madey21
Answered

A 5.00 g sample of banana reacts with excess oxygen in a bomb calorimeter that has a heat capacity of [tex]$10.3 \, \text{kJ}/^{\circ}\text{C}$[/tex].

Initial temperature, [tex]T_i = 20.2^{\circ}\text{C}[/tex]
Final temperature, [tex]T_f = 22.0^{\circ}\text{C}[/tex]

What is the enthalpy of the reaction, in [tex]\text{kJ/g}[/tex]?

[tex]\Delta H = \, [?] \, \text{kJ/g}[/tex]

Hint: Find the [tex]q \, (\text{kJ})[/tex], then the [tex]\Delta H \, (\text{kJ/g})[/tex].
Enter either a + or - sign AND the magnitude. Do not round until the end. Use significant figures.



Answer :

To determine the enthalpy of the reaction per gram ([tex]\(\Delta H\)[/tex]) for the given problem, we will follow these steps:

1. Calculate the temperature change ([tex]\(\Delta T\)[/tex]):
[tex]\[ \Delta T = T_\text{final} - T_\text{initial} \][/tex]
Given:
[tex]\[ T_\text{initial} = 20.2^\circ C \][/tex]
[tex]\[ T_\text{final} = 22.0^\circ C \][/tex]
[tex]\[ \Delta T = 22.0^\circ C - 20.2^\circ C = 1.8^\circ C \][/tex]

2. Calculate the heat absorbed by the calorimeter ([tex]\(q\)[/tex]):
[tex]\[ q = \text{Heat Capacity} \times \Delta T \][/tex]
Given:
[tex]\[ \text{Heat Capacity} = 10.3 \, \text{kJ/}^\circ \text{C} \][/tex]
[tex]\[ q = 10.3 \, \text{kJ/}^\circ \text{C} \times 1.8^\circ C = 18.54 \, \text{kJ} \][/tex]

3. Calculate the enthalpy change ([tex]\(\Delta H\)[/tex]) per gram of banana:
[tex]\[ \Delta H = \frac{q}{\text{mass of banana}} \][/tex]
Given:
[tex]\[ \text{mass of banana} = 5.00 \, \text{g} \][/tex]
[tex]\[ \Delta H = \frac{18.54 \, \text{kJ}}{5.00 \, \text{g}} = 3.708 \, \text{kJ/g} \][/tex]

Therefore, the enthalpy of the reaction, [tex]\(\Delta H\)[/tex], is:
[tex]\[ \Delta H = +3.708 \, \text{kJ/g} \][/tex]

This result indicates that [tex]\(3.708 \, \text{kJ}\)[/tex] of energy is absorbed per gram of banana during the reaction. Notice the positive sign indicates an endothermic reaction, meaning the system absorbs heat.