The following substances undergo complete combustion in a bomb calorimeter. The calorimeter assembly has a heat capacity of 5.136 ^ C. In each case, what is the final temperature if the initial water temperature is 22.37^ C? 0.3268g caffeine, C8H10N4 (heat of combustion = -1014.2 kcal/mol caffeine)
1014.2 kcal/mol x (0.3268 g/molar mass caffeine) = kcal. Change to cal = ?q
?q = Ccal x (Tfinal-Tinitial).
Solve for Tfinal.
By the way, you omitted the unit for Ccal. That's 5.31 WHAT/degree C. If that is kcal change to cal.
To determine the final temperature after complete combustion in a bomb calorimeter, we can use the equation:
q = m * C * ΔT
Where:
- q is the heat released during the combustion (in this case, the heat of combustion),
- m is the mass of the substance being combusted,
- C is the heat capacity of the calorimeter assembly, and
- ΔT is the change in temperature (final temperature - initial temperature).
First, we need to calculate the heat released (q) during combustion:
q = -1014.2 kcal/mol * (0.3268 g / (194.19 g/mol))
The molar mass of caffeine (C8H10N4) is 194.19 g/mol.
So, q = -1014.2 kcal/mol * 0.0016835 mol = -1.706 kcal
Next, we can rearrange the equation to solve for ΔT:
ΔT = q / (m * C)
ΔT = (-1.706 kcal) / (5.136 ^ C * (0.3268 g) )
Now, let's calculate ΔT:
ΔT ≈ -0.6639 ^ C
Finally, we can calculate the final temperature:
Final temperature = initial temperature + ΔT
Final temperature ≈ 22.37 ^ C + (-0.6639 ^ C)
Final temperature ≈ 21.7061 ^ C
Therefore, the final temperature after the complete combustion of 0.3268 g of caffeine in a bomb calorimeter with a heat capacity of 5.136 ^ C is approximately 21.7061 ^ C.
To determine the final temperature after complete combustion, we can calculate the amount of heat released during the combustion and use it to find the temperature change in the calorimeter.
First, we need to calculate the heat released during the combustion of 0.3268g caffeine using the given heat of combustion (-1014.2 kcal/mol caffeine).
Since the molar mass of caffeine (C8H10N4) is 194.19 g/mol, we can find the number of moles of caffeine:
0.3268g / 194.19 g/mol = 0.001683 mol caffeine.
Now, we can calculate the heat released:
Heat released = moles of caffeine * heat of combustion
Heat released = 0.001683 mol * (-1014.2 kcal/mol caffeine)
Heat released = -1.705 kcal
Next, we can calculate the temperature change using the equation:
Heat released = heat capacity * temperature change
Temperature change = Heat released / heat capacity
Temperature change = -1.705 kcal / 5.136 kcal/^C
Now, let's calculate the final temperature:
Final temperature = Initial temperature + Temperature change
Final temperature = 22.37^C + (-1.705 kcal / 5.136 kcal/^C)
After performing the calculations, you will find the final temperature.