Search found 49 matches
- Sun Dec 08, 2019 5:22 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: polarisability
- Replies: 3
- Views: 467
Re: polarisability
We never had to use the formula to do any calculations. if anything this would be a conceptual question,
- Sun Dec 08, 2019 5:14 pm
- Forum: Resonance Structures
- Topic: Best Resonance Structure
- Replies: 5
- Views: 490
Re: Best Resonance Structure
All the resonance structures should have the same charge because the only thing that is changing is the placement of the bonds.
- Sun Dec 08, 2019 5:09 pm
- Forum: Polyprotic Acids & Bases
- Topic: Calculating pH of polyprotic acid
- Replies: 2
- Views: 287
Re: Calculating pH of polyprotic acid
We would calculate it regularly because the second dissociation does not cause a large enough change in the pH for there to be a need to consider it.
- Sun Dec 08, 2019 5:05 pm
- Forum: Conjugate Acids & Bases
- Topic: 6A.3
- Replies: 2
- Views: 284
Re: 6A.3
The acid molecule will react with water to produce H30+ and a conjugate base which can reaccept the proton.
- Sun Dec 08, 2019 5:02 pm
- Forum: Lewis Acids & Bases
- Topic: Lewis Acids
- Replies: 3
- Views: 388
Re: Lewis Acids
Lewis acids are molecules that are often positively charged that would bond to an atom with a lone pair such as H+.
- Sun Dec 08, 2019 5:01 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: enthalpy?
- Replies: 3
- Views: 233
Re: enthalpy?
No we will not be tested on anything related to enthalpy.
- Sun Dec 08, 2019 4:58 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: pH Calculation
- Replies: 3
- Views: 198
Re: pH Calculation
For strong acids like HCl you would assume full dissociation and so you would just take the negative log of the molarity given because that is how many H30+ ions will be produced as well.
- Sun Dec 08, 2019 4:55 pm
- Forum: Bronsted Acids & Bases
- Topic: NH3
- Replies: 5
- Views: 1141
Re: NH3
NH3 is a molecule that is amphoteric so it can act as a base or acid. Therefore, you can not assume anything.
- Sun Dec 01, 2019 11:58 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Explain VSEPR conceptually
- Replies: 12
- Views: 770
Re: Explain VSEPR conceptually
VSEPR provides a 3D model for a molecule based on the regions of electron density.
- Sun Dec 01, 2019 11:56 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Linear VSEPR model
- Replies: 21
- Views: 1256
Re: Linear VSEPR model
You determine VSEPR based on the regions of electron density, and lone pairs attached to the central atom are considered another region of electron density.
- Sun Dec 01, 2019 11:53 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Test 2
- Replies: 6
- Views: 470
Re: Test 2
I believe the test will be handed back in discussion this week with your grade on it.
- Sun Dec 01, 2019 11:52 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bent vs linear
- Replies: 56
- Views: 4036
Re: Bent vs linear
A molecule is bent rather than linear because when a lone pair has more repulsion than that of another atom, so even though the other two atoms in the bent shape are closer together, this is still a more optimal shape.
- Sun Dec 01, 2019 11:50 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Breaking of pi and sigma bonds
- Replies: 4
- Views: 348
Re: Breaking of pi and sigma bonds
Sigma bonds allow for rotation while pi bonds do not, so the pi bonds would break only.
- Sun Nov 24, 2019 11:59 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone Pairs on Cenrtral Atom
- Replies: 11
- Views: 582
Re: Lone Pairs on Cenrtral Atom
Lone pairs have the highest repulsion, so even if the attached atoms are closer together when there is a lone pair, the molecule is more stable.
- Sun Nov 24, 2019 11:57 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: melting point
- Replies: 8
- Views: 604
Re: melting point
If a bond broke, the melting point would decrease because that means less energy is required to break the total bonds in the molecule.
- Sun Nov 24, 2019 11:55 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: energy
- Replies: 1
- Views: 147
Re: energy
The lone pairs have the highest repulsion, so the molecule is more stable if the atoms are further from the lone pairs because repulsion increases potential energy rapidly after a certain point.
- Sun Nov 24, 2019 11:53 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR formula
- Replies: 5
- Views: 308
Re: VSEPR formula
Yes we need to know the bond angles based on the molecular shape.
- Sun Nov 24, 2019 11:52 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: electron and molecular geometry of H20
- Replies: 3
- Views: 223
Re: electron and molecular geometry of H20
The electron arrangement of H20 would be tetrahedral, but the molecular shape would be bent/angular.
- Sun Nov 10, 2019 11:04 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizability for Final
- Replies: 2
- Views: 215
Re: Polarizability for Final
As previously stated, I would know the general trends of polarizability and polarizing power.
