Search found 71 matches
- Fri Jan 15, 2021 10:58 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Changing pressure by adding gas
- Replies: 13
- Views: 49
Re: Changing pressure by adding gas
Adding an inert gas won't shift the reaction because an inert gas does not affect the concentrations of reactant and products.
- Fri Jan 15, 2021 10:56 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: adding heat
- Replies: 15
- Views: 49
Re: adding heat
It is favorable because endothermic reactions require heat to take place and when you add heat they are able to reach the activation energy to start the reaction more easily.
- Fri Jan 15, 2021 10:55 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Long term vs short term changes in conc.
- Replies: 6
- Views: 28
Re: Long term vs short term changes in conc.
I think we usually refer to the long term change because the question is already stating the short term change.
- Fri Jan 15, 2021 10:53 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: pKw
- Replies: 7
- Views: 42
Re: pKw
It changes depending on the temperature. However, the standard temperature is 25 degrees Celsius and at that temperature it is 10^-14.
- Fri Jan 15, 2021 10:51 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Gas
- Replies: 16
- Views: 63
Re: Gas
I think the question would specify the units. Lavelle also mentioned that we can use them interchangeably in this class because they are approximately equal.
- Wed Jan 06, 2021 7:08 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: solvent in equilibrium constants
- Replies: 8
- Views: 31
Re: solvent in equilibrium constants
Aqueous solutions are included, but solvents indicated by (l) aren't.
- Wed Jan 06, 2021 7:07 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K=1
- Replies: 6
- Views: 36
Re: K=1
It is rare for the concentrations of reactants and products to be equal.
- Wed Jan 06, 2021 7:06 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Q compared to K
- Replies: 6
- Views: 20
Re: Q compared to K
K does not change because it is a constant. If Q is greater than K, then you know more reactants will form to reach equilibrium and if Q is less than K, then you know that more products must be formed.
- Wed Jan 06, 2021 7:04 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: molar concentrations
- Replies: 5
- Views: 18
Re: molar concentrations
I think they would usually be given but if not they will probably give you the moles and the volume and then you would just have to divide in order to get the concentration.
- Wed Jan 06, 2021 7:02 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Homogeneous & Heterogeneous Reactions
- Replies: 4
- Views: 16
Re: Homogeneous & Heterogeneous Reactions
Homogeneous reactions just have all of the reactants and products in the same phase whereas heterogeneous reactions do not. When calculating the equilibrium constant, you will just have to make sure that you do not include liquids and solids in the calculation.
- Wed Jan 06, 2021 7:00 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Net Ionic Equations
- Replies: 4
- Views: 23
Re: Net Ionic Equations
Either way they would cancel out but it would be the simplest in terms of calculations to use net ionic equations.
- Mon Dec 07, 2020 8:30 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Does pH indicate strength of an acid?
- Replies: 26
- Views: 130
Re: Does pH indicate strength of an acid?
Yes, the lower the pH, the stronger the acid.
- Mon Dec 07, 2020 8:29 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: H3O+ versus H+
- Replies: 16
- Views: 111
Re: H3O+ versus H+
I think they are both basically the same thing.
- Mon Dec 07, 2020 8:26 pm
- Forum: Lewis Acids & Bases
- Topic: HClO3
- Replies: 3
- Views: 44
Re: HClO3
I think it's a strong acid.
- Mon Dec 07, 2020 8:25 pm
- Forum: Lewis Acids & Bases
- Topic: Calculations for Acids and Bases
- Replies: 5
- Views: 38
Re: Calculations for Acids and Bases
I don't think so. I think that's what we start with in 14B.
- Mon Dec 07, 2020 8:24 pm
- Forum: Lewis Acids & Bases
- Topic: Water
- Replies: 62
- Views: 476
Re: Water
Water can act as either an acid or a base since it is amphoteric.
- Mon Dec 07, 2020 8:22 pm
- Forum: Lewis Acids & Bases
- Topic: sapling #6
- Replies: 19
- Views: 99
Re: sapling #6
It has a carboxyl group which makes it an acid.
