CHEMISTRY COMMUNITY

ChristianM3F

So, is this question basically just counting on you to memorize that acids tend to be non-metal oxides, bases being metal oxides, and amphoteric compounds following that diagonal metalloid line of oxides..? Also, if you're reading this, other than the good ol' "H in front of the formula" a...

ChristianM3F

Wait, so could someone please explain to me how BF3 would be a Lewis acid? Would the boron take in the electron pair, even though it'd take on a negative charge..?

ChristianM3F

Can someone please explain why NH3 doesn't act as a Bronsted acid (as a proton donor) when it gives its proton to the OH- that comes from CH3COOH? Gracias in advance!

ChristianM3F

6A1b. Find the conjugate acid for NH2NH2...
So, I'm pretty sure that this base is a polyprotic base, meaning that it can accept more than one hydrogen ion. (Due to the dual lone pairs on dual nitrogens...) Does that mean that another possible conjugate acid for this substance is NH3NH3^2+?

ChristianM3F

J9... Any tips, guys? I'm so lost on how to even approach this problem. Identify the salt that is produced from the acid–base neutralization reaction between (a) potassium hydroxide and acetic acid, CH 3 COOH; (b) ammonia and phosphoric acid; (c) calcium hydroxide and bromous acid; (d) sodium hydrox...

ChristianM3F

J.5B: (CH3)3N (aq) + HNO3(aq) -> Any advice how one would tackle this problem? Or would it just be a strategy in of itself to know that since HNO3 would most likely be an acid (due to the H attached to the front of the formula), it would attach itself as the 4th bond to the Nitrogen of (CH3)3N? Any ...

ChristianM3F

Hmmmm another question, for KOH, it said that it donated a OH- ion, but the textbook said that it only supplied the OH, but didn't specify it as an acid or a base. Does this mean it's not a Bronsted acid/base? And also, the book said that C3H5COOH was an acid. I would've thought that it'd be a base,...

ChristianM3F

Write the chemical equation for a neutralization reaction in which calcium phosphate is produced.
HPO4 + CaOH -> CA3(PO4)2 + H2O
Well, I found that out... I hope this is right. But could I have help balancing it? (Also correct me if the entire equation is wrong HAHA)

ChristianM3F

Which of the following compounds are Brønsted acids or bases in water? (a) KCl; (b) HClO; (c) HF; (d) Ca(OH)2 (a) HNO3; (b) C6H6; (c) KOH; (d) C3H5COOH. ... So, simple question. How does one do this problem? I understand that a good indicator that a compound is a Bronsted acid is having an H at the ...

ChristianM3F

Woah, so CO32-, also known to others as carbonato-(curvy K)O can be used as a bidentate? I didn't know that, since that was never mentioned in the table we've been using...
So how do we know whether a ligand is a polydentate, and how many bonding sites there are..?

ChristianM3F

And yeah, so why does 9C.3d suddenly disobey the nice alphabet rule..? The parantheses are there, so I'm guessing there's a reason why that happened...

ChristianM3F

Yeah, so I know that there's a rule that when naming a coordination compound, you name the ligands alphabetically with no regard to the numerical prefix.
However, I've made it a habit to always alphabetize the ligands when writing out the compound formula too. Would this be correct..?

ChristianM3F

Wait, so what? Chelating? What does that have to do with structure, again..?
Someone please help... Ty :)

ChristianM3F

So the overall charge of the molecule would be given... right?

ChristianM3F

Ok, I'm just trying to make sure I'm doing this correctly. Pls don't judge So like, for the first daNg step, when it says to add the overall charge, how would you find it??? Let's just use [Fe(NH3)5(OH2)]3+ as an example. I know that the ammine ligands have an overall charge of 0 (...right?) and so ...

ChristianM3F

ALSO YIKES I DON'T SEE THE SOLUTION IN MY MANUAL TO THIS PROBLEM. The question regards the second carbon that's pi-bonded to the nitrogen, along with a lone pair. If an atom has two electron-dense regions, and one of them happens to be a lone pair, does that mean the atom is still linear..? I'm hopi...

