delta T = \frac{q}{C} \]
Where:
- \( \Delta T \) is the change in temperature (°C),
- \( C \) is the heat capacity of the calorimeter (kJ/°C).
Calculate \( \Delta T \) by substituting the values for \( q \) and \( C \).
This setup will allow students to practice their understanding of thermodynamics and calorimetry concepts.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F622b7d3a-c4ea-4270-a9b2-769c5745ad31%2Fb822f777-69c7-4a97-a5c3-c4fc35192dcd%2Fezw694x_processed.png&w=3840&q=75)
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