- Wed Dec 02, 2020 6:25 pm
- Forum: Naming
- Topic: Oxidation number of ligands
- Replies: 11
- Views: 83
Re: Oxidation number of ligands
I think we should have a general idea of the oxidation numbers of common ligands but I think that will just come automatically from doing homework/practice problems.
- Wed Dec 02, 2020 6:21 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Sapling Week 9 HW Question 2
- Replies: 11
- Views: 97
Re: Sapling Week 9 HW Question 2
There are four Br atoms bound to the Fe atom and the coordination number is the number of bonds to the central transition metal so it is 4.
- Wed Dec 02, 2020 6:19 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Charges on Metals
- Replies: 3
- Views: 37
Re: Charges on Metals
We can figure that out by looking at the periodic table and seeing which column it is in. For example, Na is in the first column so it has a +1 charge.
- Wed Dec 02, 2020 6:17 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordination Numbers in Molecules
- Replies: 3
- Views: 32
Re: Coordination Numbers in Molecules
I think it only refers to the central atom.
- Wed Dec 02, 2020 6:17 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Determining Coordination Numbers
- Replies: 5
- Views: 44
Re: Determining Coordination Numbers
The coordination number is basically the number of bonds attached to the central metal.
- Wed Nov 25, 2020 11:53 am
- Forum: Hybridization
- Topic: Carbon double bond
- Replies: 3
- Views: 37
Re: Carbon double bond
I think that since there are pi bonds and those bonds can't rotate, it has to stay on the same plane.
- Wed Nov 25, 2020 11:50 am
- Forum: Hybridization
- Topic: Sp3d or dsp3
- Replies: 22
- Views: 850
Re: Sp3d or dsp3
I don't think it really matters since both are correct. I think sp3d is more of the convention though.
- Wed Nov 25, 2020 11:49 am
- Forum: Hybridization
- Topic: e density
- Replies: 30
- Views: 127
Re: e density
Yes. Every bond and lone pair is a region of electron density. However, it doesn't matter if the bond is a double or triple bond. It is still one region of electron density either way.
- Wed Nov 25, 2020 11:47 am
- Forum: Hybridization
- Topic: More than 6 electron densities
- Replies: 5
- Views: 41
Re: More than 6 electron densities
I'm pretty sure there are but I don't think we learn about them in this class.
- Wed Nov 25, 2020 11:46 am
- Forum: Hybridization
- Topic: Sapling Week 7 & 8 HW Question 11
- Replies: 14
- Views: 108
Re: Sapling Week 7 & 8 HW Question 11
There are 3 bonds and one lone pair which basically means that there are 4 groups. This means the answer would be sp3 because there is one s orbital and 3 p orbitals which makes up 4 groups.
- Wed Nov 25, 2020 11:44 am
- Forum: Hybridization
- Topic: Hybridization Clarification
- Replies: 9
- Views: 61
Re: Hybridization Clarification
Hybridization is basically mixing atomic orbitals to form new hybrid orbitals.
- Wed Nov 18, 2020 11:05 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: Ion-Dipole vs Hydrogen Bonding
- Replies: 3
- Views: 24
Re: Ion-Dipole vs Hydrogen Bonding
I think the order you listed is correct.
- Wed Nov 18, 2020 11:04 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: London Dispersion Force
- Replies: 5
- Views: 18
Re: London Dispersion Force
Yes, all molecules have LDFs as temporary dipoles are often formed.
- Wed Nov 18, 2020 11:03 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: Intermolecular Forces of CHI3 and CHF3
- Replies: 5
- Views: 35
Re: Intermolecular Forces of CHI3 and CHF3
I think it is because iodine is much larger so there are stronger london dispersion forces since neither of them have dipole dipole or hydrogen bonding.
- Wed Nov 18, 2020 11:02 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: Ionic Bond vs. Hydrogen Bonding
- Replies: 10
- Views: 39
Re: Ionic Bond vs. Hydrogen Bonding
Ionic bonds are stronger than hydrogen bonds. This means that it would take more energy to break them and therefore they would have a higher boiling point.
