Given the following information:
N₂ bond energy = 941 kJ/mol
F₂ bond energy = 154 kJ/mol
Calculate the N-F bond energy.

Question

Given the following information: N₂ bond energy = 941 kJ/mol F₂ bond energy = 154 kJ/mol Calculate the N-F bond energy.

Quizplus · Accepted Answer

To calculate the N-F bond energy, we need to use the following equation:
N2(g) + 3F2(g) → 2NF3(g)

From the given bond energies, we can calculate the energy required to break the bonds in the reactants:
N2(g) + 6S1U1B0(g) → 2NS1U1B12S1U1B0(g)      ΔH = 2(941 kJ/mol) = 1882 kJ/mol
3F2(g) → 6S1U1B0(g) + FS1U1B12S1U1B0(g)    ΔH = 3(154 kJ/mol) = 462 kJ/mol

We can see that in the products, we have two NS1U1B12S1U1B0 bonds and one FS1U1B12S1U1B0 bond. Therefore, the total bond energy in the products is:
(2 x 941 kJ/mol) + (1 x x kJ/mol) = 1882 + x kJ/mol
where x is the N-F bond energy that we want to calculate.

Now we can use the law of conservation of energy to calculate x:
Energy required to break bonds in reactants = Energy released by forming bonds in products
1882 + 462 kJ/mol = (2 x 941 kJ/mol) + x kJ/mol
2344 kJ/mol = 1882 kJ/mol + x kJ/mol
x = 2344 kJ/mol - 1882 kJ/mol
x = 462 kJ/mol

Therefore the N-F bond energy is 462 kJ/mol, which corresponds to choice B.

Given the Following Information