Search found 50 matches
- Mon Dec 02, 2019 1:35 pm
- Forum: Identifying Acidic & Basic Salts
- Topic: Relative Acidity
- Replies: 2
- Views: 217
Re: Relative Acidity
Because strong acids have weaker bonds. Weak bonds usually indicate greater instability since they can easily be broken which explains why the stronger the acid the greater the dissociation of the acid in water to make the acid more stable by losing the hydrogen bond to form an anion.
- Mon Dec 02, 2019 1:31 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: pH of acids
- Replies: 13
- Views: 3596
Re: pH of acids
A substance becomes more acidic as the pH decreases therefore the lower the pH the stronger the acid. The higher the pH the more basic the substance is therefore a substance with a higher pH will have be a weaker acid.
- Mon Dec 02, 2019 1:27 pm
- Forum: Amphoteric Compounds
- Topic: amphiprotic and amphoteric
- Replies: 9
- Views: 748
Re: amphiprotic and amphoteric
If an atom is said to be amphiprotic then that means that the atom has the ability to donate or accept protons whereas amphoteric is the ability of an atom to act as an acid or base.
- Mon Dec 02, 2019 1:24 pm
- Forum: Conjugate Acids & Bases
- Topic: Ligands
- Replies: 12
- Views: 672
Re: Ligands
A ligand is an ion or molecule that binds to a central atom to form a coordination compound by donating a pair of electrons to the acid.
- Mon Dec 02, 2019 1:22 pm
- Forum: Conjugate Acids & Bases
- Topic: Definition
- Replies: 7
- Views: 497
Re: Definition
Conjugate acid = A chemical compound formed by the reception of a proton by a base. It is a base with a hydrogen ion added to it.
Conjugate base = The species that is formed when an acid dissociates into its ions in water, it loses a hydrogen ion.
Conjugate base = The species that is formed when an acid dissociates into its ions in water, it loses a hydrogen ion.
- Mon Nov 25, 2019 1:25 pm
- Forum: Biological Examples
- Topic: Cisplatin [ENDORSED]
- Replies: 19
- Views: 1336
Re: Cisplatin [ENDORSED]
It is a type of chemotherapy which stops cell division in an attempt to keep the cancerous cells from spreading. Unfortunately it also affects normal healthy cells' ability to multiply.
- Mon Nov 25, 2019 1:23 pm
- Forum: Naming
- Topic: Di-, Tri-, Tetra- vs Bis-, Tris-, Tetrakis-
- Replies: 11
- Views: 984
Re: Di-, Tri-, Tetra- vs Bis-, Tris-, Tetrakis-
You would use them if the ligand already had a prefix of di-, tr-, etc.
- Mon Nov 25, 2019 1:22 pm
- Forum: Hybridization
- Topic: Hybridization number
- Replies: 3
- Views: 287
Re: Hybridization number
Yes because atom hybridization can be determined based on electron density surrounded the central atom (lone pairs and bonds attached to central atom). You find the hybridization number by simply counting the number lone pair regions and bonded pairs attached to the central atom.
- Mon Nov 25, 2019 1:19 pm
- Forum: Hybridization
- Topic: When does hybridization occur?
- Replies: 7
- Views: 460
Re: When does hybridization occur?
Hybridization occurs when an atom needs to form more bonds than it would normally form in its ground state
- Mon Nov 25, 2019 1:16 pm
- Forum: Hybridization
- Topic: sigma or pi?
- Replies: 20
- Views: 1178
Re: sigma or pi?
Since sigma bonds always form first if there is a single bond then it is a sigma bond, if there is a double bond then there is one single bond and one pi bond present, and if there is a triple bond then there is still only 1 sigma bond but 2 pi bonds.
- Mon Nov 18, 2019 12:12 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: AXE notation
- Replies: 10
- Views: 685
Re: AXE notation
The AXE notation helps you determine molecular shape but it is important to note that just because molecules have the same formula have the same general shape but their bond angles may differ slightly
- Mon Nov 18, 2019 12:09 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shape
- Replies: 3
- Views: 257
Re: Molecular Shape
Yes that's right. Electron density affects molecular shape but you only refer to the electron which directly surround the atom itself
- Mon Nov 18, 2019 12:08 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR notation
- Replies: 6
- Views: 428
Re: VSEPR notation
That's right
- Mon Nov 18, 2019 12:07 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR, Molecular Geometry, and Molecular Shape
- Replies: 4
- Views: 370
Re: VSEPR, Molecular Geometry, and Molecular Shape
There is no difference. A VSEPR Model is just a way to show molecular geometry and shape
- Mon Nov 18, 2019 12:02 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Why is SF4 Polar?
- Replies: 6
- Views: 829
Re: Why is SF4 Polar?
Since there is a seesaw shape the shape of the molecule is not symmetrical so the energies don't cancel making it polar
- Mon Nov 11, 2019 3:48 pm
- Forum: Dipole Moments
- Topic: Van Der Waals Interaction
- Replies: 2
- Views: 219
Van Der Waals Interaction
What is a Van Der Waals interaction and how is it different from a dipole moment? Or is it the same thing?
