CHEMISTRY COMMUNITY

Frederick Keith_4C

What is the list of strong bases and weak bases that I have to memorize??

Frederick Keith_4C

What is the list of strong acids that I have to memorize? Weak acids too?

Frederick Keith_4C

What exactly is the relationship between Ka, pKa, and pH? I don't understand how to calculate them or what they mean either... Someone please explain before the final tomorrow morning ;-;

Frederick Keith_4C

When do I use the terms ferrate and cuprate instead of just iron and copper??

Frederick Keith_4C

How come the pi bonds don't have hybrid orbitals? Like why are they all in the p-orbital? And can sigma bonds exist in atomic orbitals too or do they have to be in hybrid orbitals?

Frederick Keith_4C

What the heck is the chemical formula for this thing even? On the sheet posted on Lavelle's website, it just has the drawn structure, and I don't really understand o-chem shorthand...

Frederick Keith_4C

I know amphoteric means a compound can act as an acid or base, and amphiprotic means that the compound can both donate and accept a proton. So my question is what exactly is the difference between these two definitions? Don't they essentially mean the same exact thing?

Frederick Keith_4C

I understand that strong acids are fully ionized and weak acids are only partially ionized in solution. I get that, but i don't understand how to identify a strong or weak acid. Is there like a list of strong or weak acids that I can just memorize for the final? Or is there a rule of thumb that I'm ...

Frederick Keith_4C

If the scale is 0-14, how come some acids and bases have pHs beyond the scale? Like how is it possible to get a negative pH or a pH above 14 if the scale is 0-14? Why don't we change the scale to accommodate those acids and bases?

Frederick Keith_4C

I understand that an amphoteric compound is one that can act as both an acid and a base, but I don't know how one can identify one. So my question is how do you identify an amphoteric compound??

Frederick Keith_4C

The compound is : [Co (NH3)3 (H2O)3]2 (SO4^-2)3 The ligands are ammonia and water. The name is Triaminetriaquacobalt (III) sulfate How come its only "tri" when there is a 2 subscript? Shouldn't they all be multiplied by 2 and the name should have prefixes for "six" instead of &qu...

Frederick Keith_4C

I already asked what the roman numeral represents, but this time I'm asking how do you find it?
For example, if the compound was [Co (NH)3 (H2O)3]2 (SO4^-2)3 what would the name and roman numeral be?

Frederick Keith_4C

I see roman numerals in a lot of the coordination compounds, and I don't know what it represents. So my question is what do the roman numerals represent or mean?

Frederick Keith_4C

The name of the compound is just written out with the substituents in alphabetical order followed by the base name. Here are some examples: 1) 4-ethyl-2-methylhexane (the e in ethyl comes before the m in methyl) 2) 2,3,5-trimethyl-4-propylheptane (don't look at the number prefixes when naming. You l...

Frederick Keith_4C

Bronsted acids accept protons and Lewis acids accept electrons.
Bronsted bases donate protons and Lewis bases donate electrons.

Frederick Keith_4C

Cisplatin binds the two strands of the cell's DNA (genetic material) together, and it can't be replicated. If the strands are permanently binded together then DNA helicase won't be able to split the strands and DNA polymerase wouldn't be able to add complementary nucleotides to the lagging and leadi...

Frederick Keith_4C

A head-on overlap is formed by sigma bonds. Pi bonds are able to form side-to-side overlaps. Which is why sigma bonds are stronger than pie bonds Sigma bonds are stronger than pi bonds because the atomic orbitals forming the sigma bond overlap greater than in the pi bonds. Thus, greater overlap mea...

Frederick Keith_4C

A sigma bond is a covalent bond which is formed by the head on overlap of two atomic orbitals. A pi bond is a covalent bond which is formed by the side to side overlap of two atomic orbitals. You can't just say an overlap of orbitals because sigma and pi bonds overlap in different ways, unless you'r...

