Search found 31 matches
- Mon Jun 04, 2018 6:38 pm
- Forum: Lewis Acids & Bases
- Topic: Strength between 2 weak/strong acids/bases
- Replies: 5
- Views: 798
Strength between 2 weak/strong acids/bases
If given two weak acids, two strong acids, two weak bases, or two strong bases, how could you tell which one is stronger/weaker?
- Mon Jun 04, 2018 6:31 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligands
- Replies: 3
- Views: 428
Ligands
Can someone explain to me exactly what a ligand is? I'm confused...
- Mon Jun 04, 2018 6:26 pm
- Forum: Dipole Moments
- Topic: dipole moments
- Replies: 9
- Views: 1668
Re: dipole moments
I think they were probably talking about the strength. The polar bonds may not cancel if one is stronger than the other.
- Mon Jun 04, 2018 6:23 pm
- Forum: Properties of Light
- Topic: Memorizing formulas test 2
- Replies: 16
- Views: 1660
Re: Memorizing formulas test 2
We don't have to memorize formulas, but I do find that doing a bunch of practice problems helps with memorization (although it may not be very fun).
- Mon Jun 04, 2018 6:17 pm
- Forum: Lewis Acids & Bases
- Topic: weak acids
- Replies: 3
- Views: 405
Re: weak acids
I wrote down carbonic acid (H2CO3) and benzoic acid (C6H5COOH). Apparently, when there is a carbon present the acid is weaker. In addition, compared to strong acids which dissociate completely, weak acids only dissociate ~1%.
- Mon Jun 04, 2018 6:14 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Helpful Chart
- Replies: 18
- Views: 1479
Re: Helpful Chart
Thank you so much!
- Mon Jun 04, 2018 6:12 pm
- Forum: Hybridization
- Topic: Lone Pairs
- Replies: 5
- Views: 582
Re: Lone Pairs
I believe so because there are 4 areas of electron density
- Fri May 25, 2018 12:30 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angle
- Replies: 10
- Views: 1104
Re: Bond Angle
I believe we need to know some general angles: tetrahedral - 109.5º, linear - 180º, trigonal planar - 120º (I'm not too sure if we need to know octahedral or trigonal bipyramidal). Outside of that, we probably only need to know some trends. For example, although trigonal pyramidal has a shape simila...
- Fri May 25, 2018 12:20 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: shape of water
- Replies: 8
- Views: 1155
Re: shape of water
I think shape is named based on the amount of bonds there are. However, the amount of lone pairs do alter the shape of the molecule. Water, because the central atom is only bonded to 2 other atoms, cannot be named trigonal pyramidal (trigonal pyramidal implies there are 3 bonds to the central atom a...
- Fri May 25, 2018 12:07 pm
- Forum: Ionic & Covalent Bonds
- Topic: Formal charge?
- Replies: 12
- Views: 1381
Re: Formal charge?
Formal Charge = (# of valence e-) – (# of lone pair e-) – (1/2)(# of bonded e-)
- Wed May 09, 2018 4:10 pm
- Forum: Properties of Light
- Topic: Problem 1.69
- Replies: 1
- Views: 301
Re: Problem 1.69
Because we are given the work energy in eV so converting it to Joules and calculating for its frequency is helpful. We know that the laser the secret agents want to use is going to have the same or higher frequency (calculate frequency for both lasers to figure out which one should be used). After f...
- Wed May 09, 2018 4:04 pm
- Forum: Properties of Light
- Topic: Quiz 2 Question #6
- Replies: 2
- Views: 462
Re: Quiz 2 Question #6
I'm not too sure how you got 4.28x10^13m, when entering this into a calculator I got 42.9m. However, in order to turn meters into nm, all you would have to do is divide it by 10^-9. Essentially, 42.9m x [1nm/(10^-9m)] = 4.29x10^10 nm. I hope this helps.
- Wed May 09, 2018 3:55 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: HW Problem 2.39
- Replies: 2
- Views: 340
Re: HW Problem 2.39
I'm assuming we only need to know when atoms are in their ground state (and the configuration for ground state) or when they are not in their ground state.
