The heat of atomization is the heat required to convert a molecule in the gas phase into its constituent atoms in the gas phase. The heat of atomization is used to calculate average bond energies. Without using any tabulated bond energies, calculate the average C¬Cl bond energy from the following data: the heat of atomization of CH4 is 1660 kJ>mol, and the heat of atomization of CH2Cl2 is 1495 kJ>mol.

Video transcript

everyone in this example, we're told that the heat of optimization is defined as the entropy change. That accompanies the total breakdown of a molecule into its constituent atoms during the gas phase. We're told that the heat of atomization of silence is 1194 kg per mole While it is 1351 kg formal for chloral silent. So using our given data, we need to calculate them on energy for our silicon chlorine single bond. So we want to go ahead and analyze how many silicon hydrogen single bonds we have in our silent molecule. And so we would say that there are a total of four silicon hydrogen bonds, single bonded bonds in silence. And so when we look up our bond energy for this type of bond here, we would see that it corresponds to a bond energy of 194. Which we will then divide by these four bonds present in this molecule. And this 1194 comes from the heat of adam ization for silent given in the question. So we're going to divide this by the total of four silicon hydrogen single bonds in silence. And this gives us the bond energy equal to a value of 98.5 kg joules per mole for our silicon hydrogen bond. Next, we want to analyze how many silicon hydrogen single bonds are in our chloral silent. And so we would recognize that we have a total of three silicon hydrogen bonds. When we look at the molecule of our chloral silent. And so we also want to recognize that within this close island molecule, we also have one silicon chlorine bond. So we want to go ahead and find our bond energy by taking this given heat of atomization for our Claro cylon which is given as 1,351 kg joules per mole. And we're going to set that equal to the three silicon hydrogen single bonds in our close eileen. So this is going to be equal to three of those bonds multiplied by their bond energies which we above stated are equal to 98.5 kg joules per mole. And then this is going to be added to our bond energy of our silicon chlorine single bond, which is what we're trying to solve for. So we can simplify this so that we have 1351 kg joules per mole equal to the product of our bond energy times three equal to 95.5 kg joules per mole. And then added to our bond energy or bond entropy of our silicon chlorine single bond. So in order to isolate for our bond energy of the silicon chlorine single bond, we're going to subtract both 8 95. from both sides of our equation. And so this is going to give us our bond entropy or bond energy for our silicon chlorine single bond equal to a value of 455.5 kg joules per mole. And this is going to complete this example as our final answer for the bond energy of our silicon chlorine single bond in our chlor oh, silent molecule. So I hope that everything we reviewed was clear. If you have any questions, please leave them down below, and I'll see everyone in the next practice video.