Frederick Keith_4C

If there were only two bonded atoms and no lone pairs of electrons, then the electron arrangement would be LINEAR. But if there were two bonded atoms AND lone pairs of electrons, then the electron arrangement would be BENT or ANGULAR. This is because the repulsive nature of the lone pair electron is...

Frederick Keith_4C

They're basically the same thing. Its just that that chloride is the newer variant and chloro is the older one. I'm pretty sure Lavelle said you could use either one and still be chill.

Frederick Keith_4C

I know bonds and lone pairs count as regions of electron density, but does a single electron by itself also count as a region of electron density?

Frederick Keith_4C

Hi I know that VSEPR theory and IM forces are gonna be on the test, but is hybridization gonna be on the test too??

Frederick Keith_4C

Literally what even is hybridization and why is it important?
Also for an "sp^3 orbital" is this 4 orbitals put in one?
Like one s orbital and 3 p orbitals?
Or is it just one orbital and its 1/4 s orbital and 3/4 p orbital?

Frederick Keith_4C

Why are sigma bonds stronger than pi bonds in general??
I read something about overlapping and stuff but it still isn't making sense in my head as to why that makes it harder to break.
If someone could explain the topic to me as if I were a child, that would be absolutely phenomenal.

Frederick Keith_4C

I understand that linear electron arrangements have 2 atomic orbitals, trigonal planars have 3, tetrahedrals have 4, and trigonal biyramidals have 5. But why do octahedrals only have 6? Doesn't octa- mean 8? So how come it isn't called a hexahedral or something?
I am definitely missing something...

Frederick Keith_4C

I see that the strengths of repulsion are in order if lone pair-lone pair > lone pair-atom > atom-atom, but I don't really understand why this is the case. Why do lone pairs have a more strongly repelling effect compared to bonded electrons? If could someone could explain this to me, that would be g...

Frederick Keith_4C

What is the difference between a regular covalent bond and a coordinate covalent bond??? And what is the significance of it?
Like are the presence of these types of bonds integral to life as we know it?

Frederick Keith_4C

A single bond is made up of only one sigma pond.
A double bond is made up 1 sigma bond and 1 pi bond.
A triple bond is made up of 1 sigma bond and 2 pi bonds.

Frederick Keith_4C

Hydrogen bonding is a type of electrostatic attraction between a hydrogen atom that is covalently bonded to another atom that is more electronegative than itself, particularly those of the second period: Fluorine Oxygen Nitrogen Hydrogen bonds are typically weaker than ionic and covalent bonds, but ...

Frederick Keith_4C

A dipole moment is the mathematical product of the separation of the ends of a dipole and the magnitude of the charges. So a polar molecule will have a dipole moment with an arrow pointed towards the more electronegative atom. And a nonpolar molecule won't have a dipole moment. Polar molecules must ...

Frederick Keith_4C

Polarizability is a measure of how easily distorted an electron is by an electric field. Larger atoms with smaller negative charges are easily polarizable and can have stronger Van Der Waals interactions.

Frederick Keith_4C

Polarizing power is related to cations and their ability to attract the valence electron shell from a nearby anion. The tendency for an anion to become polarized by a cation or how easily its electron cloud is distorted is known as polarizability. Smaller, more positive cations can pull electrons mo...

Frederick Keith_4C

N2O has 16 total valence electrons across all its atoms. And we can draw it three different ways. 1) N=N=0 (left N has 2 lone pairs (4 e-) and right O has 2 lone pairs (4 e-)) 2) N-N(triple bond)O (left N has 3 lone pairs (6 e-) and right O has 1 lone pair (2 e-)) 3) N(triple bond)N-O (left N has 1 ...

Frederick Keith_4C

Dissociation energy is defined as the energy needed to break every chemical bond in a molecule and completely separate all of its atoms. This bond-breaking process is endothermic as it requires an input of energy to do so, and will always result in a positive number.

