A sample of sucrose(table sugar) with a mass of 1.32g is burned in a 1L bomb calori meter. The temperature changed from 25degree celcius to 27.31 degree celcius. Calculate the heat of combustion of sucrose in units of KJ/mol. The formular of sucrose is C12H22O11
Note the correct spelling of celsius.
q = mass H2O x specific heat H2O x (Tfinal-Tinitial)
q = heat combustion
heat combustion/g = q/1.32g\
heat combustion/mol = (q/1.32)*molar mass. This will be in J/mol. Convert to kJ/mol.
To calculate the heat of combustion of sucrose (C12H22O11), we need to use the equation:
ΔH = q / n
Where ΔH is the heat of combustion per mole (in KJ/mol), q is the heat transferred (in KJ), and n is the number of moles.
First, we need to calculate the heat transferred (q) using the equation:
q = m × c × ΔT
Where q is the heat transferred (in KJ), m is the mass of the sample (in grams), c is the specific heat capacity of water (which is approximately 4.18 J/g°C), and ΔT is the change in temperature (in °C).
Given data:
- Mass of sample (m): 1.32 g
- Change in temperature (ΔT): 27.31°C - 25°C = 2.31°C
Converting the mass of the sample to grams:
m = 1.32 g
Converting the temperature change to Kelvin:
ΔT = 2.31 K
Now, we can calculate the heat transferred (q):
q = m × c × ΔT
q = 1.32 g × 4.18 J/g°C × 2.31 K
q ≈ 12.2204 J
Next, we need to calculate the number of moles (n) of sucrose:
To find the number of moles, we need to know the molar mass of sucrose (C12H22O11).
The molar mass of C12H22O11 can be calculated as follows:
12.01 g/mol (for C) × 12 atoms = 144.12 g/mol
1.01 g/mol (for H) × 22 atoms = 22.22 g/mol
16.00 g/mol (for O) × 11 atoms = 176.00 g/mol
Adding them together, we get:
144.12 g/mol + 22.22 g/mol + 176.00 g/mol = 342.34 g/mol
Now, we can calculate the number of moles (n) of sucrose:
n = m / M
n = 1.32 g / 342.34 g/mol
n ≈ 0.00385 mol
Finally, we can calculate the heat of combustion per mole (ΔH) of sucrose:
ΔH = q / n
ΔH = 12.2204 J / 0.00385 mol
To convert J to KJ, we divide the result by 1000:
ΔH ≈ 3.1775 KJ/mol
Therefore, the heat of combustion of sucrose is approximately 3.1775 KJ/mol.
To calculate the heat of combustion of sucrose (C12H22O11), we need to use the equation:
Heat of Combustion = q / moles of sucrose
First, let's calculate the amount of heat transferred (q) using the equation:
q = m * Cs * ΔT
Where:
- m is the mass of the sample of sucrose (1.32g)
- Cs is the specific heat capacity of water (4.18 J/(g·°C))
- ΔT is the change in temperature (27.31°C - 25°C = 2.31°C)
Now, we can calculate the amount of heat transferred:
q = (1.32g) * (4.18 J/(g·°C)) * (2.31°C)
= 12.1128 J
Next, we need to calculate the number of moles of sucrose used in the combustion. To do this, we'll use the molar mass of sucrose.
The molar mass of C12H22O11 is calculated as follows:
(12.01g * 12) + (1.008g * 22) + (16.00g * 11) = 342.3g/mol
We can now calculate the number of moles:
moles of sucrose = (1.32g) / (342.3g/mol)
Finally, we can calculate the heat of combustion using the obtained values:
Heat of Combustion = q / moles of sucrose
= (12.1128 J) / (1.32g / 342.3g/mol)
= 1161.8416 J/mol
To convert the result to kilojoules, divide by 1000:
Heat of Combustion = 1161.8416 J/mol / 1000
= 1.16184 KJ/mol
Therefore, the heat of combustion of sucrose is approximately 1.16184 KJ/mol.