- Sun Nov 10, 2019 11:03 pm
- Forum: Resonance Structures
- Topic: octet v. expanded octet
- Replies: 5
- Views: 313
Re: octet v. expanded octet
You would not draw an expanded octet for a single atom. For a molecule, you would show an expanded octet by surpassing the octet rule such as an atom having 5 covalent bonds.
- Sun Nov 10, 2019 11:00 pm
- Forum: Bond Lengths & Energies
- Topic: London Forces
- Replies: 6
- Views: 323
Re: London Forces
Yes, because all molecules have electrons and these electrons can congregate by chance.
- Sun Nov 10, 2019 10:58 pm
- Forum: Electronegativity
- Topic: Electron affinity
- Replies: 6
- Views: 701
Re: Electron affinity
Electronegativity and electron affinity increase towards the upper right.
- Sun Nov 10, 2019 10:56 pm
- Forum: Electronegativity
- Topic: Atom size
- Replies: 22
- Views: 3154
Re: Atom size
Atomic radius increases in the opposite direction from electronegativity.
- Sun Nov 03, 2019 11:36 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Magnetic Quantum Number
- Replies: 3
- Views: 186
Re: Magnetic Quantum Number
it is always plus or minus 1/2 and you cannot find the spin orientation, rather you essentially assign it yourself.
- Sun Nov 03, 2019 11:35 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: 4th Quantum Number
- Replies: 3
- Views: 156
Re: 4th Quantum Number
There is no way to calculate or find the fourth quantum number. As long as two electrons in the same orbital do not have the same spin you are good.
- Sun Nov 03, 2019 11:34 pm
- Forum: DeBroglie Equation
- Topic: 1B. 21
- Replies: 5
- Views: 327
Re: 1B. 21
That information has nothing to do with the calculations because they give you the actual mass of the baseball.
- Sun Nov 03, 2019 11:32 pm
- Forum: DeBroglie Equation
- Topic: unit of wavelength
- Replies: 5
- Views: 508
Re: unit of wavelength
when you work with the equation, you use meters, but often you convert the final answer into nanometers because it is more visually appealing this way.
- Sun Nov 03, 2019 11:28 pm
- Forum: DeBroglie Equation
- Topic: 1B.15 c)
- Replies: 1
- Views: 140
Re: 1B.15 c)
basically you use the equation Ek = work + 1/2xmassxvelocity^2 and plug in the answer from part b as the value for the work function. Then you should get around 8.8x10^-9 m which you convert to nm.
- Sun Oct 27, 2019 5:39 pm
- Forum: Lewis Structures
- Topic: Lone pair
- Replies: 8
- Views: 370
Re: Lone pair
A lone pair is just the pair of electrons not used in the chemical bond, which is why they are lonely.
- Sun Oct 27, 2019 5:34 pm
- Forum: Ionic & Covalent Bonds
- Topic: Double bond placement
- Replies: 15
- Views: 796
Re: Double bond placement
Double bond placement does not need to be in a specific spot as long as the octet rule is fulfilled for all the atoms.
- Sun Oct 27, 2019 5:27 pm
- Forum: Ionic & Covalent Bonds
- Topic: Resonance
- Replies: 10
- Views: 379
Re: Resonance
Resonance means that a molecule can have a certain bond in multiple different areas while still being the same molecule. Lewis structures can only show one of these formations at a time.
- Sun Oct 27, 2019 5:24 pm
- Forum: Lewis Structures
- Topic: Reasoning for the octet
- Replies: 3
- Views: 254
Re: Reasoning for the octet
Atoms are the most stable with a full valence shell, and as you stated, the s and p orbitals can hold a total of 8 electrons, so the octet being filled is the goal.
- Sun Oct 27, 2019 5:20 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Water molecules
- Replies: 9
- Views: 916
Re: Water molecules
Water molecules use both Hydrogen atoms to form a hydrogen bond and not both to form one bond.
- Mon Oct 21, 2019 12:00 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Best Way To Study?
- Replies: 56
- Views: 3346
Re: Best Way To Study?
i think attending lecture and taking good notes is a good way to study. After, review the textbook and consolidate the information into a more cohesive "cheat sheet" in order to highlight the specific topics.
- Sun Oct 20, 2019 11:59 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Formulas or Experiments
- Replies: 2
- Views: 93
Re: Formulas or Experiments
I think we should know the experiments in order to be able to understand the concepts behind the formulas.
- Sun Oct 20, 2019 11:58 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Homework Problem 1A #3
- Replies: 3
- Views: 146
Re: Homework Problem 1A #3
the extent of change refers to the wave's slope, which correlates directly with frequency.
