madey21
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[tex]$5.00 \, \text{g}$[/tex] 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].

[tex]$T _{ i } = 20.2^{\circ} \text{C}$[/tex]
[tex]$T _{ f } = 22.0^{\circ} \text{C}$[/tex]

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

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

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



Answer :

To find the enthalpy of the reaction in [tex]\( \text{kJ/g} \)[/tex], we need to follow a few steps. The main points to focus on are the heat capacity of the calorimeter, the initial and final temperatures, and the mass of the banana. Here’s a detailed step-by-step solution:

1. Determine the change in temperature (ΔT):

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

The change in temperature, ΔT, is calculated as:
[tex]\[ \Delta T = T_f - T_i \][/tex]
[tex]\[ \Delta T = 22.0^\circ \text{C} - 20.2^\circ \text{C} = 1.8^\circ \text{C} \][/tex]

2. Calculate the heat absorbed by the calorimeter (q):

Given:
- Heat capacity of the calorimeter, [tex]\( C = 10.3 \text{ kJ/}^\circ \text{C} \)[/tex]

The heat absorbed, [tex]\( q \)[/tex], is given by:
[tex]\[ q = C \times \Delta T \][/tex]
[tex]\[ q = 10.3 \text{ kJ/}^\circ \text{C} \times 1.8^\circ \text{C} = 18.54 \text{ kJ} \][/tex]

3. Calculate the enthalpy of the reaction (ΔH) per gram of banana:

Given:
- Mass of the banana, [tex]\( m = 5.00 \text{ g} \)[/tex]

The enthalpy change, [tex]\( \Delta H \)[/tex], per gram of banana is calculated by:
[tex]\[ \Delta H = \frac{q}{\text{mass of the banana}} \][/tex]
[tex]\[ \Delta H = \frac{18.54 \text{ kJ}}{5.00 \text{ g}} = 3.708 \text{ kJ/g} \][/tex]

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

Note the significant figures are preserved throughout the calculation, reflecting the precision of the given data.