CHEMISTRY COMMUNITY

mayra martinez 1D

you should memorize so that you can more easily identify them or so that you can more easily identify a weak acid.

mayra martinez 1D

Well attaching more oxygen molecules helps distribute the negative charge of the conjugate base over more atoms and so that makes the proton less strongly attracted to the oxygen atoms in the conjugate base and thus you have a stronger acid.

mayra martinez 1D

Oxygens tend to form more double bonds, both with each other and with other elements and so that makes the molecule more negative and strong.

mayra martinez 1D

The professor stated that the material in the syllabus would be covered in the final and so if the content is stated in the textbook it might be something to remember.

mayra martinez 1D

amines are lewis bases and so they give away electrons since the nitrogen has a lone pair and take in protons making them weak bases.

mayra martinez 1D

Lewis acids have empty orbitals which means that they can accept electrons while lewis bases give away their electrons.

mayra martinez 1D

yea it depends on which is more beneficial in terms of polarity. If you want to have a nonpolar molecule with a zero dipole moment then do trans but if you want a polar molecule with a nonzero dipole moment, then cis.

mayra martinez 1D

yea you don't have to specify the energy level just make sure you know the number of orbitals needed and that you represent it with the correct hybridization in terms of s and p.

mayra martinez 1D

There are also tables you can look at online that can give you a general idea of what to expect the charges of the elements to be. For example, you can look at trends in ionic charge and it shows that for elements in the left side of the periodic table charges will be positive and for the right side...

mayra martinez 1D

Adding on to the roman numeral question, the roman numeral indicates the charge of the transition metal cation and its used in situations where there are multiple oxidation states that the metal can form and so it helps distinguish the state of the metal. You can generally find it by looking at the ...

mayra martinez 1D

Yea to add on, you can write out the molecule in terms of A and x and E to represent the central atom, surrounding atoms and lone pairs, respectively. This allows you to see how many centers of electron density there are and thus be able to write out the corresponding shape and hybridazation.

mayra martinez 1D

Well the process of intermixing one S-orbital and two P-orbitals gives three identical hybrid orbitals known as Sp2 or trigonal hybridization. So hybridization changes the energy levels.

mayra martinez 1D

Adding on to that, sigma bonds are more spherical because they correspond with the s-orbital. The pi bonds are more dumbell shape and they correspond with the p-obitals.

mayra martinez 1D

Yea so to summarize, 3d^5 and 3d^10 have a lower Ionization energy than 4s^2 so we fill those shells first before adding electrons to the s-orbital. But for the rest of the atoms in that period you would first fill the s-orbital and then send electrons to the d-orbital.

mayra martinez 1D

Adding on, we have to draw tetrahedrals in 3D because of the number of bond lengths and so we include the axis x, y,z. When we want to represent a bond in the z axis we draw IIIII lines to represent a bond behind the central atom and we draw a dark triangle to represent a bond to the front of the ce...

mayra martinez 1D

Hey, for this you have to remember that we're drawing the structure in 3D so the dashed lines IIIIII represent a bond behind the central atom and the dark triangle shape represents a bond to the front of the central atom.

mayra martinez 1D

The only reason we write it that way is that you want to go from the lowest quantum number which is 4d^10 to the highest quantum number which is 5s.

mayra martinez 1D

Well in chem 14A when you are doing electron configurations and you are writing down spins in each subshell, subshells with two paired spins are diamagnetic but if even one subshell has one unpaired spin then the whole atom is considered paramagnetic.

mayra martinez 1D

Yea essentially the topic of electron configuration is one that will be prominent in this course and you need to understand how to do that first in order to be able to determine the shape of the orbitals that those configurations compose.

mayra martinez 1D

If you use the equation Ek= hv-work function you can set it up as: work function= hv-Ek and you can just substitute for h, v and Ek. Depending on what you're given just know that you can always switch around the equation to fit to what you need and that you can use other equations to help you solve ...

mayra martinez 1D

Yea so to reiterate, as the n increases, the energies of successive levels increase (thus become less negative) until you approach zero, where the electron is on the point of escaping the atom. All the energies are negative because the electron has a lower energy in the atom, than when its far from ...

mayra martinez 1D

Well the reason the equation En= -hR/n^2 only works for the hydrogen atom is because for hydrogen z=1. For other one-electron ions (ex: He^+ or C^5+) with an atomic number z=# we use the equation En= (-z^2)HR/n^2. This is because the greater the value of the nuclear charge, the more tightly bound th...

mayra martinez 1D

For cations you know you will be removing electrons and so based on the ion's charge that's how many electrons you remove, thus giving you a positive ion.

mayra martinez 1D

Yeah, the close to the nucleus,the harder to steal and so the electrons from subshells further away will be the ones to go first due to less resistance.

mayra martinez 1D

The term radical can refer to an electron that remains after a compound has been formed. This free electron is looking to bond to another electron in order to become stable.

mayra martinez 1D

Also note that the amount of energy a photon carries is directly proportional to the photon's electromagnetic frequency (f) and it's also inversely proportional to the wavelength(λ). So the higher the frequency, the higher its energy and the longer the wavelength, the lower its energy( and vise vers...

mayra martinez 1D

A regular atomic radius is the distance between the nucleus and the last electron cloud. A covalent radius is half the distance between the nuclei of the newly-bonded atoms. The diameter would be the full distance between the two nuclei. An ionic radius is similar to the atomic radius; its the dista...

mayra martinez 1D

Electron affinity is the energy released when an electron is added to a neutral atom in order to form a negative ion. Electron affinity increases as you go up the periodic table and from left to right to the periodic table. This is because the electrons added to the energy levels get closer to the n...

mayra martinez 1D

In the solutions manual they recommend using 2.998x10^8 m/s for the speed of light but if you round up then yea you could use 3x10^8

mayra martinez 1D

If I recall correctly, the professor in lecture stated that he does expect us to write out the states of matter for the reactants and products in chemical equations. And in simple terms, when a molecule is defined as aqueous it means that it has been dissolved in water.

mayra martinez 1D

The mass of products can't be greater than the mass of reactants that's why the second step in solving a stoichiometry problem is writing a balanced equation for the reaction. This is due to the law of conservation of matter.

mayra martinez 1D

For significant figures, you have to remember that your result can't have more significant figures than the least precise number in the problem.

CHEMISTRY COMMUNITY

Search found 32 matches

Re: Memorizing Acids by name

Re: Oxyacids

Re: Oxygen atoms in acid structures?

Re: Acid Rain on the Final

Re: Amines and strength of acid

Re: Acid vs base [ENDORSED]

Re: Cis and Trans

Re: 2s or s?

Re: Charges

Re: Naming Coordination Compounds

Re: sp3 hybridization

Re: Energy Level

Re: Sigma and Pi Bonds [ENDORSED]

Re: the ground state and ion exceptions

Re: Tetrahedral Shape Question

Re: Symbol meanings between chemical bonds

Re: Question 2.43

Re: Paramagnetism

Re: Molecular Shape

Re: Work Function

Re: Why is there a negative?

Re: H spectrum

Re: Electron Configuration of Cations

Re: Electron Configuratin

Re: Radicals

Re: Photon energy

Re: Types of Radii

Re: electron affinity [ENDORSED]

Re: speed of light

Re: Defining compounds in equations

Re: Mass of products/Reactants [ENDORSED]

Re: Significant figures in textbook 7th edition [ENDORSED]