Search found 50 matches
- Sat Nov 30, 2019 8:40 pm
- Forum: Lewis Acids & Bases
- Topic: Nitrate
- Replies: 4
- Views: 258
Re: Nitrate
There is a chart in 9C that lists common compounds, I think we are supposed to learn those.
- Sat Nov 30, 2019 8:39 pm
- Forum: Bond Lengths & Energies
- Topic: Melting Points
- Replies: 8
- Views: 767
Re: Melting Points
Yes, a stronger IMF relates to a higher melting/boiling point and a lower vapor pressure.
Re: Conjugate
A conjugate acid can donate a proton, and a conjugate base is the species that remains after the acid has donated its proton.
- Sat Nov 30, 2019 8:36 pm
- Forum: Amphoteric Compounds
- Topic: compounds
- Replies: 5
- Views: 364
Re: compounds
The compound can be both acidic or basic, by donating a proton or accepting a proton.
- Sat Nov 30, 2019 8:19 pm
- Forum: Bronsted Acids & Bases
- Topic: HBr
- Replies: 3
- Views: 247
Re: HBr
That seems correct to me because the HBr has a H that is can give up to the water, which would act as a base. Br wouldn't be able to fit another proton either.
- Sat Nov 30, 2019 8:17 pm
- Forum: Amphoteric Compounds
- Topic: 6A. 11
- Replies: 3
- Views: 270
Re: 6A. 11
These compounds can act as both acids and bases. One reaction will produce H30+, while the other will produce OH-
- Sun Nov 24, 2019 10:21 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Heisenberg Equation
- Replies: 4
- Views: 540
Re: Heisenberg Equation
You cannot know simultaneously the position and momentum of a particle. The most uncertainty you have in the position of the particle, the less there can be in the momentum and vice versa.
- Sun Nov 24, 2019 10:19 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond angles
- Replies: 7
- Views: 453
Re: Bond angles
Yes, the bond angles are approximately 90, 120, and 180 degrees.
- Sun Nov 24, 2019 10:18 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Drawing Structures
- Replies: 4
- Views: 286
Re: Drawing Structures
As people said, drawing a standard lewis structure is all we have to do I think.
- Sun Nov 24, 2019 10:17 pm
- Forum: Naming
- Topic: Trans and Cis
- Replies: 8
- Views: 506
Re: Trans and Cis
From what I understand, trans and cis are just 2 versions of resonance structures. Trans and typically non polar, while cis are polar.
- Sun Nov 24, 2019 10:16 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: AXE Format
- Replies: 34
- Views: 1260
Re: AXE Format
The subscript isn't needed as it is just assumed there is only one.
- Sun Nov 24, 2019 10:15 pm
- Forum: Sigma & Pi Bonds
- Topic: Molecular Shape
- Replies: 11
- Views: 732
Re: Molecular Shape
The only difference is that sigma bonds allow for rotation, while pi bonds don't. However, with molecular shape, double and single bonds are treated as the same, so it doesn't affect bond shape.
- Sun Nov 17, 2019 7:57 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: types of bonds
- Replies: 14
- Views: 1234
Re: types of bonds
Yes, all single bonds are sigma bonds and the subsequent bonds are pi bonds.
- Sun Nov 17, 2019 7:56 pm
- Forum: Bond Lengths & Energies
- Topic: Bond Length
- Replies: 22
- Views: 1294
Re: Bond Length
As mentioned, it is determined experimentally. We just need to know that double bonds are stronger and shorter than single bonds.
- Sun Nov 17, 2019 7:55 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: dipole moments
- Replies: 7
- Views: 435
Re: dipole moments
Yes, because when two atoms have different electronegativities, one atom will attract the shared electrons more than the other creating a dipole moment and polarity.
- Sun Nov 17, 2019 7:54 pm
- Forum: Electronegativity
- Topic: Noble Gases
- Replies: 40
- Views: 12807
Re: Noble Gases
Noble gases have very small electronegativites since they already have full octets.
- Sun Nov 17, 2019 7:53 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Test 2
- Replies: 19
- Views: 890
Re: Test 2
The double/single bonds doesn't matter as much, the lewis structure just helps you figure out where the lone pairs are and how the bound atoms are distributed.
- Sun Nov 17, 2019 7:51 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Determining a VSEPR model
- Replies: 6
- Views: 405
Re: Determining a VSEPR model
With the VSEPR model, you treat single bonds and double bonds as the same. Thus, it doesn't matter which resonance structure you use.
- Wed Nov 06, 2019 10:30 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Solving with velocity
- Replies: 3
- Views: 325
Re: Solving with velocity
The actual velocity is important for most of the problems we've been solving, and it is usually provided. For energy, the difference in energy is usually what matters more because energy is conserved.
- Wed Nov 06, 2019 10:22 pm
- Forum: Electronegativity
- Topic: Ionic or covalent?
- Replies: 17
- Views: 829
Re: Ionic or covalent?
