ALEKS: Finding a molecular formula from molar mass and elemental analysis

[@vinc8ntl8r]

thank you for saving my sanity you're the best

[@RoxiHulet]

Happy to help!!

[@JustinSmith-jy8gb]

you're amazing thank you

[@nickolodan612]

Thanks so much! Your vids are super helpful I'd be so lost without them

[@RoxiHulet]

Glad you like them!

[@amyzhang783]

Thank you so much! I should've read closer because I kept giving them the emprical formula lol

[@RoxiHulet]

It happens! The problems are so similar, it's easy to get them mixed up. :)

[@Hmontecillo]

Hi Roxi! I was watching your video and I do not know If this is a typo but, the atomic mass for Carbon is 12.011 and you might've listed it as 12.001 about 6:10-6:11 minutes into the video.

[@RoxiHulet]

You are 100% correct! Thanks for letting me know! Thankfully I did get it right earlier in the problem! Sorry for the confusion it might have cause! :)

[@sarahamro7439]

I have a question. Is there a specific order that the molecular formula needs to be written? I looked it up and it says C comes first then H, and then everything else in alphabetical order. I did a problem with Nitrogen and Fluorine, and I put fluorine first since F comes before N but it says its wrong. Why would N come before F?

[@RoxiHulet]

This is an excellent question and such a frustrating part of this type of problem! Molecules that are hydrocarbons (containing C, H, and other elements) will follow the rule of C first, H second, everything else alphabetical. Ionic compounds list the cation first and the anion second. Other compounds list the most electronegative element last (if you have not learned about electronegativity, that's not helpful). A pretty reliable rule of thumb is to put them in the same order as they appear on the periodic table (reading from left to right, so N comes before F, P comes before Cl, Si comes before S, Na comes before O) but that's not going to always work. Like I said, frustrating!! Hang in there!

[@Wildernessmanchungus]

if only someone made my pre-calc make this much sense

[@RoxiHulet]

Nobody can make pre-calc make sense haha

[@jennifergaspar7]

UR THE BEST! LOVE U QUEEN!! THXXX🙏

[@RoxiHulet]

XO Thank you!

[@lorionah]

i should be paying you tuition

[@RoxiHulet]

I love you for this ❤️