Frederick Keith_4C

Shorter bonds (double and triple) are characteristically stronger than longer bonds (single).
The reason for this is because the additional bonding electrons attract the nuclei more strongly and pull the atoms close together, shortening the bond length.

Frederick Keith_4C

I don't think its really a matter of electrons being pulled in or away from. In general, neutral atoms have spherically symmetric arrangements of electrons in their electron clouds. But in the presence of an electric field, they can get distorted. Polarizability is a measure of how easy that distort...

Frederick Keith_4C

A formal charge is the charge assigned to an atom in a molecule, assuming the electrons in a chemical bond are shared equally between the atoms. You know how to calculate it, but the purpose of it is to determine which of the Lewis structures it the most stable/correct. The lower the formal charge, ...

Frederick Keith_4C

Why double and triple bonds have shorter bond lengths than single bonds?? Also is it possible for an element to form a quadruple bond???

Frederick Keith_4C

I think I kind of understand how to write or find the electron configuration of a neutral atom, but I'm kind of confused as to what changes in the configuration once the atom gets charged and becomes an ion. Do i just add an electron when forming an anion? and do I just remove an outermost electron ...

Frederick Keith_4C

Resonance is when some Lewis structures have multiple bonds with the same chemical connectivity but the electrons are distributed differently around the structure. So my question is what does it say about a molecule or compound if it can form multiple different resonant structures??? For example, if...

Frederick Keith_4C

Resonance is when some Lewis structures have multiple bonds with the same chemical connectivity but the electrons are distributed differently around the structure. So my question is what does it say about a molecule or compound if it can form multiple different resonant structures??? For example, if...

Frederick Keith_4C

So to my understanding, the inert pair effect is when an element forms a a compound with a valency two lower than the expected group valency. In group 13, Al forms Al 3+ ions but In can form In 3+ and In + ions. I don't really understand why this happens? I think it has to something to do with the s...

Frederick Keith_4C

Why is ionization energy always positive????? And I understand that the second ionization energy is always larger than the first, but that can be said for every other electron removed thereafter. So my other question is how many ionization energies are typically calculated or found for each element ...

Frederick Keith_4C

So the electron affinity of an element is the energy released when an electron is added to a gas phase atom. So my question is when doing calculations to determine the electron affinity of an element, what is the difference between a positive and negative electron affinity? What do they mean?

Frederick Keith_4C

If 2 electrons are paired then they have opposite spin and if 2 electrons are parallel then they have the same spin. But how do you know if the electrons are paired or parallel when writing out the electron arrangements given only and element's atomic number principal energy level? For example, if I...

Frederick Keith_4C

I'm still confused about electron spin... So my question is what would happen if two electrons with perpendicular axes approached each other? I kind of get what would happen if they approached each other in parallel and anti parallel, but the perpendicularity is really messing my brain up...

Frederick Keith_4C

I've heard that electrons don't really spin and that the spin number has nothing to do with actual physical spinning, so if they aren't then what exactly are they doing??? Sure they spin around axes and such, but are they going around in clockwise and counterclockwise directions? Someone please expl...

Frederick Keith_4C

The angular momentum quantum number (l) describes the "shape" of the orbital that an e- occupies. The lowest possible value it can have is 0 and the highest value it can have depends on the principal quantum number, n-1. For example, an s-orbital is associated with an l=1, p-orbital with l...

Frederick Keith_4C

My high school chemistry class was really bad, so we never wrote any electron configurations and I've been a little confused. I understand that when writing them you should write in order from lowest to highest energy, but I don't understand the short hand configurations. For example, Calcium was wr...

Frederick Keith_4C

Shells are composed of e- that share the same principal quantum number (n),
Subshells are composed of e- that share the same angular momentum quantum number (l)
Orbitals are composed of e- that are in the same energy level but have different spins (up or down).

