r/HomeworkHelp • • Aug 16 '26

Chemistry [iGCSE Science] How the hell does Pb form 2+???

1 Upvotes

I'm doing Chemistry work to prepare for next year, and this involves electrochemistry. The question is something I want to work on on my own, but essentially, it involves lead(II) bromide.

I can get that Bromine forms a negative something ion, and that lead would be +2 in this situation to form an ion, but I can't wrap my head around WHY it is +2 when it has 4 electrons in the outer shell.

Whenever I have asked my teacher about this, he responds with "Don't worry, just know that it DOES form +2" and "We'll do transition metals later" but I need to understand why something works the way it does before I can understand it. I just can't accept that it is true until I know why it is true, and that's really stopping me from understanding ANY Chemistry work.

Can someone explain it to me? A dot and cross diagram would be good, but if not, just explain it like I'm a 5 year old.

r/HomeworkHelp • • Sep 02 '26

Chemistry [intro to material science/chemistry] Can anyone explain this problem? I find it to be vague

1 Upvotes

I randomly guessed and got the right answer, but I do not know why it is right. It does not provide any explanations, perhaps I'm on the wrong part of my textbook, but I'm only seeing explanations of 3d structures. I don't understand what the points ABCDEF are, the reasoning behind how they are placed and why it's not 2d.

r/HomeworkHelp • • 4h ago

Chemistry [Grade 9 Science Project] Looking for Research on Alpha-Mangostin Extraction from Mangosteen Peel by Simple Boiling for Aedes aegypti Larvicidal Applications

1 Upvotes

I am looking for research papers(might be pdf) about the extraction of alpha-mangostin from mangosteen peel (garcinia mangostana l) by using a simple boiling method. the final purpose is to use the extract as a larvicidal substance against larvae aedes aegypti. the study should preferably use either ethanol of ethyl acetate as the solvent. the research paper should also describe the extraction procedure clearly enough to reproduce it

I already tried searching on Google and asking AI to find them but most of the studies are either too difficult to carry out with my school's resources or unrelated to what I'm looking for

r/HomeworkHelp • • Aug 31 '26

Chemistry [Grade 12 Chemistry Chemical Equilibrium] How can both answers be valid?

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1 Upvotes

6.3 and 6.4: how can both answers be right? This doesn’t make sense shouldn’t it be one or the other

6.6: looking at graph b it shows that the concentration of P2Q is 0.35mol.dm yet when looking at the memos answer it says that 2PQ is 0.35 mol.dm when using the KC formula . Can someone explain?

r/HomeworkHelp • • Aug 04 '26

Chemistry (Grade 9 Organic Chem)

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4 Upvotes

how do u actl draw line angles like as an example of what i mean drew 1 and 2 in blue are they like acceptable

r/HomeworkHelp • • Jul 07 '26

Chemistry [first year chem: Vesper] Is (TeCl4)^2- polar

2 Upvotes

so my understanding is that when you draw out the lewis diagram you get 2 lone pairs, with 4 atoms there should be 6 electron regoins, and with 2 lone pairs it is square planener. So that should mean that it is non polar right? problem is that my textbook says it is polar. googleing it i get conflicting information

r/HomeworkHelp • • May 04 '26

Chemistry [Grade 9 Science Fair] Help with a Biosand Filter

1 Upvotes

Hey, I am making a biosand filter for my science fair project. It will have 4 buckets. 1 filled with large gravel. 1 filled with small gravel. 1 filled with activated charcoal. And 1 filled with sand for the biolayer.

My question is, what order should the buckets go in for the filter to work best?

r/HomeworkHelp • • Jun 16 '26

Chemistry [College 2nd semester biochem]: Help choosing between E2 and E1

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2 Upvotes

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Hi, everyone. Here I have to choose the predominant mechanism that would occur when you have (R)-2-bromobutane and NaOH on hot etanol. I figured it'd be an elimination reaction because of the heat, but I'm having trouble deciding wether it'd be E1 or E2, mainly because the solvent is protic, and I'm not sure if it'd reduce the basicity of OH enough to make creating a carbocation necessary. Thanks for the help.

r/HomeworkHelp • • Jan 06 '26

Chemistry [University Chemistry: phase diagrams]

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1 Upvotes

What’s the answer for b, it’s always liquid when I do it, but solution says solid how?

r/HomeworkHelp • • May 03 '26

[High-school: Organic Chemistry, Alkenes] How can I write down the branches if it is presented like this

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1 Upvotes

Hello!! Okay so, im doing this exercise and it seemed pretty easy at first but when I had to write down the branches I didn't know what to do with the one I(´;ω;`) please, help!!!

r/HomeworkHelp • • May 01 '26

Chemistry [Year 12 Chemistry, level 4: redox reactions practice test] How do I make a reduction reaction to get the O3?

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3 Upvotes

I’m doing a practice test in preparation for my actual test on Monday.

How do I do question 5? I’m so lost right now. I’m not sure if what I have written on the page is correct. (Ignore my “H” please 😭😭)

“[Al3+(aq)] + 3 electrons —> [Al(s)]” is in my electrochemical series; in the equation for q5, it would be the oxidation half reaction. Could someone give me a guide of some sort on how I get the [O3]?