ChristianM3F

So for VSPER, when dealing with radicals, do we account for singular electrons as electron dense regions? For example in CH2+, since the Lewis structure has two bonds, one lone pair and a single electron to the carbon, are there three or four electron dense regions? Will the lone electron affect the...

ChristianM3F

A neutral atom? If you determine its formal charge, you'd use the equation (5-(2+6/2), which would equal 0.
I'm guessing you're meaning non-polar or polar, and I believe that it is polar, since it's a tetrahedral molecule that doesn't have the same 4 atoms bound to its electron-dense regions.

ChristianM3F

idk why this didn't post!!! A see saw model would have 5 dsp3 orbitals (since there are 5 electron dense regions). However, since one of those regions needs to be a lone pair, the central atom would have 6 electrons to work with. 5 of those electrons would fill the 5 orbitals, and the 6th would fill...

ChristianM3F

I don't think it would be applying a "cis" structure to a molecule..? Correct me if I'm wrong, but you'd probably determine if a molecule had a cis or trans structure based off of clues of the molecule. If the molecule had a higher melting or boiling point, it'd probably cis. Likewise, if ...

ChristianM3F

A molecule's VSEPR model would be seesaw if the VSEPR equation was AX4E1, while the equation would be AX5 if it was trigonal bipyramidal. A t-shape VSPER model is only acquired when there is 5 electron dense regions, but with 2 lone pairs in the mix. The VSPER equation would be AX3E2. A tetrahedral ...

ChristianM3F

So, because different atoms have different sizes, the angle is never truly/exactly 109.5 degrees unless all 4 atoms surrounding the central atom are the same. However, this phenomenon has a much smaller impact on bond angles than the presence of a lone pair, since lone pairs are untethered at one e...

ChristianM3F

Update!
Yeah, so the bond angles for COF2 (according to the book, at least) came out to be 120 degrees. They left out "approximate" in their answers too.
So, yeah, what the heck, chemistry divinities?

ChristianM3F

For 2e15a, it gives CF3Cl, a tetrahedral molecule with 3 flourines and a chlorine attached to a central carbon atom. However, it did say to approximate the bond angles, and gave an approximate bond angle of 109.5 degrees (the bond angle for a tetrahedral molecule.) So, is that the case for tetrahedr...

ChristianM3F

Thanks! I should probably try doing that as well.

ChristianM3F

Yeah, hi, just wondering if anyone would give any tips on how to draw the Lewis Structure for the chemical compound mentioned in 3F1c. H2SeO4... The problem never asked for the Lewis structure, but I'm just asking out of curiousity's sake:) (and plus, it'd probably really help to find the solution, ...

ChristianM3F

Wait, so resonance only counts if you shift the bonds around? Not the lone pairs..?
Then what if you shift bonds around, but have to move the lone pairs to account for the shift..? If that makes sense..?

ChristianM3F

There aren't many homework problems I've seen that makes me cry. But upon seeing a monstrosity like this problem, I guarantee that if I attempted doing the problem before the midterm, I would burst into tears. If anyone's done this problem, any suggestions on how to start a problem like this? Strate...

ChristianM3F

So, resonance structures! At its essence, merely chemical models (or, in even simpler [but probably inaccurate, so feel free to correct me] terms, just combinations of bonds/lone pairs around the elements. However, if we have a combination that matches the expected charge (yknow, like if BrO+ has th...

ChristianM3F

Restrict rotation..? I don't think I get what you mean, but I do believe that if you're talking about the electron's rotation around the atom, a double bond would restrict that electron's movement since the double bond would be a lot stronger than a regular, single bond. Therefore, your electron's r...