Frederick Keith_4C

Yes basically what the other guy said but in other words: The frequency stays the same because as a wave travels into a denser medium, it slows down and the wavelength decreases, so the proportion or ratio between the two is going to stay the same.

Frederick Keith_4C

Yeah just to add on, the speed of light does change when passing from medium to medium. But the fastest it can be is the value we denote as "c" (3.00 x 10^8 m/s), which is when it is travelling in a vacuum.

Frederick Keith_4C

The speed of light can misleading because the value we use is light as observed in a vacuum (3.00 x 10^8 m/s), but the speed of light is not the same as it passes from medium to medium. When it enters a denser medium (from air to glass for example), the speed and wavelength of light decrease while f...

Frederick Keith_4C

Atomic spectroscopy refers to the study of electromagnetic radiation as absorbed an emitted by atoms, and molecular spectroscopy is the same thing except instead of having atoms you got molecules. Spectroscopy has a ton of applications and you can study the structures of atoms and molecules. Because...

Frederick Keith_4C

Diffraction is basically just the bending of waves around an obstacle or through a slit. I think everyone has already covered the topics of constructive and destructive interference fairly well, so to further elaborate on the topic, I'll just provide some examples of diffraction. Ex 1) the spaced tr...

Frederick Keith_4C

The equation is E=-hR/n^2 h is Planck's constant (6.62607004 × 10-34 m2 kg / s) R is Rydberg's constant (10 973 731.6 m-1) n is the energy level You use this equation when you're trying to find the energy of whatever n energy level. So for example if an electron transitioned from n=4 to n=2, we woul...

Frederick Keith_4C

The properties of light being explained as a wave was shown in Young's double slit experiment. In the experiment, a beam of light was split into two beams through two slits and then recombined, and interference effects were displayed. If light was simply a classical particle then the expected patter...

Frederick Keith_4C

Another way to think about what is MI VI and what is M2 V2, you can think of the first set of variables as your stock solution (before dilution) and your second set of variables are a part of your desired solution (after dilution).

Frederick Keith_4C

No you can only have limiting reactant in a reaction. Every other reactant is in excess. Once the ONE limiting reagent is completely used up, the particular reaction can no longer occur because the amount of product formed is limited by the limiting reagent. This is the case even if there is plenty ...

Frederick Keith_4C

Yeah you can just multiply by 1000 like straight up.
Like if we got 0.0027 kg of oxygen, you can just be like:
(0.0027) (1000) = 2.7 grams of oxygen
Or you can just move the decimal around like we did in elementary school if the mental gymnastics are messing with your head.

Frederick Keith_4C

A limiting reagent is just a reactant that limits the amount of product formed in a chemical reaction. You can determine what is the limiting reagent by comparing the mole ratio of the reactants used in the reaction. Here are some steps: 1) Balance the chemical equation given if not already balanced...

Frederick Keith_4C

Our first test begins on Tuesday (10/8/19) for those who have discussion block then and it will continue on for the rest of the week. So whenever your discussion is is when you will have your test. You have 50 minutes to do it, and it covers topics such as empirical and molecular formulas, balancing...

Frederick Keith_4C

Aight chieftain, here's what you do. You're working with decimals, but we wanna work with fractions when we're calculating ratios. So basically, what you wanna do is take your decimal answer and just convert it to a fraction and then multiply by the denominator. If you got a TI-84, just go MATH --> ...

Frederick Keith_4C

They're all correct. The first one is probably correct because the TA says so lmao :P The second one is correct because its referring to its empirical formula. It often gets confusing however because many people leave off the di- prefix. The third one is the most intuitive because there are 4 phosph...

Frederick Keith_4C

Alright so I was in the shower listening to Weezer, and this thought came into my head. To start a fire, in a typical combustion reaction, you need a reaction to occur between a fuel and an oxidant. And the oxidant is typically atmospheric oxygen, but there is no oxygen in space, so literally why is...

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