Isooctane, the substance in gasoline from which the term octane rating derives, has the formula C₈H₁₈. Each carbon has four covalent bonds, and the atoms are connected in the sequence shown. Draw the complete structural formula of isooctane.

Video transcript

Hello. Everyone in this video we're being told that is a beauty. So as a molecular formula of this right here is used in refineries to create gasoline grade compounds. Each carbon atom follows the octet rule while each hydrogen only forms one bond due to the duet rule, the sequence of carbon atoms is shown below. So right over here we have are being asked to provide the complete structural formula for isil butane. So the structure is missing hydrant atoms, Each carbon is at is bonded to one carbon. So to complete the structure, we simply add the missing hydrogen atoms. So carbon has a trend where it likes to have four bonds. It can be a triple bond, a single bond or a double bond as long as it has those four bonds. And hydrogen, like we said already likes to form one bonds because of the duet role that's two electrons. So it usually is a terminal atom starting off of this top carbon here, we are only connected to one other carbon. So we need three other bonds. We can simply add in three more hydrants to it. And now we can see that we have four bonds and the carbon is happy Same thing for the hydrant. We have one bond. So the hydrants are happy there as well. So these three carbons are actually identical. So we know we're gonna do the same exact thing. So we can go ahead and just add three high regions here and three Hodgins here Now for our central carbon right in the middle here we have 123 bonds. So we can go ahead and add one more hydrogen there. So my final answer is going to be this molecule here, with the terminal hydrants being included in the structure.