A bond is ionic typically if the difference between 2 element's electronegativity is greater than 2, and a bond is covalent if the difference in electronegativity is less than 1.5. Many bonds however are partially ionic although they're still considered covalent. These bonds have dipole moments and ...
- Wed Nov 06, 2019 10:20 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Quantum numbers
- Replies: 12
- Views: 777
Re: Quantum numbers
As mentioned, the angular momentum quantum number is determined by l. L can be any value (n-1) and relates to whether an element is in the s, p, d, or f block on the periodic table.
- Wed Nov 06, 2019 10:19 pm
- Forum: Electronegativity
- Topic: Electron affinity
- Replies: 4
- Views: 286
Re: Electron affinity
Electron affinity is how happy an atom is when it receives an electron from another atom. The more positive its electron affinity is, the more energy it will be release when it receives an electron.
- Wed Nov 06, 2019 10:18 pm
- Forum: Dipole Moments
- Topic: Dipole Moments Determined by Electronegativity?
- Replies: 3
- Views: 226
Re: Dipole Moments Determined by Electronegativity?
Dipole moments point toward the more electronegative atom, because their higher electronegativity attracts the other atom's electrons closer toward it. This means that their bond isn't completely covalent. When atoms have a higher difference in electronegativity, the dipole moment is stronger and th...
- Sat Nov 02, 2019 11:55 am
- Forum: Quantum Numbers and The H-Atom
- Topic: determining the number of orbitals
- Replies: 7
- Views: 330
Re: determining the number of orbitals
The number of orbitals correlates to the m quantum number and how man there are. l=0 (s, 0) has 1 orbital, l=1 (p, -1,0,1) has 3 orbitals, l=2 (d, -2,-1,0,1,2) has 5 orbitals, and l=3 (f, -3,-2,-1,0,1,2,3) has 7 orbitals.
- Sat Nov 02, 2019 11:53 am
- Forum: Octet Exceptions
- Topic: Expanded Octet
- Replies: 3
- Views: 184
Re: Expanded Octet
From my understanding, any elements past phosphorus can ave expanded octets due to the having d orbitals that will hold additional eletrons.
- Sat Nov 02, 2019 11:52 am
- Forum: Octet Exceptions
- Topic: More than 8 valence e-
- Replies: 8
- Views: 419
Re: More than 8 valence e-
Once you get past phosphorus, those elements have the d orbitдal in addition to the s and p orbitals, allowing the elements to old additional electrons in their shell
- Sat Nov 02, 2019 11:46 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Understanding Ionic Radius
- Replies: 3
- Views: 280
Re: Understanding Ionic Radius
ionic radius decreases toward the right since the electrons are pulled in loser, but then increase down since the energy level of the elements increases that direction
- Sat Nov 02, 2019 11:45 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Cu and Cr
- Replies: 11
- Views: 582
Re: Cu and Cr
Yes this trend apples to all 4 of the "coinage" metals
- Sat Oct 26, 2019 3:18 pm
- Forum: Octet Exceptions
- Topic: Max number of valence e
- Replies: 6
- Views: 657
Re: Max number of valence e
I think the max number any electron can have is 8 because valence electrons are electrons in the outermost shell of an atom, and there can only be a max of 8 in any shell after the first (which is only 2).
- Sat Oct 26, 2019 3:17 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Quantum number m
- Replies: 3
- Views: 213
Re: Quantum number m
The quantum number m refers to the magnetism of an electron, and for m,s it refers to its spin. An electrons can either be +1/2 or -1/2, meaning it spins up or down. Paired electrons always have opposite spins.
- Sat Oct 26, 2019 3:10 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Noble Gas Configuration
- Replies: 2
- Views: 242
Re: Noble Gas Configuration
In my discussion section, we also went over the full configurations so I would also try to know how to do those. Because for some elements like Cr and Cu there are exceptions as to how they're written.
- Sat Oct 26, 2019 3:09 pm
- Forum: Ionic & Covalent Bonds
- Topic: Atomic Radius
- Replies: 4
- Views: 409
Re: Atomic Radius
Atomic radius directly depends on how many electrons an element has because the more electrons an atom has, the larger it will be. Therefore it increases from left to right and from top to bottom along the periodic table.
- Sat Oct 26, 2019 3:08 pm
- Forum: Properties of Light
- Topic: frequency/intensity
- Replies: 2
- Views: 152
Re: frequency/intensity
I don't think so, intensity has to do with the number of photons being emitted, while frequency refers to the wavelengths per second. Intensity also relates to the amplitude of the radiation's wave function.
- Fri Oct 18, 2019 11:21 pm
- Forum: Properties of Electrons
- Topic: Equations for Test
- Replies: 9
- Views: 373
Re: Equations for Test
Similar to the first test we had, I assume there will be a formula sheet. But understanding the equations and what they mean is probably helpful.
