The structures of two isomers of heptane are shown. Which of these two compounds would you expect to have the greater viscosity?

Video transcript

Hey everyone today, we're being given to molecules hexane and 23 die metal butane. And we're being asked to identify which one is going to be more fiscus, which one will have a higher viscosity now compounds with strong inter molecular forces have higher viscosity. And there are two rules regarding Vander Waals forces that affect viscosity. To rules. The first is the size, so the composition first being size, with heavier molecules being more viscous and the second being the shape. So the rule for the shape of molecules is that rings are more viscous, rings are more viscous than chains, or sorry, straight chains, Straight change cannot spill today. Straight change which are more viscous, then branched branched, change brands chains. So with that in mind let's go ahead and take a look back at hexane and die metal butane. Now both of these have the same chemical composition. They both have a formula of C six H 14. So we can rule out size as the factor that we need to look at. However, 23 dimethyl butane is branched, This is branched while hexane is straight straight. So since hexane is straight, is straight, that means that it has higher dispersion forces. Higher dispersion forces, which means that hexane is more viscous, it has a higher viscosity. I hope this helps and I look forward to seeing you all in the next one