- Sun Oct 20, 2019 11:55 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Memorizing Wavelengths and Frequencies?
- Replies: 2
- Views: 75
Re: Memorizing Wavelengths and Frequencies?
I agree I would just memorize which series goes with which level and the types of wavelengths that are associated with them. I would also know the range of each wave type.
- Sun Oct 20, 2019 11:50 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Homework 1A.9
- Replies: 1
- Views: 76
Re: Homework 1A.9
You basically use the formula wavelength=speed of light x frequency in order to find the frequency and wavelength as needed. To find the energy of the photon use the formula E=Planck's constant x frequency. Based on the wavelength, you can determine what the activity is.
- Sun Oct 13, 2019 9:37 pm
- Forum: Properties of Electrons
- Topic: wave-like vs particle-like
- Replies: 2
- Views: 62
Re: wave-like vs particle-like
Photons act as a wave but on a much smaller scale act as individual entities.
- Sun Oct 13, 2019 9:27 pm
- Forum: Photoelectric Effect
- Topic: Wavelength, Frequency, and Intensity
- Replies: 7
- Views: 1093
Re: Wavelength, Frequency, and Intensity
intensity is the number of photons emitted and frequency is the number of waves during a certain period
- Sun Oct 13, 2019 9:25 pm
- Forum: Photoelectric Effect
- Topic: Wavelength, Frequency, and Intensity
- Replies: 7
- Views: 1093
Re: Wavelength, Frequency, and Intensity
wavelength and frequency are inversely related so when wavelength increases, frequency decreases, which means there is less intensity coming from the wave, so less energy.
- Sun Oct 13, 2019 9:21 pm
- Forum: Photoelectric Effect
- Topic: Waves
- Replies: 4
- Views: 192
Waves
What is the relationship between wavelength, frequency and amplitude?
- Sun Oct 13, 2019 9:12 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Atom Spectroscopy
- Replies: 2
- Views: 156
Re: Atom Spectroscopy
I am not sure but so far we have only learned how to complete these problems using the equation derived from the experiment that used hydrogen atoms.
- Sun Oct 06, 2019 11:55 pm
- Forum: Balancing Chemical Reactions
- Topic: H 1
- Replies: 6
- Views: 578
H 1
It appears that balancing the chemical equation Cu 1 SO 2 S
CuO 1 S would be simple if we could just add another O atom to the
product side: Cu 1 SO 2 S CuO 1 S 1 O. (a) Why is that balancing
procedure not allowed? (b) Balance the equation correctly.
I am confused about part a.
CuO 1 S would be simple if we could just add another O atom to the
product side: Cu 1 SO 2 S CuO 1 S 1 O. (a) Why is that balancing
procedure not allowed? (b) Balance the equation correctly.
I am confused about part a.
- Sun Oct 06, 2019 11:54 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: G 25
- Replies: 7
- Views: 386
G 25
Practitioners of the branch of alternative medicine known as homeopathy claim that very dilute solutions of substances can have an effect. Is the claim plausible? To explore this question, suppose that you prepare a solution of a supposedly active substance, X, with a molar concentration of 0.10 mol...
- Sun Oct 06, 2019 11:52 pm
- Forum: SI Units, Unit Conversions
- Topic: Unit Conversions
- Replies: 6
- Views: 348
Re: Unit Conversions
I believe that we should know the conversions as it will help with the efficiency of our test taking.
- Sun Oct 06, 2019 11:50 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: G 11
- Replies: 2
- Views: 106
G 11
A medical researcher investigating the properties of intravenous solutions prepared a solution containing 0.278 m C6H12O6 (glucose). What volume of solution should the researcher use to provide 4.50 mmol C6H12O6? I'm not sure whether the answer is 0.016 or 0.02. How do we know how many sig figs to r...
- Sun Oct 06, 2019 11:47 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: E 17
- Replies: 6
- Views: 767
Re: E 17
Thank you for answering my question
- Sun Oct 06, 2019 11:44 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: E 17
- Replies: 6
- Views: 767
E 17
Which sample in each of the following pairs contains the
greater number of moles of atoms? (a) 75 g of indium or 80 g of
tellurium; (b) 15.0 g of P or 15.0 g of S; (c) 7.36 3 10 27 atoms of
Ru or 7.36 3 10 27 atoms of Fe.
greater number of moles of atoms? (a) 75 g of indium or 80 g of
tellurium; (b) 15.0 g of P or 15.0 g of S; (c) 7.36 3 10 27 atoms of
Ru or 7.36 3 10 27 atoms of Fe.