- Wed Nov 18, 2020 11:00 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: What exactly is a dipole? [ENDORSED]
- Replies: 16
- Views: 115
Re: What exactly is a dipole? [ENDORSED]
A dipole is basically where there is a partial positive or negative because electrons are shared unequally.
- Wed Nov 18, 2020 10:59 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: Hydrogen Bonding
- Replies: 5
- Views: 39
Re: Hydrogen Bonding
It technically can form two hydrogen bonds but I don't think it is very likely.
- Wed Nov 18, 2020 10:57 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: Magnitude of Hydrogen and Dispersion Forces
- Replies: 4
- Views: 39
Re: Magnitude of Hydrogen and Dispersion Forces
Yes, but I think all you really need to know are the hydrogen bonds are much stronger than dispersion forces.
- Wed Nov 18, 2020 10:56 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: H-Bonding clarification
- Replies: 7
- Views: 90
Re: H-Bonding clarification
The hydrogen just needs to be bonded to N O or F. The lone pairs on N O or F are not relevant.
- Thu Nov 12, 2020 4:42 pm
- Forum: Electronegativity
- Topic: Electronegativity Difference for Covalent and Ionic Bonds
- Replies: 6
- Views: 37
Re: Electronegativity Difference for Covalent and Ionic Bonds
I think you have to examine it more carefully and look at other characteristics if the bond is in between these two values but I don't think it is likely that he will give us questions like that at this point.
- Thu Nov 12, 2020 4:39 pm
- Forum: Electronegativity
- Topic: determining electronegativity
- Replies: 31
- Views: 252
Re: determining electronegativity
It increases to the right and decreases going down. You can also remember that fluorine is the most electronegative element to help you remember this trend.
- Thu Nov 12, 2020 4:37 pm
- Forum: Lewis Structures
- Topic: Lewis structures with Noble gases
- Replies: 5
- Views: 37
Re: Lewis structures with Noble gases
Expanded octets can occur from the period 3 or after because the d orbital starts.
- Thu Nov 12, 2020 4:33 pm
- Forum: Lewis Structures
- Topic: Double Bonds
- Replies: 11
- Views: 85
Re: Double Bonds
You would place the double bond where it would result in the lowest formal charges.
- Thu Nov 12, 2020 4:32 pm
- Forum: Lewis Structures
- Topic: NHF2
- Replies: 7
- Views: 20
Re: NHF2
No, we don't need to worry about shape for now.
- Thu Nov 12, 2020 4:28 pm
- Forum: Lewis Structures
- Topic: Radicals
- Replies: 12
- Views: 38
Re: Radicals
Radicals just have one unpaired electron so if there are an odd number of electrons, you can see that it is a radical.
- Tue Nov 03, 2020 3:13 pm
- Forum: Lewis Structures
- Topic: sides
- Replies: 12
- Views: 115
Re: sides
I don't think the side matters. You just need the correct number of electrons and bonds.
- Tue Nov 03, 2020 3:12 pm
- Forum: Lewis Structures
- Topic: Differences in Bond Length
- Replies: 6
- Views: 68
Re: Differences in Bond Length
This is because single bonds have less electrons so they are not as strong and cannot pull the atoms as close to one another. However, a double bond is stronger and can pull the atoms closer together, making the bond shorter.
- Tue Nov 03, 2020 3:10 pm
- Forum: Lewis Structures
- Topic: Different Lewis Structures
- Replies: 6
- Views: 49
Re: Different Lewis Structures
I think they are different because the electrons are still technically in different positions.
- Tue Nov 03, 2020 3:08 pm
- Forum: Lewis Structures
- Topic: Brackets for Anions
- Replies: 6
- Views: 43
Re: Brackets for Anions
Brackets are used so that the charge of the entire molecule can be displayed right outside of the bracket. Since they are used to show the charge, they are used for both anions and cations.
