CHEMISTRY COMMUNITY

Sam Metzger 1C

Yes. Acids and bases neutralize each other in a titration, which results in the formation of a salt and water.
Example: HCl + NaOH yields H20 + NaCl. In this case, a strong acid, HCl, and a strong base, NaOH, cancel each other out and form salt and water in solution.

Sam Metzger 1C

Yes, you would essentially disregard the Na+ ions because they have no effect on the pH of the solution. In the aqueous solution the only things reacting and contributing to a change in pH are the C6H5O and H2O.

Sam Metzger 1C

I'm not sure if there is any kind of short cut to calculating the formal charge but all group 17 atoms have a formal charge of 0 when they only have one shared bond & six lone pair electrons and all group 16 molecules have a formal charge of zero when they have two shared bonds & four lone p...

Sam Metzger 1C

Any disparity in charge is higher in energy. If, for example, a neutral molecule has one atom with a +2 formal charge and another with a -2 charge that would be a higher energy molecule than if the formal charges of the atoms were 0.

Sam Metzger 1C

Yes, the unequal sharing of electrons implies polarity. In addition a non-polar covalent bond can still have an induced dipole creating a moment of polarity that makes the intermolecular force stronger. Large carbon based molecules, for example, have very strong intermolecular forces because there a...

Sam Metzger 1C

Right, elements that can break the octet rule (that we'll be looking at at least) are in n=3 shell or below and in the p block. Sulfur, Phosphorus, Chlorine, elements like these can break the octet rule. As for radicals, if the total valence electron count is an odd number, there is likely a radical...

Sam Metzger 1C

As a general rule, group 13 elements have a charge of 3+. But it may be more useful to think about their bonding in the sense that they often make three bonds, such as BF3, which bonds with another atom or molecule to form a larger compound.

Sam Metzger 1C

Yes, it's also important to note that for example the ml values (1,0,-1) for p do not necessarily correspond to px, py, and pz in that order. The order of the orbitals doesn't matter the only thing that does is how many electrons are in each one.

Sam Metzger 1C

Once an electron is in the 3d sub shell, it is lower in energy because the 3d electrons are in the n=3 shell and 4s electrons are in the n=4 shell. As a result, the 3d electrons are listed before the 4s electrons when writing out configurations.

Sam Metzger 1C

Exactly. For any element with electrons in the d sub shell, those electrons will be listed first. Even though, 3d and 4s electrons are in the same row of the periodic table, for example, the d electrons are in the n=3 shell and would be an entire shell closer to the nucleus than the 4s electrons.

Sam Metzger 1C

Yes, the electron configuration for Fe 2+ would be 3d^4 4s^2 because there are two fewer electrons in an Fe 2+ ion than there are in a regular Fe atom. And yes, ground state carbon is 1s^2 2s^2 2p^2 because there are six total electrons, two in each subshell. There would only be two unpaired electro...

Sam Metzger 1C

Exactly, you are allowed to shorthand the electron configuration starting at the largest shell or n value.

Sam Metzger 1C

The electron configuration for Br- would be [Br] 4s2 3d10 4p6 and not [Kr] because with an extra electron the Bromine atom does not become Krypton. It would retain the same number of protons but just have an extra electron.

Sam Metzger 1C

Yes, unless we're talking about the uncertainty of a different particle.

Sam Metzger 1C

The equation essentially tells us if a particle is present within a certain range of position. Recall the example from class where the equation proved that an electron cannot be inside the nucleus of an atom (of course we knew that already but the Heisenberg Indeterminacy equation is one way to prov...

Sam Metzger 1C

For this problem, the kinetic energy is zero so the energy of the photon would equal the work energy. From here, we can find the wavelength by using the equations E=hv and c=v(wavelength) and solve for the wavelength.

Sam Metzger 1C

When light acts as a particle/photon as in the photoelectric effect, the intensity does refer to the amount of photons. The significance is that there is a 1:1 ratio between photons and ejected electrons (with sufficient frequency). So, if we double the intensity of the light, we'll have twice as ma...

Sam Metzger 1C

Photons do not have a REST mass, which is another criteria for the equation to stand. Although a photon may have p, because they don't have a rest mass they do not apply to the De Broglie equation.

Sam Metzger 1C

Spectroscopy explains why different materials are different colors. For example, transparent materials don't absorb any light and hence are clear, and black substances absorb basically all the photons that are sent their way. (This is why on a hot day you feel hotter in black.)

Sam Metzger 1C

Exactly. It's also important to note that this value is the speed of light in a vacuum. We'll probably be able to use this value for all our calculations but it would be a different number in another medium.

Sam Metzger 1C

Right, the classical model is shown by the physical wave (like in the ocean for example) with the intensity determined by amplitude. The taller the wave, the greater the intensity. Then with the photon model in quantum mechanics, the intensity of the photon is determined by the amount of them. Then ...

Sam Metzger 1C

1) Right, because a photon is a wave particle its energy is absorbed by an electron which gets "excited" and jumps to the next energy level. 2) Once the electron has absorbed the energy from a photon and jumped an energy level, it returns to its original state. This process releases energy...

Sam Metzger 1C

The introduction of a catalyst does NOT change the chemical equation. The catalyst only assists in a reaction by lowering the activation energy and making the reaction happen faster. In the one step equations we are looking at the catalyst is not included in the reaction.

Sam Metzger 1C

With combustion reactions, it is always helpful to balance the Carbons and Hydrogens first and the Oxygens last. Because the oxygens are usually the most abundant and present in both of the products, finding the balanced number of hydrogens and carbons first makes the number of oxygens easier to cal...

Sam Metzger 1C

Because HF is an acid, we can assume it is aqueous with the ions dissolved in water. This reaction produces a gas, SiF4 (silicon tetrafluoride) and liquid water.

CHEMISTRY COMMUNITY

Search found 25 matches

Re: Acid and Bases [ENDORSED]

Re: Writing the chemical equation for proton transfers

Re: Formal Charge Shortcut

Re: Low Energy

Re: Polar Covalent vs. Unequally Shared

Re: Radicals/Octet Rule

Re: 3.25

Re: Clarification on magnetic quantum number

Re: 4s orbital

Re: Electron Filling of Orbitals [ENDORSED]

Re: Ground State Configuration

Re: Cl -2

Re: Electron Configuration for Br- (Bromide ion)

Re: Finding velocity (delta)V [ENDORSED]

Re: Uncertainty Equation significance

Re: Post-Assessment #31 [ENDORSED]

Re: Significance of intensity [ENDORSED]

Re: Photons? [ENDORSED]

Re: spectroscopy [ENDORSED]

Re: Value of Speed of Light** (Shoutout to Dr. Lavelle for calling me out in lecture today) [ENDORSED]

Re: Intensity in terms of Quantum Mechanics and Classical Mechanics

Re: Atomic Spectra Electron Emission

Re: Balancing Chemical Equations

Re: H.17 [ENDORSED]

Re: H.15 adding solid, liquid, gas or aqueous to balanced equations [ENDORSED]