College

We appreciate your visit to A 6 55 g sample of aniline tex C 6H 5NH 2 tex with a molar mass of tex 93 13 text g mol tex. This page offers clear insights and highlights the essential aspects of the topic. Our goal is to provide a helpful and engaging learning experience. Explore the content and find the answers you need!

A 6.55 g sample of aniline [tex] (C_6H_5NH_2) [/tex], with a molar mass of [tex] 93.13 \, \text{g/mol} [/tex], was combusted in a bomb calorimeter. If the temperature rose by [tex] 32.9^{\circ} C [/tex], use the information below to determine the heat capacity of the calorimeter.

**Reaction:**

[tex] 4 \, C_6H_5NH_2(l) + 35 \, O_2(g) \rightarrow 24 \, CO_2(g) + 14 \, H_2O(g) + 4 \, NO_2(g) [/tex]

**Given:**

[tex] \Delta H^{\circ}_{\text{rxn}} = -1.28 \times 10^4 \, \text{kJ} [/tex]

**Choices:**

A) [tex] 97.3 \, \text{kJ/}^{\circ} C [/tex]
B) [tex] 38.9 \, \text{kJ/}^{\circ} C [/tex]
C) [tex] 5.94 \, \text{kJ/}^{\circ} C [/tex]
D) [tex] 6.84 \, \text{kJ/}^{\circ} C [/tex]
E) [tex] 12.8 \, \text{kJ/}^{\circ} C [/tex]

Answer :

To determine the heat capacity of the calorimeter, we can follow these steps:

1. Calculate the Moles of Aniline:
We are given the mass of aniline as 6.55 g and its molar mass as 93.13 g/mol. To find the moles of aniline, use the formula:
[tex]\[
\text{moles of aniline} = \frac{\text{mass}}{\text{molar mass}} = \frac{6.55 \, \text{g}}{93.13 \, \text{g/mol}}
\][/tex]
This calculation gives approximately 0.0703 moles of aniline.

2. Calculate the Heat Released:
The standard enthalpy change of the reaction [tex]\((\Delta H^{\circ}_{rxn})\)[/tex] is given as [tex]\(-1.28 \times 10^4 \, \text{kJ}\)[/tex] for the combustion of aniline according to the balanced equation. To find the heat released ([tex]\(q\)[/tex]) during the combustion of the given moles of aniline:
[tex]\[
q = \text{moles of aniline} \times \Delta H^{\circ}_{rxn} = 0.0703 \times (-1.28 \times 10^4 \, \text{kJ/mol})
\][/tex]
This results in approximately [tex]\(-900.25 \, \text{kJ}\)[/tex] of heat released.

3. Calculate the Heat Capacity of the Calorimeter:
The heat capacity of the calorimeter ([tex]\(C\)[/tex]) can be calculated using the formula:
[tex]\[
C = \frac{q}{\Delta T}
\][/tex]
where [tex]\(\Delta T\)[/tex] is the change in temperature, which is 32.9°C. Substituting the values:
[tex]\[
C = \frac{-900.25 \, \text{kJ}}{32.9 \, \text{°C}}
\][/tex]
This calculation gives approximately [tex]\(-27.36 \, \text{kJ/°C}\)[/tex].

This result indicates that the heat capacity of the calorimeter is about [tex]\(-27.36 \, \text{kJ/°C}\)[/tex]. However, since heat capacity is typically considered a positive value, we can consider the magnitude, which is closest to none of the given options. There might be an issue with the options that were provided.

Thanks for taking the time to read A 6 55 g sample of aniline tex C 6H 5NH 2 tex with a molar mass of tex 93 13 text g mol tex. We hope the insights shared have been valuable and enhanced your understanding of the topic. Don�t hesitate to browse our website for more informative and engaging content!

Rewritten by : Barada