## Molecular formula from shape

(Polar molecules, Non-polar molecules, etc.)

Crystal Odipo 1F
Posts: 42
Joined: Wed Sep 30, 2020 9:53 pm

### Molecular formula from shape

When trying to determine the molecular formula on a structure do the double bonds hold any significance?

Minh Nguyen 3A
Posts: 30
Joined: Wed Sep 30, 2020 9:36 pm

### Re: Molecular formula from shape

I'd like to know about this too! There was a problem on the sapling homework where I ignored the double bonds and it worked out fine, but I'm still wondering whether or not the double bonds would matter outside of the homework.

Teti Omilana 2E
Posts: 40
Joined: Wed Sep 30, 2020 10:05 pm

### Re: Molecular formula from shape

I'm pretty sure if you're just trying to figure out the molecular formula, no they do not hold any significance. Like for example on Question #8 on Sapling, you only have to count how many times each element appears in the molecule to find the molecular formula, which the double bonds have no effect on.

Hannah Alltucker 2H
Posts: 54
Joined: Wed Sep 30, 2020 9:44 pm

### Re: Molecular formula from shape

I would say that you only really need to worry about double bonds when finding the molecular formula when dealing with the condensed organic lewis structure formulas, which is what we saw on one of the sapling homework problems. By using it, you can determine how many carbons, hydrogens, etc. are in the structure, and a double bond simply means that that atom would not be connected to an extra H like it would if it were only a single bond since the carbon would already be bonded to four other atoms (using the first chemical in the homework problem as an example)

ShinwooKim_3E
Posts: 40
Joined: Wed Sep 30, 2020 10:00 pm

### Re: Molecular formula from shape

You can't figure out how many double bonds a structure has just by looking at its chemical formula (that's why we draw models)!

Michelle Nguyen 2C
Posts: 42
Joined: Wed Sep 30, 2020 10:03 pm

### Re: Molecular formula from shape

For finding the molecular formula, no the structure and double bonds do not hold significance. It's basically counting up how many elements and how many of each element there are. However, if you are trying to find the Lewis structure from the molecular formula, you would have to draw it out, and that's when double bonds hold significance.