Question
Calculate the enthalpy change , in kJ, for this dissociation of mole of propan-1-ol. C_(3)H_(7)OH(g)arrow 3C(g)+8H(g)+O(g) C-H C-C C-O O -H Mean bond dissociation enthalpy / 412348_360463 kJmol^-1 Select one: -4751 -4403 +4403 +4751
Answer
4
(314 Votes)
Carter
Veteran · Tutor for 9 years
Answer
Substituting the given bond energies into the formula, we get:### \( \text{Total energy} = (7 \times 412) + (2 \times 348) + (1 \times 360) + (1 \times 463) = 4751 \, \text{kJ/mol} \)The enthalpy change for the dissociation of one mole of propan-1-ol is therefore
. The positive sign indicates that energy is absorbed in the process, which is characteristic of bond-breaking processes.
Explanation
## Step 1: Identify the bonds in the moleculeThe molecule C3H7OH has the following bonds: 7 C-H bonds, 2 C-C bonds, 1 C-O bond, and 1 O-H bond.## Step 2: Calculate the total energy required to break the bondsThe total energy required to break the bonds in one mole of propan-1-ol is the sum of the energy required to break each type of bond, multiplied by the number of each type of bond in the molecule.### \( \text{Total energy} = (7 \times \text{C-H bond energy}) + (2 \times \text{C-C bond energy}) + (1 \times \text{C-O bond energy}) + (1 \times \text{O-H bond energy}) \)## Step 3: Substitute the given bond energies into the formulaSubstitute the given bond energies into the formula and calculate the total energy.