ChristianM3F

... Ok, I think I see what's happening here.
But I tell chemistry jokes all the time too,
But I get no reaction. :(

ChristianM3F

Just out of curiosity, since we just took the midterm, when the test says "list all formal charges," would it be fine/acceptable just to write the formal charge next to each atom in a Lewis structure? It'd take a long time to list out the calculations for each atom in the Lewis structure...

ChristianM3F

Also, so if the expanded octet rule would be limited by the space in the d/f orbitals, would that mean: -elements in the p-block on period 3 can have an expanded octet of up to... ten electrons..? -elements in the d-block on period 4 can have an expanded octet of up to 10-how many electrons are in t...

ChristianM3F

Yes, the closer up and right on the periodic table an element is, the more electronegative it is (I believe the most electronegative element is Flourine..?) But I remember hearing in either a peer learning session or in class that there is a pattern other than electronegativity where the pattern isn...

ChristianM3F

Yes, the closer up and right on the periodic table an element is, the more electronegative it is (I believe the most electronegative element is Flourine..?) But I remember hearing in either a peer learning session or in class that there is a pattern other than electronegativity where the pattern isn...

ChristianM3F

So, the solution for the structure of BrF3 had bromine not form an octet...
So is it a rule that, if they give you a chemical formula and tell you to make a Lewis structure, it's ok for the central atom to not have an octet? I think I just need to know the exceptions to the octet rule in general.

ChristianM3F

Hi, I'm struggling to comprehend/understand the answer given in the solutions manual for this question. In 2A9a, it says to find what metal (M2+) in its ground state configuration, has the electron configuration of [Ar] 3d7. Is this just asking "which element has the ground state configuration ...

ChristianM3F

Quick question, chem community. With the midterm around, just to make sure I won't get marked off for this, but in this case... If I ere writing the electron configuration of say, Titanium, would [Ar] 4s2, 3d2 be incorrect? Is [Ar] 3d2, 4s2 the only correct answer, or does the order of the orbitals ...

ChristianM3F

Can someone help me understand the solution for 1.31? I have no idea where they got the equation/values used to calculate E (work function). The only way I know how to calculate work function is using the amount of light energy and the kinetic energy of the electron that's ejected, so I'm majorly co...

ChristianM3F

Ok, so the solutions manual explained why oxygen has a lower ionization energy than fluorine and nitrogen, and basically said that since oxygen is the first element encountered in which the p-electrons must be paired. So if it's based on p-electrons being paired creating repulsion energy, then why w...

ChristianM3F

In question 1f21, it asked us to identify which elements were metals, metalloids and non-metals. It's pretty easy to figure out which elements are metals (as most, if not all elements in the s-block and most of the elements in the d block are metals). However, does anyone happen to have any tips for...

ChristianM3F

Ok, weird question, yet again. So, for the buildup principle, (and Hund's rule), it dictates that electrons must be placed in parallel spins in different orbitals within a subshell if there are more orbitals available. So, Carbon for example, would have a configuration of [He] 2s^2, 2p^2... But in r...

ChristianM3F

Wait if you're reading this, i re-read the textbook, and penetration didn't mean what I think it meant. If you're still down to explain it, go ahead, I guess..?

ChristianM3F

Hello, chem community, just slowly working through these chem problems! As seen in 1E5: "Electrons in an s-orbital are more effect than those in other orbitals at shielding other elctrons from the nuclear charge because an electron in an s-orbital can penetrate to the nucleus of the atom."...

ChristianM3F

Hi, probably another quick question, but when building up the ground state configurations for all the elements, would the order in which orbital would fill first matter? For example, for Carbon with atomic #6, would the final buildup be acceptable as 1s^2, 2s^2, 2p x ^1, 2p y ^2, 2p z ^1 be acceptab...

ChristianM3F

I was looking through my notes, and I wanted to confirm something really quickly. [Please also let me know if anything is WRONG about what I'm about to say.] So, nodal planes are basically regions of an atomic orbital where an electron has a 0% chance of being in that region. But for each atomic sub...

