CHEMISTRY COMMUNITY

mayarivers3I

Jingyao Chen 4H wrote:For #17, what does it mean by the “hybridization of each lone pair”? Is it supposed to be the hybridization of each central atom?

Can someone answer this please! I am wondering the same thing.

mayarivers3I

I don't see the answer key for the marshmallow practice problems so can someone tell me if the answer to 34 is a pH of 2.1?

mayarivers3I

How in depth do we have to know about Kw? I don't remember Lavelle going over it in class. Also, what types of problems would Kw be used for?

mayarivers3I

The question asks us to identify the acid and the base in each of the following reactions CH3NH2(aq) + CH3COOH(aq) --> CH3NH3+(aq) + CH3CO2-(aq) I identified CH3NH2 as the base and CH3COOH as the acid. Is this correct? At first I thought it was the other way around, but after looking at the products...

mayarivers3I

PranaviKolla3G wrote:What is the definition of a Bronsted Acid versus a Lewis acid?

A bronsted acid releases H+ ions, whereas a lewis acid accepts electrons. I think another good way to remember it is that bronsted acids have to be able to release a hydrogen, therefore they are molecules that have an H in them.

mayarivers3I

When we are given the coordination compound and have to write formulas for them, is it safe to assume that the overall compound will be neutral?

mayarivers3I

Quick question... my understanding is that we add -ate to the end of the transition metal when the overall charge of the coordination compound is negative, no matter if the transition metal itself has a positive or negative charge, correct?

mayarivers3I

Yes this is true. A ligand is polydentate if it can occupy more than one binding site, so if a ligand has a free lone pair, then it would be polydentate.

mayarivers3I

I'm pretty sure the oxidation number should always be after the transition metal.

mayarivers3I

The roman numeral is the charge of the metal in the compound.

mayarivers3I

The question is "Which of the following ligands can be polydentate? If the ligand can be polydentate, give the maximum number of places on the ligand that can bind simultaneously to a single metal center"

How do you know if a ligand can be polydentate and how do you answer the second part?

mayarivers3I

What do you look at to determine the oxidation number of the metal in a compound?

mayarivers3I

Are we expected to remember the latin name, or will we be given that information?

mayarivers3I

For the most part you should identify the molecular shape, which would be seesaw. Knowing the geometric shape, like tetrahedral, would be good for predicting the bond angles of the molecule.

mayarivers3I

Why is the bond angle of O2 120 when the shape is linear? Is it because the geometrical shape is trigonal planar?

mayarivers3I

It asks us to draw the lewis structure for the compound HOCO. Why does the answer key have the lewis structure as H-O-C--O with a radical on the carbon and two lone pairs on the oxygens instead of H-O--C--O with one lone pair on the first oxygen and two lone pairs on the second oxygen? (-- means dou...

mayarivers3I

The question is: Draw the Lewis structure and predict whether each of the following molecules is polar or nonpolar. The molecule I am confused about is CH2Cl2 because I put the two hydrogens on opposite sides of the carbon atom and the two chlorines on the other two sides on the carbon, which cancel...

mayarivers3I

The question is-- Predict whether each of the following molecules is likely to be polar or nonpolar: (a)C5H5N; (b)C2H6; (c)CHCl3

What do you look at to determine if a molecule is polar or nonpolar?

mayarivers3I

I think you compare it to the bond angle based that correlates to the shape of the molecule, and determine if the specific bond angle will be greater than or lesser than based on electron repulsion.

mayarivers3I

The first model must have lone pairs because electron repulsion is what's causing the shape to be bent. The second may have lone pairs because the shape of a molecule can be straight if there are a balanced amount of lone pairs.

mayarivers3I

Yes, I believe you just need to be able to determine if an angle is greater or lesser than the expected bond angle.

mayarivers3I

Having a lone pair can be an indicator for polarity, but it's not the sole reason so it's not safe to assume this.

mayarivers3I

The element that should have the negative formal charge is the most electronegative element.

mayarivers3I

It's fine to not have a formal charge of zero. The structure with the lowest energy would be the one where the formal charge is on the most electronegative element.

mayarivers3I

Yes, having the d-block is the reason why elements can have more than 8 electrons in their outer shell.

mayarivers3I

Elements with a d orbital, which are in the third period and beyond, can have an expanded octet.

mayarivers3I

To draw a resonance structure you rearrange the bonds. The resonance structure that's the best is the one with the least formal charge on the most electronegative element.

mayarivers3I

I was told that electrons are removed from the outer most shell, so it would make sense for 4s to be the orbital that the electron is removed from because thats the outer most orbital.

