Search found 32 matches
- Sun Dec 09, 2018 12:01 am
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Memorizing Acids by name
- Replies: 3
- Views: 702
Re: Memorizing Acids by name
you should memorize so that you can more easily identify them or so that you can more easily identify a weak acid.
- Sat Dec 08, 2018 11:59 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Oxyacids
- Replies: 4
- Views: 1018
Re: Oxyacids
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.
- Sat Dec 08, 2018 11:57 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Oxygen atoms in acid structures?
- Replies: 3
- Views: 654
Re: Oxygen atoms in acid structures?
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.
- Fri Nov 30, 2018 5:50 pm
- Forum: Air Pollution & Acid Rain
- Topic: Acid Rain on the Final
- Replies: 4
- Views: 704
Re: Acid Rain on the Final
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.
- Fri Nov 30, 2018 5:48 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Amines and strength of acid
- Replies: 4
- Views: 398
Re: Amines and strength of acid
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.
- Fri Nov 30, 2018 5:46 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Acid vs base [ENDORSED]
- Replies: 15
- Views: 1407
Re: Acid vs base [ENDORSED]
Lewis acids have empty orbitals which means that they can accept electrons while lewis bases give away their electrons.
- Fri Nov 30, 2018 5:43 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Cis and Trans
- Replies: 10
- Views: 922
Re: Cis and Trans
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.
- Fri Nov 30, 2018 5:39 pm
- Forum: Hybridization
- Topic: 2s or s?
- Replies: 7
- Views: 612
Re: 2s or s?
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.
- Fri Nov 30, 2018 5:34 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Charges
- Replies: 4
- Views: 496
Re: Charges
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...
- Fri Nov 30, 2018 5:28 pm
- Forum: Naming
- Topic: Naming Coordination Compounds
- Replies: 9
- Views: 1022
Re: Naming Coordination Compounds
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 ...
- Sun Nov 18, 2018 5:48 pm
- Forum: Hybridization
- Topic: sp3 hybridization
- Replies: 6
- Views: 464
Re: sp3 hybridization
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.
- Sun Nov 18, 2018 5:44 pm
- Forum: Hybridization
- Topic: Energy Level
- Replies: 2
- Views: 312
Re: Energy Level
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.
- Sun Nov 18, 2018 5:36 pm
- Forum: Hybridization
- Topic: Sigma and Pi Bonds [ENDORSED]
- Replies: 12
- Views: 1011
Re: Sigma and Pi Bonds [ENDORSED]
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.
- Fri Nov 09, 2018 5:37 pm
- Forum: Hybridization
- Topic: the ground state and ion exceptions
- Replies: 2
- Views: 281
Re: the ground state and ion exceptions
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.
- Fri Nov 09, 2018 5:31 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Tetrahedral Shape Question
- Replies: 3
- Views: 343
Re: Tetrahedral Shape Question
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...
- Fri Nov 09, 2018 5:20 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Symbol meanings between chemical bonds
- Replies: 2
- Views: 282
Re: Symbol meanings between chemical bonds
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.
- Sun Nov 04, 2018 3:05 pm
- Forum: Hybridization
- Topic: Question 2.43
- Replies: 4
- Views: 479
Re: Question 2.43
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.
- Sun Nov 04, 2018 3:02 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Paramagnetism
- Replies: 3
- Views: 667
Re: Paramagnetism
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.
- Sun Nov 04, 2018 2:53 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Molecular Shape
- Replies: 2
- Views: 436
Re: Molecular Shape
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.
- Thu Oct 25, 2018 11:34 pm
- Forum: Photoelectric Effect
- Topic: Work Function
- Replies: 14
- Views: 2134
Re: Work Function
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 ...
- Thu Oct 25, 2018 11:20 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Why is there a negative?
- Replies: 4
- Views: 465
Re: Why is there a negative?
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 ...
- Thu Oct 25, 2018 11:10 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: H spectrum
- Replies: 3
- Views: 406
Re: H spectrum
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...
- Fri Oct 19, 2018 5:19 pm
- Forum: Ionic & Covalent Bonds
- Topic: Electron Configuration of Cations
- Replies: 8
- Views: 819
Re: Electron Configuration of Cations
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.
- Fri Oct 19, 2018 5:12 pm
- Forum: Ionic & Covalent Bonds
- Topic: Electron Configuratin
- Replies: 5
- Views: 395
Re: Electron Configuratin
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.
- Fri Oct 19, 2018 5:09 pm
- Forum: Lewis Structures
- Topic: Radicals
- Replies: 2
- Views: 255
Re: Radicals
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.
- Thu Oct 11, 2018 10:57 pm
- Forum: Properties of Light
- Topic: Photon energy
- Replies: 3
- Views: 299
Re: Photon energy
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...
- Thu Oct 11, 2018 10:47 pm
- Forum: Trends in The Periodic Table
- Topic: Types of Radii
- Replies: 2
- Views: 492
Re: Types of Radii
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...
- Thu Oct 11, 2018 10:25 pm
- Forum: Trends in The Periodic Table
- Topic: electron affinity [ENDORSED]
- Replies: 15
- Views: 1857
Re: electron affinity [ENDORSED]
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...
- Thu Oct 11, 2018 10:05 pm
- Forum: Properties of Light
- Topic: speed of light
- Replies: 8
- Views: 640
Re: speed of light
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
- Thu Oct 04, 2018 6:39 pm
- Forum: Limiting Reactant Calculations
- Topic: Defining compounds in equations
- Replies: 3
- Views: 210
Re: Defining compounds in equations
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.
- Thu Oct 04, 2018 6:29 pm
- Forum: Limiting Reactant Calculations
- Topic: Mass of products/Reactants [ENDORSED]
- Replies: 3
- Views: 213
Re: Mass of products/Reactants [ENDORSED]
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.
- Thu Oct 04, 2018 6:15 pm
- Forum: Limiting Reactant Calculations
- Topic: Significant figures in textbook 7th edition [ENDORSED]
- Replies: 5
- Views: 336
Re: Significant figures in textbook 7th edition [ENDORSED]
For significant figures, you have to remember that your result can't have more significant figures than the least precise number in the problem.