the enthalpy of combustion of benzoic acid C6H5COOH, which is used to calibrate calorimeters usualmete is -3227 kJ mol-1. burning 1.453g of benzoic acid into a calorimeter, the 2,265 ° C temperature increase what is the heat capacity of the calorimeter?
Convert 1.453 g benzoic acid to mols. mols = grams/molar mass = ?
q = Ccal x (Tfinal-Tinitial)
+3227000 x mol = Ccal x (delta T)
You know everything but Ccal. I wonder if that is 2.265 T increase.
To find the heat capacity of the calorimeter, you can use the equation:
Q = m * C * ΔT
Where:
Q = Heat transferred (in joules)
m = Mass of the benzoic acid (in grams)
C = Heat capacity of the calorimeter (in joules per degree Celsius)
ΔT = Temperature increase (in degrees Celsius)
First, let's convert the mass of benzoic acid from grams to moles:
1.453 g * (1 mol / molar mass of benzoic acid) = X mol
The molar mass of benzoic acid (C6H5COOH) is calculated as follows:
C = 6 * atomic mass of carbon = 6 * 12.01 g/mol = 72.06 g/mol
H = 5 * atomic mass of hydrogen = 5 * 1.01 g/mol = 5.05 g/mol
O = 2 * atomic mass of oxygen = 2 * 16.00 g/mol = 32.00 g/mol
Total molar mass = 72.06 + 5.05 + 32.00 = 109.11 g/mol
Now, calculate the number of moles:
1.453 g * (1 mol / 109.11 g) = 0.0133 mol
Next, rearrange the equation to solve for the heat capacity, C:
C = Q / (m * ΔT)
The heat transferred can be calculated using the enthalpy of combustion of benzoic acid:
Q = -3227 kJ/mol * 0.0133 mol = -42.88 kJ
Since the temperature increase is given as 2,265°C, we need to convert it to degrees Celsius:
ΔT = 2265°C - 25°C = 2240°C
Now, convert to Kelvin:
ΔT = 2240°C + 273.15 K = 2513.15 K
Finally, substitute the values into the equation to find the heat capacity of the calorimeter:
C = (-42.88 kJ) / (1.453 g * 2513.15 K)
Calculating the result gives you the heat capacity of the calorimeter in J/°C.
To calculate the heat capacity of the calorimeter, we can use the formula:
q = mcΔT
Where:
q = heat energy
m = mass of the substance (benzoic acid)
c = specific heat capacity of the substance (calorimeter)
ΔT = change in temperature
First, we need to convert the mass of benzoic acid from grams to moles. The molar mass of benzoic acid (C6H5COOH) can be calculated as:
Molar mass of C6H5COOH = (6 * atomic mass of C) + (5 * atomic mass of H) + atomic mass of C + 2 * atomic mass of O + atomic mass of H
Next, we can calculate the number of moles of benzoic acid using the given mass and molar mass.
Number of moles = mass of benzoic acid / molar mass of benzoic acid
Once we know the number of moles, we can calculate the heat energy released during the combustion of benzoic acid using the enthalpy of combustion value (-3227 kJ/mol).
Heat energy = enthalpy of combustion * number of moles
Now, we have the heat energy and the temperature increase (ΔT). We can substitute these values into the formula q = mcΔT to solve for the specific heat capacity of the calorimeter (c).
c = q / (mΔT)
Substitute the known values into the equation and solve for c, which will give us the heat capacity of the calorimeter.