mayarivers3I

I'm still confused as to how the d block works. When do I know to fill the 3d orbital before the 4s orbital? And when that occurs, does the electron configuration always end in 4s^1?

mayarivers3I

To determine the number of orbitals from just the quantum number you would have to look at ml. If you are given that n=2 and l=1 for example, that means we are looking at the d orbital, and because l=1, ml= -1,0,1, so therefore there are three orbitals.

mayarivers3I

Ml is actually the magnetic quantum number, which refers to the orientation of the orbital, so if l=3, then ml would be -3,-2,-1,0,1,2,3. Ms is what refers to the spin, which are the two values 1/2 and -1/2.

mayarivers3I

I think the numbers that are important to know in regards to quantum are that n can be 0,1,2,3..., l can be 0,1,2,3...n-1, and ml can be -l,0,l.

mayarivers3I

The question is asking to write the most likely charge for the ions formed by each of the following elements: (a) S; (b) Te; (c) Rb; (d) Ga. My question how would we determine this? Am I determining which elements are more likely to lose/gain an electron, which would mean figuring out the ionization...

mayarivers3I

I think of a resonance structure as a twin because although they are similar, they are different from each other. Basically, you can tell if a structure is a resonance structure if there are multiple ways to place the bonds because there are several of the same element, for example.

mayarivers3I

Ionization energy is the energy needed to remove an electron. The reason it has the same trend as electronegativity is because as an atom's electrons become more attracted to its nucleus (aka electronegativity increases), the energy needed to remove an electrons would also increase. They both have t...

mayarivers3I

I think the radius of an atom more so affects its electronegativity. The bigger the radius of an atom, the further away the electrons are from the nucleus, so the attraction between the protons and electrons becomes weaker, which decreases electronegativity.

mayarivers3I

Electronegativity is an atom's ability to hold on to their electrons. The way I remember that electronegativity increases across a period is that atoms in the same row have the same number of shells, but the number of valence electrons increases across the row, so the attraction between the protons ...

mayarivers3I

The Einstein equation is used to solve for energy of an electron, but can also be useful to solve for other things such as frequency because that equation is C=(lambda)v.

mayarivers3I

The De Broglie equation is used to calculate the wavelength of a particle when given the mass and velocity, or sometimes momentum is given, which is mass x velocity. Since the equation is used to find the wavelength, then the units are typically meters.

mayarivers3I

Increasing the intensity of light does not eject an electron because in order for that to happen there would need to be an increase in frequency, and increasing the intensity only increases the photons, therefore an electron would not be ejected.

mayarivers3I

The n level is related to the size and energy of the orbitals, which can also be referred to as the principle quantum number. N can be 1,2,3...

mayarivers3I

Wavelength is a measure of distance so the unit is meters, but can be seen as pico- and nano- meters.

mayarivers3I

Which of the following subshells cannot exist in an atom: (a)2d; (b)4d, (c)4g; (d)6f?

What's the trick to figure this out quickly?

mayarivers3I

What equation do I use to find the velocity of a neutron of wavelength 100pm?

mayarivers3I

You have to use Planck's constant, which is 6.626 x 10^-34.

mayarivers3I

Which of the following increase when an electron in a lithium atom undergoes a transition from the 1s-orbital to a 2p-orbital? (a) Energy of the electron. (b) Value of n. (c) Value of l. (d) Radius of the atom. Can someone explain in simple terms which of these answers would be different for hydroge...

mayarivers3I

Sodium vapor lamps emit yellow light of wavelength 589nm. How much energy is emitted by 1.00 mol of sodium atoms emitting light at this wavelength?
How do you go about solving part c of this problem?

mayarivers3I

When using the atomic weight to calculate molar mass, does it matter if we round the atomic weight. For instance, would there be a difference in my answer if I used 15.999 or 16 for oxygen?

mayarivers3I

You can calculate molar mass by using the periodic table. If the molecular formula is given, then all you have to do is plug in the element masses into the formula, multiply by the subscripts, and add all together to get the molar mass.

mayarivers3I

For this question we were asked to determine which pair contains the greater number of moles of atoms, and one pair that was given was 7.36 x 10^27 atoms of Ru and 7.36 X 10^27 atoms of Fe. For clarification, since there are the same amount of atoms, wouldn't the samples given be equivalent in numbe...

mayarivers3I

When I do sig figs for multistep problems, I don't round until the final answer because it's easier to continue the calculations on a calculator and your final answer will be more accurate.

mayarivers3I

If the problem gives you the molar mass of the compound, then you can find the molar mass of the formula that's given and compare that to the given mass, and if it's the same, then that's the molecular formula, otherwise it is the empirical formula.

Search found 52 matches