- Tue Nov 03, 2020 3:07 pm
- Forum: Lewis Structures
- Topic: Line in place of paired dots
- Replies: 8
- Views: 43
Re: Line in place of paired dots
I think we should use lines to show bonds and dots for lone pairs as that is the proper notation.
- Tue Nov 03, 2020 3:04 pm
- Forum: Lewis Structures
- Topic: charge by square bracket
- Replies: 8
- Views: 61
Re: charge by square bracket
The charge represents the charge of the entire molecule. Since the charge of the molecule was -1, he put a minus. This allows for one to understand the number of electrons being represented in the lewis structure.
- Wed Oct 28, 2020 5:33 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: position units
- Replies: 19
- Views: 111
Re: position units
You should covert to meters as that is the SI unit and will be consistent with the other measurements.
- Wed Oct 28, 2020 5:30 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Change in Velocity Uncertainty
- Replies: 4
- Views: 67
Re: Change in Velocity Uncertainty
You multiply by 2 when there is a +/- because the uncertainty can be double the amount due to this. You use the given uncertainty if it gives you a percentage without the +/- or doesn’t explicitly tell you to double the value.
- Wed Oct 28, 2020 5:26 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Max Vs. Min Uncertainty
- Replies: 5
- Views: 70
Re: Max Vs. Min Uncertainty
I don't think you change anything when plugging numbers into problems for maximum and minimum uncertainty. The solution to these problems is always >= when plugging numbers into the equation so if it asks for the minimum, you simply put in the answer you get when you solve the equation.
- Wed Oct 28, 2020 5:24 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Multiplying Uncertainty of Speed by two to find deltaV
- Replies: 4
- Views: 51
Re: Multiplying Uncertainty of Speed by two to find deltaV
You do multiply by 2 because the uncertainty is double the amount when it could either be plus or minus. There was actually a problem in the solution in the textbook for that problem.
- Wed Oct 28, 2020 5:21 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Heisenberg Indeterminacy (Uncertainty) Equation
- Replies: 5
- Views: 106
Re: Heisenberg Indeterminacy (Uncertainty) Equation
There is an inverse relationship between the certainty of position for electrons and momentum for electrons because knowing the speed makes it harder to know the position. In order to know the speed, photons must hit the particle which moves the particle’s position, making it harder to know the posi...
- Wed Oct 21, 2020 9:00 am
- Forum: Einstein Equation
- Topic: Homework Problem 6
- Replies: 4
- Views: 31
Re: Homework Problem 6
For determining the number of spectral lines that could appear, you just have to think about which energy levels it could drop down to. There are only 4 energy levels below it so only 4 spectral lines could appear. The wavelength range would also be the difference in the wavelength when it is a drop...
- Wed Oct 21, 2020 8:56 am
- Forum: Properties of Electrons
- Topic: Post Assesment Module: Wave Properties of Electrons and the De Broglie Equation Number 35
- Replies: 6
- Views: 76
Re: Post Assesment Module: Wave Properties of Electrons and the De Broglie Equation Number 35
This is because the wavelengths for larger objects are so small that they are basically undetectable.
- Wed Oct 21, 2020 8:53 am
- Forum: Properties of Light
- Topic: Midterm
- Replies: 42
- Views: 390
Re: Midterm
I think it’s multiple choice, closed note and we have around 50 minutes to take the test. I don’t think there is any partial credit and I am pretty sure that some questions are weighted differently than others. We will also be using Respondus on our main device with the test on it and Zoom on anothe...
- Wed Oct 21, 2020 8:48 am
- Forum: Properties of Light
- Topic: Difference between E=hv and E=hc/v?
- Replies: 9
- Views: 91
Re: Difference between E=hv and E=hc/v?
I think you mean E=hc/λ and that is basically a combination of E=hv and C=λv. This is because v can also be represented as c/λ.
- Wed Oct 21, 2020 8:46 am
- Forum: Properties of Light
- Topic: Tips to memorize wavelengths of the spectrum
- Replies: 7
- Views: 67
Re: Tips to memorize wavelengths of the spectrum
I think that we just have to know that the visible region is between 400 and 700 nm and red is 700 while violet is 400. I think we should also know that smaller wavelengths usually fall under ultraviolet and longer wavelengths usually fall under infrared.