- Mon Nov 11, 2019 3:46 pm
- Forum: Bond Lengths & Energies
- Topic: Shorter bond lengths
- Replies: 12
- Views: 710
Re: Shorter bond lengths
More bonds lead to shorter bond lengths because shorter bonds are stronger because the force of attraction with more electrons involved is stronger.
- Mon Nov 11, 2019 3:43 pm
- Forum: Dipole Moments
- Topic: Dipole Moment
- Replies: 6
- Views: 344
Re: Dipole Moment
You know there is a dipole moment when there is an unequal sharing of electrons among atoms. The arrow always points in the direction in which the electron os being pulled.
- Mon Nov 11, 2019 3:40 pm
- Forum: Dipole Moments
- Topic: Dissociation Energies
- Replies: 3
- Views: 158
Re: Dissociation Energies
Dissociation energies are always positive because it always requires energy to break a bond
- Mon Nov 11, 2019 3:39 pm
- Forum: Dipole Moments
- Topic: Dipole Moments
- Replies: 6
- Views: 374
Re: Dipole Moments
A dipole moment is when a molecule has a positive charge next to an equal but opposite negative charge.
- Mon Nov 04, 2019 11:42 am
- Forum: Electronegativity
- Topic: Difference
- Replies: 5
- Views: 319
Re: Difference
Electronegativity is how tightly the electrons are held together and polarizability is how easy/difficult it is to lose an electron.
- Mon Nov 04, 2019 11:40 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: formal charge
- Replies: 5
- Views: 367
Re: formal charge
You need to solve for formal charge if the question is asking for the electron configuration with the lowest energy. I thought in class today Lavelle said that he wanted us to always show the configuration with the lowest energy so I would just solve accordingly every time.
- Mon Nov 04, 2019 11:37 am
- Forum: Ionic & Covalent Bonds
- Topic: Electron Configuration
- Replies: 7
- Views: 434
Re: Electron Configuration
Yes because you always want to show the most stable structure and half filled shells are more stable.
- Mon Nov 04, 2019 11:34 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: HW Question 1A.15
- Replies: 1
- Views: 182
HW Question 1A.15
Whenever I solve this equation out am getting the the energy of the photon is 1.936x10^-18 J but there is apparently this whole answer is supposed to be negative. Could someone please explain why this is; where does the negative sign come from?
- Mon Nov 04, 2019 11:31 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: N initial and N final
- Replies: 1
- Views: 1179
N initial and N final
When trying to find energy level n initial or n final I know you use the equation delta E=(-hR/nf^2)-(-hR/ni^2) but when ever I try to isolate out the variable I am looking for I am off by 1 negative sign every time and I don't know what I am doing wrong. Could someone please show the work for this ...
- Mon Oct 28, 2019 2:34 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ground State
- Replies: 11
- Views: 557
Re: Ground State
The ground state energy of an atom is when the atom is in it lowest energy state in which orbital subshells are paired before the electrons can move up to a higher orbital.
- Mon Oct 28, 2019 2:28 pm
- Forum: Sigma & Pi Bonds
- Topic: Single vs. Double bonds
- Replies: 15
- Views: 1957
Re: Single vs. Double bonds
Double bonds are stronger and pull the atoms closer together which makes them shorter
- Mon Oct 28, 2019 2:26 pm
- Forum: Octet Exceptions
- Topic: expanded octet?
- Replies: 9
- Views: 472
Re: expanded octet?
Elements that haven't filled their d-orbital can have an expanded octet.
- Mon Oct 28, 2019 2:24 pm
- Forum: Resonance Structures
- Topic: Resonance vs. Resonance Hybrid
- Replies: 2
- Views: 141
Resonance vs. Resonance Hybrid
Is there a difference between resonance and resonance hybrid structures and if so what is it because I have been getting confused as to when I need to put the double headed arrow between the different molecules.
- Mon Oct 28, 2019 2:19 pm
- Forum: Electronegativity
- Topic: Calculating Electronegativity
- Replies: 3
- Views: 135
Calculating Electronegativity
How do you calculate electronegativity?
- Mon Oct 21, 2019 12:16 pm
- Forum: Trends in The Periodic Table
- Topic: 1st and 2nd Ionization
- Replies: 5
- Views: 279
1st and 2nd Ionization
What is the difference between 1st ionization energy and second ionization energy?
- Mon Oct 21, 2019 12:14 pm
- Forum: Trends in The Periodic Table
- Topic: Isoelectronic Atoms
- Replies: 6
- Views: 449
Isoelectronic Atoms
When explaining isoelectronic atoms in class today he kept mentioning the electrons in terms of OF electrons. What are OF electrons?
- Mon Oct 21, 2019 12:09 pm
- Forum: Trends in The Periodic Table
- Topic: Ionization Energy
- Replies: 8
- Views: 328
Re: Ionization Energy
Electrons repel each other so the more electrons you have the greater the repulsion you have from the nuclear. By that logic, if you start to remove electrons the attractive forces between the surrounding electrons and the nucleus increases because there are less forces which repel the electrons. Th...
