heat released = q = Ccal x (delta T) and I would work in J again everywhere.
Then q/gram = q/1.283 = x
Convert to J/mol by x*molar mass and that needs to be conert to kJ/mol because of the directions in the problem.
Then q/gram = q/1.283 = x
Convert to J/mol by x*molar mass and that needs to be conert to kJ/mol because of the directions in the problem.
q/1.283 = 3841(130.32)
I know you have to divide by the molar mass which I found to be 132.169 but Im not sure which number I divide it by.
To calculate the molar enthalpy of combustion (ΔHcomb), we need to use the equation:
ΔHcomb = q / n
Where q is the heat released by the combustion and n is the number of moles of cinnamaldehyde.
Now, let's calculate q, shall we?
q = Ccalorimeter * ΔT
Where Ccalorimeter is the heat capacity of the calorimeter and ΔT is the change in temperature.
Substituting the given values, we get:
q = 3.841 kJ/C * 130.32 C
Now, let's convert the mass of cinnamaldehyde to moles, using its molar mass.
Molar mass of C9H8O = 9 * atomic mass of C + 8 * atomic mass of H + atomic mass of O
Mass of C9H8O = 1.283 g
n = Mass / Molar mass
Finally, we put it all together to find ΔHcomb!
ΔHcomb = q / n
Now, don't get burned by this equation! Give it a try and let me know if you need more help!
ΔHcomb = q / n
where:
ΔHcomb = molar enthalpy of combustion (kJ/mol)
q = heat absorbed by the calorimeter (kJ)
n = number of moles of cinnamaldehyde burned
First, we need to find the heat absorbed by the calorimeter (q). We can use the equation:
q = Ccalorimeter * ΔT
where:
q = heat absorbed by the calorimeter (kJ)
Ccalorimeter = heat capacity of the calorimeter (kJ/°C)
ΔT = change in temperature (°C)
Now, let's calculate q:
q = 3.841 kJ/°C * 130.32 °C
q = 499.65 kJ
Next, we need to determine the number of moles of cinnamaldehyde burned. We can use the molar mass of cinnamaldehyde to find the number of moles:
molar mass of C9H8O = (12.01 g/mol * 9) + (1.01 g/mol * 8) + (16.00 g/mol * 1)
molar mass of C9H8O = 104.07 g/mol
Now, let's calculate the number of moles:
n = mass / molar mass
n = 1.283 g / 104.07 g/mol
n = 0.01234 mol
Finally, we can calculate the molar enthalpy of combustion ΔHcomb:
ΔHcomb = q / n
ΔHcomb = 499.65 kJ / 0.01234 mol
ΔHcomb ≈ 40,509 kJ/mol
Therefore, the molar enthalpy of combustion (ΔHcomb) of cinnamaldehyde is approximately 40,509 kJ/mol.