When 0.500 mol of N2O4 is placed in a 4.00-L reaction vessel and heated at 400 K, 79.3% of the N2O4 decom- poses to NO2. (b) Draw an electron-dot structure for NO2, and rational- ize the structure of N2O4.

Video transcript

We have the following problem, 78 of phosphorous chloride decomposes to phosphorus chloride And regular chloride gas upon heating a one liter reaction vessel containing 2. molars moles of phosphorus chloride to 350 Kelvin provide the lewis structure for chloride and propose a structure for phosphorus chloride. So first we want to work on our chloride or CO2. You want to note that our chloride or chlorine is a group seven a element. And if it is a group seven a element, it has seven valence electrons. So for one chlorine, Who said it in group 78 for one chlorine, there are seven valence electrons. And since there are two present in chlorine gas, we have 14 total electrons to work with. Also it's important to note that because Corn is a group seven a element. It likes to form one bond, So it forms one bond. And so in constructing our formula for it, we can have one chlorine, wanted to the second glory and there's that one bond here and one bond equals two electrons. So we now just have to draw the remaining electrons around each chlorine. So each chlorine is going to receive a six electrons around it giving us our lewis dot structure for chlorine gas. Next we want to worry about our phosphorus chloride. This involves three separate elements. We have phosphorus, we have oxygen and we have chlorine. Now phosphorus is a group three A element. And so therefore it has three valence electrons and there's only one of them oxygen Is a group six a element. So it has six valence electrons. And it's only one of them. And then chlorine here is a group seven a element as we established earlier. And so it has seven valence electrons. However there are three of them. So we have a total of 21 electrons with our chlorine. So adding these values up, We get a total of 30 valence electrons to work with. It's important to note That since oxygen is a group six a element, it forms two bonds. It was already established that chlorine forms one bond and phosphorus is a little different. So usually it can form three bombs but it can expand its context but it can expand its octet to accommodate more bonds. In fact any element that is a group That is a period three element where the ferry row and below can expand it to 10. So using these principles, what we can do is we can go ahead and put this phosphorus in the center and we can surround it by our one chlorine to chlorine and three chlorine. We then can add our oxygen Being formed by a double bond since it forms two bonds. And so since each of these bonds represents two electrons, we have 12345. We have 20 more electrons to fill out. And so we're gonna go ahead and place them around each of our elements here as shown. And in doing that we have a structure for our phosphorus chloride and for our chlorine gas. And so with that we've answered the question overall, I hope that this helped, and until next time.