- Mon Oct 21, 2019 12:03 pm
- Forum: Trends in The Periodic Table
- Topic: Atomic Radius
- Replies: 7
- Views: 484
Re: Atomic Radius
Atomic radius is the is half the distance between the centers of 2 neighboring atoms. Atomic radius decreases as you go across the periodic table from left to right and increases as you go down the periodic table.
- Mon Oct 21, 2019 12:01 pm
- Forum: Trends in The Periodic Table
- Topic: Difference between electron affinity and electronegativity?
- Replies: 3
- Views: 146
Re: Difference between electron affinity and electronegativity?
Electron affinity is the amount of energy released when electrons are added to a gas phase atom and electronegativity is the tendency of an atom to attract a shared pair of electrons towards itself.
- Mon Oct 14, 2019 8:37 pm
- Forum: Einstein Equation
- Topic: E=hv [ENDORSED]
- Replies: 52
- Views: 18446
Re: E=hv [ENDORSED]
E is supposed to represent the energy of a photon
- Mon Oct 14, 2019 8:36 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron configuration order
- Replies: 4
- Views: 265
Re: Electron configuration order
I think it just cuts out the middle ground and jumps to the next orbital so you are supposed to assume that the previous orbital is filled in order for the element to be in that position.
- Mon Oct 14, 2019 8:30 pm
- Forum: Trends in The Periodic Table
- Topic: Atomic Radius
- Replies: 16
- Views: 955
Re: Atomic Radius
The radius isn't measured in the excited state. It's only measured in the ground state.
- Mon Oct 14, 2019 8:29 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Radii
- Replies: 2
- Views: 104
Radii
What is the difference between ionic and atomic radius?
- Mon Oct 14, 2019 8:26 pm
- Forum: Ionic & Covalent Bonds
- Topic: Bonds
- Replies: 4
- Views: 424
Bonds
What type of atoms prefer ionic bonds and what type of atoms prefer covalent bonds?
- Tue Oct 08, 2019 11:40 pm
- Forum: Balancing Chemical Reactions
- Topic: Subscripts [ENDORSED]
- Replies: 3
- Views: 217
Subscripts [ENDORSED]
When balancing chemical equations you can only add/change the coefficient right? You can't change the subscript number? Because I've noticed a few differences in the solutions manual from the textbook and I don't know if there is just a misprint in 1 of the 2 books or if there is a rule that I am un...
- Tue Oct 08, 2019 11:35 pm
- Forum: Empirical & Molecular Formulas
- Topic: empirical to molecular formula [ENDORSED]
- Replies: 9
- Views: 613
Re: empirical to molecular formula [ENDORSED]
You divide the given molar mass (the mass of the molecular formula) by the molar mass of the empirical formula. Whatever the product of that equation is is the number you multiply the empirical formula by.
- Tue Oct 08, 2019 11:29 pm
- Forum: Empirical & Molecular Formulas
- Topic: Formula Units
- Replies: 10
- Views: 406
Re: Formula Units
Formula units can be an atom, compound, or a molecule. So basically you just have to use Avogadro's number to solve the equation.
- Tue Oct 08, 2019 11:25 pm
- Forum: SI Units, Unit Conversions
- Topic: Problem G.23
- Replies: 3
- Views: 236
Problem G.23
For problem G.23 in the homework do you have to add the moles together of Cl in order to calculate the molarity of the element?
- Tue Oct 08, 2019 11:17 pm
- Forum: Trends in The Periodic Table
- Topic: Chemistry Community
- Replies: 4
- Views: 195
Chemistry Community
Since we have to post on chemistry community 5 times a week for credit does that mean that it's due before discussion each week or by Friday?
- Tue Oct 08, 2019 11:16 pm
- Forum: Trends in The Periodic Table
- Topic: Chemistry Community
- Replies: 8
- Views: 497
Chemistry Community
Since we have to post on chemistry community 5 times a week for credit does that mean that it's due before discussion each week or by Friday?
- Thu Oct 03, 2019 8:10 pm
- Forum: Balancing Chemical Reactions
- Topic: Net Ionic Units
- Replies: 2
- Views: 140
Net Ionic Units
When finding the net ionic units do polyatomic ions remain connected or do you multiply out the end subscript by the preceding number?
- Thu Oct 03, 2019 9:15 am
- Forum: Empirical & Molecular Formulas
- Topic: Test Materials
- Replies: 13
- Views: 738
Test Materials
Does anyone know if we will be given a periodic table for the tests in 14A?
- Thu Oct 03, 2019 9:12 am
- Forum: Significant Figures
- Topic: Significant Figures
- Replies: 10
- Views: 807
Significant Figures
What are the rules for significant figures again? It's been a while since I've done this and I cannot remember how to determine the correct number of significant figures for a problem/how it would be written.
- Thu Oct 03, 2019 9:10 am
- Forum: SI Units, Unit Conversions
- Topic: Finding Molar Mass
- Replies: 3
- Views: 151
Finding Molar Mass
In an equations such as Part D of question E. 23 where the the molecular equation is shown as Na(subscript)2 CO(subscript) 3 dot 10H(subscript)2O do add or multiplayer;y to the 2 equations to find the total molecular mass because I have tried both ways and seem to be getting a different answer from ...