- Wed Oct 21, 2020 8:43 am
- Forum: Properties of Light
- Topic: Relationship between intensity and amplitude
- Replies: 3
- Views: 47
Re: Relationship between intensity and amplitude
This is true. I think this was mentioned in a module but I think you mainly should just know that as the intensity increases, the amplitude increases as well for this class.
- Wed Oct 14, 2020 11:36 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Molarity test question
- Replies: 8
- Views: 86
Re: Molarity test question
Yes, you should be able to solve for any of the variables in the equation which can be done by plugging in the other values that you know.
- Wed Oct 14, 2020 11:30 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: mmol
- Replies: 14
- Views: 154
Re: mmol
It is 10^-3 of a mole.
- Wed Oct 14, 2020 11:27 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Molar Mass and Molecular Mass Difference?
- Replies: 21
- Views: 255
Re: Molar Mass and Molecular Mass Difference?
They are basically the same but molar mass is measured in grams while molecular mass is measured in amu.
- Wed Oct 14, 2020 11:23 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: E23 Confused
- Replies: 4
- Views: 85
Re: E23 Confused
The ratio is actually 1:1 between moles of Cu ions and CuBR2 so you don’t have to divide the value by 2.
- Mon Oct 12, 2020 5:13 pm
- Forum: Properties of Light
- Topic: Quantized
- Replies: 11
- Views: 65
Re: Quantized
Quantized is basically where there are discrete values so it is not continuous.
- Mon Oct 12, 2020 5:09 pm
- Forum: Properties of Light
- Topic: Quanta and Photons
- Replies: 19
- Views: 172
Re: Quanta and Photons
A transferable unit is basically the smallest unit of water that can be transferred to another object like the bucket in this example. That would be one water molecule.
- Sat Oct 10, 2020 10:08 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Avogadro's #
- Replies: 31
- Views: 363
Re: Avogadro's #
It is used when you are asked to convert to the number of molecules, atoms or particles.
- Mon Oct 05, 2020 3:43 pm
- Forum: Balancing Chemical Reactions
- Topic: Moles and Chemical Equations
- Replies: 12
- Views: 145
Re: Moles and Chemical Equations
There are 2 moles of H20 but 4 moles of H.
- Mon Oct 05, 2020 3:35 pm
- Forum: Balancing Chemical Reactions
- Topic: Law of Conservation with Exothermic/Endothermic Reactions
- Replies: 11
- Views: 131
Re: Law of Conservation with Exothermic/Endothermic Reactions
I don't think heat would be factored in because it does not fall under any of the four states of matter (solid, liquid, gas, aqueous).
- Mon Oct 05, 2020 3:32 pm
- Forum: Balancing Chemical Reactions
- Topic: Stoichemetric Coeffiecients
- Replies: 12
- Views: 141
Re: Stoichemetric Coeffiecients
I think you would always balance the equations so that the coefficients are in the lowest whole number ratio possible. If there was a coefficient of 8.5, I think you would just multiply every coefficient in the reaction by 2 so that this coefficient becomes the whole number 17.
- Mon Oct 05, 2020 3:28 pm
- Forum: Limiting Reactant Calculations
- Topic: Fundamentals M5
- Replies: 7
- Views: 82
Re: Fundamentals M5
In order to figure out with reactant is an excess, you will have to use the coefficients next to the reactants to see what the ratio between the reactants should be. In this reaction the ratio is 6 moles of CIO2 to 2 moles of BrF3. If you have 12 moles of Cl02, you should have 4 moles of BrF3. Since...
- Mon Oct 05, 2020 3:21 pm
- Forum: Balancing Chemical Reactions
- Topic: Balancing chemical equations involving combustion
- Replies: 15
- Views: 117
Re: Balancing chemical equations involving combustion
Yes because O2 is always a reactant in a combustion reaction.