ChristianM3F

Ok, so I was reviewing some of my notes I took in lecture, and I came across a note that I don't remember understanding. "According to the Heisenberg principle, there is a limit to the minimum size that atoms must exist, based on physical parameters of electron mass, i.e c) This was when we pro...

ChristianM3F

So, when covering the equation delta(E) = h (nu), and thereby converting the equation to nu = delta (E)/h, Dr. Lavelle states that when nu (the frequency of light) matches the "energy difference" of the electron, absorption of the light wave occurs. For me, this is the single biggest quest...

ChristianM3F

Wait, so ok. c = wavelength * frequency... But, if we say that c = the speed of light, how come this velocity equation applies to all of the types of waves on the electromagnetic spectrum? If c really did equal the speed of LIGHT, how come the equation applies to like, microwaves and x-rays? oh my [...

ChristianM3F

Hi, chem community! I posted a question earlier about the v = wavelength * frequency being applicable to all waves/electromagnetic radiation... But since that's true, why would part (a) or 1A3 be "no, speed is constant?" If the frequency of the radiation would decrease, according to the eq...

ChristianM3F

Hello, quick question Chem community! So, when dealing with the speed of light, the equation for that would be c = wavelength (lamda) times... uh that curvy V thing for frequency. And c would be the velocity of light. But would that equation be applicable for finding the velocity of other waves..? L...

ChristianM3F

... as someone who's never taken chemistry, and definitely has never heard of solubility rules and forming net ionic equations, will we need to know this before the test tomorrow? Or will we be tested on it specifically when we've covered (or at least brushed up on) the material in class?

ChristianM3F

Hi, I tried completing M9, and with my lack of knowledge behind chemical nomenclature, I searched up the molecular formulas of copper (II) nitrate, sodium hydroxide, and blue copper hydroxide. And I checked the solutions manual, and the equations (and even the molecular formulas used) were completel...

ChristianM3F

Hi, so during the test, does anyone know if we're graded on including the matter (s) for solid, (g) for gas, etc in our work? A quick question but I wanted to get it out of my head so I could keep studying...

ChristianM3F

Thanks, but how did you get 100 g / 37.5 g of HCl? I know it has something to do with the percentage of HCl, but I'm still trying to wrap my head around why it would be 100/37.5 and not 37.5 grams of HCl / 100 grams of other substance.

ChristianM3F

Hi, Chem Community... So, upon looking at G27, which was done in our discussion groups (and I'm guessing it's within the homework problems), I'm trying to translate the solutions done into the one equation Dr. Lavelle was simply using in his video lecture. n(initial) = n(final) M (initial) * V (init...

ChristianM3F

Quick question about E15... Am I missing something here? They ask what the molar mass of the sulfide in M(OH)2 is, but doesn't a sulfide need a sulfur molecule? (Chemistry's hard...

ChristianM3F

Well, I think this is sort of related to significant figures, but when you've determined how many significant figures is required in your answer, are you allowed to truncate the answer? (For example, if you need 3 significant figures and you were trying to write out 4.6962, would you be allowed to w...

ChristianM3F

Hello, I'm currently struggling through some of these basic questions! So, in question E9, the first question they ask is how many atoms of oxygen would be found in 5.15 grams of Magnesium Sulfate Heptahydrate. First off, I'm assuming that Magnesium Sulfate Heptahydrate has the chemical equation MgS...

ChristianM3F

Ooouu, thanks for the replies! They really helped. But since it's related to the problem, mostly out of curiosity, what does happen to the excess water left behind in the reaction? Since only 3.12 moles are used out of the 5.55 initial moles, will we just find the leftover 2.43 moles of water mixed ...

ChristianM3F

So, in Dr. Lavelle's lecture, he talks about calculating the limiting reactant or reagent... But he never mentioned how to calculate the amount of moles created in said reaction. For example, in the video, he had the example of CaC2 + 2 H2O -> CA (OH)2 + C2H2. Since we limited our reactants to 100 g...

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