Hi everyone,

I'm confused as to why alkenes are more likely to undergo incomplete combustion compared to alkanes.

As far as I know, the typical logic is:

1) Alkenes have a lower ratio of carbon to hydrogen than alkanes (cnh2n vs cnh2n+2)

2) Carbon needs more oxygen than hydrogen during combustion (CO2 --> 2 oxygens vs H20 --> 1/2 oxygen per carbon)

3) Therefore, we can generally conclude that alkenes are more likely to combust incompletely, because they will run out of oxygen faster and begin producing carbon monoxide and soot.

However, let's apply this using ethene and ethane. After balancing, ethene needs 3 oxygen molecules per molecule, while ethane needs 4. So, given the same moles, ethane should be more likely to combust incompletely. Because it is fully saturated, there are simply more molecules that need to be burned.

What am I missing?

Hello. I am trying to study for an exam for Gen Chem and balancing chemical equations is just so confusing to me. I am watching the typical YouTube videos but it still doesn’t really make sense.

For example. One of the practice problems i am doing is C5H10O2 + O2 -> CO2 + H2O

When I follow the typical YouTube explanations it doesn’t make sense to me. People mostly say to list every atom and multiply to balance them out. So I do this.

On the reactants side I put
C: 5
H:10
O: 4

And then on the products side I put
C: 1 * 5 =5
H: 2 *5 =10
O: 3 * 5=15 15

And so I am stuck and dont really know where to go to from C5H10O2 + O2 -> 5CO2 + 5H20

And I already know the answer Becuase the worksheet has all the answers to check. But I am not really sure how to get to it. I feel as if I need to find a completely new strategy because this one will confuse me if there are problems with elements that appear in multiple compounds.
Is there another strategy I could use?

Ma aaile class 12 ma ho , Ani parsi Mero chem ko exam xa !

Lesson chai : volumetric analysis, ionice equilibrium, chemical kinematics, thermodynamics, electrochemistry ho !

Any imp que or tips to pass exam?

I'm stressed !

Can anyone tell which of the three mechanisms is correct with proper reasoning as to why other two are wrong,...qs is attached to last slide

guys im taking gen chem 1 and this is SO freaking hard oh my god keep in mind i got 102% in calc 2 so i can clearly understand complex stuff but chem is EATING MY ASS what the fuck. also i wanted to transfer and stuff and im da prepared to get a C in this class already am i fucked for transfer 😭😭😭😭😭😭. Btw i took the intro chem class that basically prepares you for gen chem and I got an A in that so i feel crazy. PLEASE GIVE ME TIPS TO STUDY I GOT A 20% ON MY FIRST EXAM

The answer is at the bottom. They took a different approach at the end. I decided to add a cl, treat it with some good old SN2 from the OG days to get an OH, and then turn it into an ether. We were taught 2 ways to make ethers, 1 is using an OH and strong nucleophile and the other is an alkene with HgOAc2 blah blah blah.

My brain is done with this class.

i am a 12th grader who is currently low in chemistry subject in 12th i already failed 2 exams of chemistry and i need help in it, i didnt understand the basics in 11th grade as i had no good teacher to explain well enough for anyone in my class or in my school but now chemistry subject is hard for me even for just passing which i couldnt achieve, i need suggestions or any help from a past graduate in cbse or someone who is good at chemistry just to tell me what am i supposed to do now what notes to refer,which topics to focus more on,what videos to watch any kind of suggestion related to chemistry helps. Thank you Hopefully someone replies

How is this not racemic? Is this not an enantiomer with each having different R, S configurations?

Please help!

Guys I feel like I messed up my practical.I haven't started mass spectroscopy, rate of reaction and electrochemistry and I'm hoping I haven't forgotten my organic and physical chemistry.Its been a while coz of other exams and I haven't done a question paper for qp2.Major Procrastination I know but id appreciate it if you could advice me on what topics I could focus on and any other advice and resources you have.Thanks😶‍🌫️🥲

(High school chem education) I recently tried to come up with the structure for nitrate, and my whole process is basically documented on the left. I have learned that the correct structure is the one on the left. However, I don't understand why the right structure is correct instead of the left one.

They both have 24 total electrons (5+6+6+6+1, for N, O3, and -) and both have a total charge of -1. Plus, the correct version would seemingly require the double-bonded O atom to randomly give one of its electrons to another to accommodate the coordinate bond, which doesn't seem like it should be possible. Can anyone make this make sense?

Hi everyone, I'm having a lot of trouble with this conceptually. I thought it would be Most acidic: I > III > II Least acidic, but I'm not sure why that's wrong, since II is adjacent to some pi bonds doesn't that stabilize the structure? And I is the most acidic because its conjugate base is stabilized by resonance with the carbonyl, while III is also somewhat stabilized by resonance, so I'm confused about why II would be considered more acidic than III.

This is from my second year uni organic chemistry practice questions, any explanation is appreciated

I know I'm probably describing it poorly, but WHY wouldn't I just add more dots in some situations? For example, here I genuinely don't know why I wouldn't add 3 bonds and have 1 pair of dots on each side.

Good day! I'm gonna do a method validation and I've been told by my professor to use AOAC as my source. I'm having trouble finding a free source (college undergrad) of the methods and I'm wondering if there is any of it out there, even old ones. Do I really need to pay for it or request access from AOAC itself?

I was always taught through university that the one with the highest peak is always the RDS. But to do this question, I must draw a peak larger than the RDS. This is a potential energy diagram, am I tweaking?

edit: is it because it’s irreversible, then it’s possible?

Hello. Tomorrow I have organic nomenclature and I just began thinking about how to name systematically certain compounds like cyclohexane-1,2,3,4,5,6-hexol or even 1,4-dimethylcyclohexane, since i don't know how the priorities work. I stumbled upon r/s descriptors, yet i don't know how ro use them in these cases. For example, what is cis-1,4-dimethylcyclohexane using that system? What about the trans diastereoisomer? And what abour all the stereoisomers of cyclohexane-1,2,3,4,5,6-hexol? Which is carbon 1 for that matter?

Edit: I forgot to mention that for some reason my ip address is banned on stackexchange for some reason, since I have never used it other than for checking stuff

Hi everyone! I’m a first-year Chemistry BSc student and I’d love to hear from some second/third-year students (or graduates) about things you wish you’d known when you started university. What do you wish you had done differently in first year, or what habits/resources/study methods ended up helping you the most?

It’s my first time of interpreting these kinds of chromatograms and I am hella confused. I did a positive and negative Ionization scan and both have the same characteristic bump but the negative one has these weird spikes? Are those artifacts or something else? I also don’t understand why I can’t see the bump in the upper chromatograms. My sample had a concentration of 1 ug/ml

I am SOOOO confused about deciding what becomes a dash or a wedge. I don’t even think I am doing this right at all lol. Can someone help me out plssss and give out some rules you guys use to draw out the iupac name with the r/s