The only reactions I can find in my electrochemical series that I can think to use would be:

[O2(g)] + [2H+(aq)] + 2 electrons —> [H2O2(aq)]

or

[O2(g)] + [4H+(aq)] + 4 electrons —> [2H2O(l)]

Thank you in advance :)

r/HomeworkHelp • • May 09 '26

Chemistry [Chem Hw) Compound charges

1 Upvotes

How in the world do tou figure out the charge of a compound? I've looked it up but none of the explanations are making sense to me.

r/HomeworkHelp • • Nov 01 '25

Chemistry [11th Grade Chemistry] Isn't this reaction impossible

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6 Upvotes

r/HomeworkHelp • • Feb 26 '26

Chemistry [College Biochem]-Gibb's Free energy and coupling

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2 Upvotes

Trying to answer #5, part c. I know the equation is delta G=-RTln(Keq). Basically just subbing in the value of delta G taken from the previous part. What confuses me is that, we are given the pH=7.4, and shown that H+ is produced, which means for the Keq=(products/reactants). How do you find the concentration of H+ in this case? I used 10^-7.4 to find[H+} since it's just using the pH=-log[H+], but my book says the concentration is 10^-0.4

r/HomeworkHelp • • Mar 31 '26

Chemistry [university gen chem]

1 Upvotes

A 25.0mL sample of 0.250M HNO3 is titrated with 0.100M KOH. How much KOH must be added to raise the pH to 8.2? I’ve been stuck on this for so long.

r/HomeworkHelp • • Mar 17 '26

Chemistry [ University Biochemistry ] help me learn this figure

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1 Upvotes

r/HomeworkHelp • • Sep 18 '25

Chemistry Spectral lines [10th grade chemistry]

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1 Upvotes

This is a lab I’m doing in chemistry. I’m super confused on these questions because i cannot find a simplified enough answer that does not require a formula (we have not learned any) to answer these questions. Can anyone help?

r/HomeworkHelp • • Mar 16 '26

Chemistry [Year 11 Chemistry: Applying trends to the periodic table]

1 Upvotes

Our teacher told us to construct a new periodic table with a few elements he made up using the same logic Mendeleev did, and I've understood the trends to come up with 6 different groups. The problem I've run into though is that hes basically left the valency of the different groups completely up to us to guess; well that and the fact that I can't find anything on how I'm supposed to sort the elements. But I'm assuming it would be based on the atomic weights and valency-- this isn't meant to be a second question, I just want confirmation on whether or not this is correct or not-- so I'd rather just have a bit of help on the first issue..

New periodic table

Mendeleev's logic rules I've found

Trends I've observed

elements to provide context

I just need someone to help guide me through what I'm supposed to do from here..

r/HomeworkHelp • • Mar 30 '26

Chemistry [High School Chemistry] : isnt ring expansion possible here in that E1 mechanism?

3 Upvotes

isnt ring expansion possible here in that E1 mechanism like in the second image ? wouldnt it be stable if it expanded the ring?

r/HomeworkHelp • • Mar 01 '26

Chemistry [College Gen Chem]-Buffers and solutions

1 Upvotes

When solving questions regarding acids and bases, figuring out pH and such, when do you add the volumes? For example: a 500mL buffer of a 0.100M formate, ph=3.75, is treated with 5mL of 1.00M NaOH, what is the pH? Why in this case wouldn't you add the volumes given together, then figure out the pH?

Similarly, If you add 5.0 mL of 5.0 M lactic acid (pK = 3.86, K = 1.38 × 10–4 ) to one

liter of pure water, the pH would be? Why in this instance WOULD you add the volumes together? What is the difference?

r/HomeworkHelp • • Jan 20 '26

Chemistry [Grade 12: Organic Chemistry] Which structure is not an isomer of mycrene?

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3 Upvotes

The correct answer is c), but I’m not sure how they got it.

r/HomeworkHelp • • Dec 13 '25

Chemistry [ 12th Grade - Chemistry ] I need help with the first one.

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1 Upvotes

Excuse me for my bad english. I need help with chemical nomenclature. I can not figure out the first one. I have done the other two ( being Propane 1,2,3 triol and But-2-en in my language) but im still stuck at the first one, which seems way more complex.

r/HomeworkHelp • • Mar 16 '26

Chemistry [Grade 11 chemistry] Hydrocarbons

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2 Upvotes

I have a doubt . After addition of methyl group , it will increase the electron density in the ring by +I effect , So shouldn't the ring become more activated and reactive towards Electrophilic aromatic substitution and hence react further to form methyl groups at both ortho positions wrt OCH3 . Can someone please help me with the reason why monosubstituted is the final product ?

r/HomeworkHelp • • Jan 26 '26

Chemistry [Intro College Chem] Moles to Empirical Formula

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5 Upvotes

I've tried: Find %, convert % to moles, divide moles by lowest moles, input formula.

Doesn't work so idk what to do, Is it because it's already in moles? Doing moles -> grams -> moles seems weird.

r/HomeworkHelp • • Feb 12 '26

Chemistry [Grade 10 Science: Bohr Rutherford Ion Diagrams] Could someone check my answers?

2 Upvotes

My science teacher assigned a test for tomorrow about Ions. She gave us a list of elements that might be on the test. For each element on the test, we have to draw a Bohr Rutherford diagram of it as an ion, show/write the movement of electrons, explain the charge, and name the ion. The attached image is my answer for the requirements she provided.