- Fri Oct 18, 2019 11:20 pm
- Forum: Properties of Light
- Topic: Unit for Wavelength
- Replies: 34
- Views: 2504
Re: Unit for Wavelength
In problems, nm are often used because wavelengths are so small. However, make sure that you're using meters for the calculations because that is the SI unit used.
- Fri Oct 18, 2019 11:19 pm
- Forum: Properties of Electrons
- Topic: Momentum
- Replies: 11
- Views: 317
Re: Momentum
Momentum also takes into account mass of an object, and defines how much force or energy it takes to move or stop an object. The heavier the object is, the more momentum it has.
- Fri Oct 18, 2019 11:17 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Heisenberg
- Replies: 4
- Views: 225
Re: Heisenberg
The idea that there are limits to how certain you can't be about a particle's position and velocity at the same time. The more accurate your position measurement is, the less sure you become about velocity and vice versa.
- Fri Oct 18, 2019 11:16 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Coulombs's Law
- Replies: 2
- Views: 150
Re: Coulombs's Law
For this class, I a, pretty sure that r refers to the distance between charges, not their atomic radii since they are so similar in most cases
- Thu Oct 10, 2019 3:55 pm
- Forum: Limiting Reactant Calculations
- Topic: general questions
- Replies: 11
- Views: 1036
Re: general questions
Finding the limiting reactant tells you what the maximum theoretical yield will be because you can only produce as much product as you have reactants to form that product. The limiting reactant is the reagent that is completely used up in the reaction, so it will indicate how much total product can ...
- Thu Oct 10, 2019 3:54 pm
- Forum: Empirical & Molecular Formulas
- Topic: F.21
- Replies: 2
- Views: 145
Re: F.21
I always just follow what the question asks for in terms of units, but during my calculations I try to keep it consistent. You can always convert to grams and liters then convert back for the final answer.
- Thu Oct 10, 2019 3:53 pm
- Forum: Properties of Light
- Topic: Energy of light
- Replies: 4
- Views: 194
Re: Energy of light
Shorter wavelengths correlate to higher frequency, which tells you there is higher energy. Think of something moving super fast, it will have a higher frequency with waves that "move" faster- this correlates with higher energy.
- Thu Oct 10, 2019 3:52 pm
- Forum: Empirical & Molecular Formulas
- Topic: Converting from grams to percentage
- Replies: 11
- Views: 7681
Re: Converting from grams to percentage
Assuming you have a 100g sample is the easiest way to do it because you bypass finding mass percentage composition and equate the given percentages to mass. You then use those masses to find moles.
- Thu Oct 10, 2019 3:51 pm
- Forum: Significant Figures
- Topic: Sig Figs only for Decimal Points vs for all integers in the Answer
- Replies: 5
- Views: 354
Re: Sig Figs only for Decimal Points vs for all integers in the Answer
As Michelle said, I always use the same amount of sig figs in my answer as was given in the original problem and keep more sig figs throughout my calculations to get the most accurate final answer. For multiplication and division, use the lowest amount of sig figs given, and same for addition and su...
- Thu Oct 10, 2019 3:49 pm
- Forum: Einstein Equation
- Topic: E=hv [ENDORSED]
- Replies: 52
- Views: 18454
Re: E=hv [ENDORSED]
E represents the energy of a photon, and change in E can be used to find the difference in energy levels
- Thu Oct 03, 2019 5:29 pm
- Forum: Limiting Reactant Calculations
- Topic: Basic Question
- Replies: 11
- Views: 570
Re: Basic Question
For there to be 2 limiting reactants, I think there would need to be equal amounts of them, which doesn't usually happen.
- Thu Oct 03, 2019 5:28 pm
- Forum: Limiting Reactant Calculations
- Topic: Percentage Yields
- Replies: 8
- Views: 589
Re: Percentage Yields
A high yield means that the actual yield of products is close to the theoretical yield because percent yield equals actual yield divided by theoretical yield.
- Thu Oct 03, 2019 5:26 pm
- Forum: General Science Questions
- Topic: Naming compounds
- Replies: 6
- Views: 297
Re: Naming compounds
I don't think Professor Lavelle with expect us to know all of the elements yet, as none of our homework problems have required that either.
- Thu Oct 03, 2019 5:25 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: States of Matter
- Replies: 9
- Views: 709
Re: States of Matter
For the problems that we are currently solving, I don't think the states of matter make a difference.
- Wed Oct 02, 2019 10:25 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Molar Mass
- Replies: 10
- Views: 1125
Re: Molar Mass
Molar mass refers to the mass of one mole of the susbstance, and its units are g/mol. It is usually not given because you can figure it out from the periodic table by adding up the mass of each element in the compound.
- Wed Oct 02, 2019 10:22 pm
- Forum: Limiting Reactant Calculations
- Topic: limiting reactant
- Replies: 5
- Views: 390
Re: limiting reactant
As Sophia said, there is only one compound on the reactant side, so that must be the limiting reactant. No more product can be produced than what you start out with as reactants. Therefore, the theoretical yield corresponds to the maximum amount of product that can be produced given there are no imp...