drawing an enantiomer by not just drawing the reflected image is usually a lot easier

追加: 2026-05-17

[00:00:00]Advanced higher chemist, this one is for you. I find one of the hardest things in chemistry is visualizing molecules in 3D space and therefore trying to identify enantiomers or optical isomers. But I realized there's like a little trick you can do to make your life a little bit easier when it comes to identifying and or drawing enantiomers. So here's a question from the 2016 past paper I think it is and it's an enantiomers question where you're asked to identify the enantiomer of this molecule here. Now a lot of people in textbooks when they draw enantiomers will just draw the mirror image. So they'll just reflect what they can see and that does work. However, it's really very rarely the possible answer. So as you can see we scan down here this thing doesn't actually exist. My tip and trick is actually just to swap the groups that are on the wedge and hash bonds around.

[00:00:50]So if we do that, that gives us this molecule here. See I've just swapped the Z and the Y around and then we can see that actually then the answer is A. But you can do the same thing in paper two if you're asked to draw an enantiomer.

[00:01:01]Just take the molecule that they've given you and then just swap the two groups that they've put on the wedge and hash bonds around.