- Mon May 07, 2018 4:30 pm
- Forum: Properties of Light
- Topic: Test 2 Question 4
- Replies: 8
- Views: 884
Re: Test 2 Question 4
Lilianna, I believe the answer to this problem is 2.84x10^-19 J
- Mon May 07, 2018 4:28 pm
- Forum: Empirical & Molecular Formulas
- Topic: Test #1 Question 7 mass percentage
- Replies: 2
- Views: 671
Re: Test #1 Question 7 mass percentage
Yeah, this is a tricky question because the amount of O2 that reacted was not given. First I divided both amounts of CO2 and H2O formed by their respective molar masses and found that they were equal to each other (both created 0.178 moles). Using this knowledge and the fact that O2 was present I cr...
- Tue May 01, 2018 5:41 pm
- Forum: Ionic & Covalent Bonds
- Topic: Help on 3.9 (b) [ENDORSED]
- Replies: 2
- Views: 347
Re: Help on 3.9 (b) [ENDORSED]
[Ar]3d^6 would be [Ar]3d^(6)4s^(2) if it did not have a charge of 2+. [Ar]3d^(6)4s^(2) is Fe, so [Ar]3d^6 is Fe^(2+). I hope this helps.
- Tue May 01, 2018 5:32 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: How detailed should the configurations be?
- Replies: 3
- Views: 469
Re: How detailed should the configurations be?
I think you only need to know the shorthand, but being familiar with the notation of sub-levels may come in handy later.
- Mon Apr 30, 2018 4:14 pm
- Forum: DeBroglie Equation
- Topic: De Brogiles wavelength
- Replies: 4
- Views: 703
Re: De Brogiles wavelength
Yes, I think you would have to use the molar mass and convert that to kg per unit(or atom). I don't know how else a person would be able to get the mass in order to plug it into the equation λ=h/mv.
- Mon Apr 30, 2018 4:10 pm
- Forum: Photoelectric Effect
- Topic: Test 2 final question [ENDORSED]
- Replies: 15
- Views: 1813
Re: Test 2 final question [ENDORSED]
There is always a one-to-one ratio in the interactions between a photon and an electron, so when 1000 photons are used, 1000 electrons are emitted.
- Mon Apr 30, 2018 4:05 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Atomic Spectra
- Replies: 1
- Views: 296
Re: Atomic Spectra
When calculating for frequency, just make the value positive. The negative only indicates whether or not the energy is getting absorbed or emitted. It is not necessary in an equation for frequency.
- Mon Apr 30, 2018 4:03 pm
- Forum: Photoelectric Effect
- Topic: What is work function? [ENDORSED]
- Replies: 15
- Views: 5626
Re: What is work function? [ENDORSED]
The Work function (threshold energy) is the energy needed to expel one electron from metal in a vacuum.
- Mon Apr 30, 2018 3:57 pm
- Forum: Photoelectric Effect
- Topic: light problem
- Replies: 2
- Views: 570
Re: light problem
So right now, you have the answer in meters. Nanometers is 10^(-9) meters so you can calculate (4.32x10^-7m)x(1nm/[10^-9]m). Which would give you 432.x10^-9m or 432nm. Hope this helps.
- Mon Apr 30, 2018 3:48 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: 3d and 4s orbitals
- Replies: 3
- Views: 379
Re: 3d and 4s orbitals
When getting to higher energy levels, the energy levels get closer and closer together, so the 4s and 3d levels are really close. At first, the 4s level is lower than 3d (so it will fill up first), but once there are 20+ electrons, the 3d level shifts down slightly and ends up at a lower energy leve...
- Sat Apr 21, 2018 4:41 pm
- Forum: DeBroglie Equation
- Topic: DeBrogile Module
- Replies: 6
- Views: 516
Re: DeBrogile Module
I believe it needs to be converted. What is the answer supposed to be?
- Thu Apr 12, 2018 12:28 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Which mass of oxygen should be used? [ENDORSED]
- Replies: 23
- Views: 3195
Re: Which mass of oxygen should be used? [ENDORSED]
Since the last digit in an answer is typically an estimate I don't believe it matters.
- Thu Apr 12, 2018 12:21 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Units - L or mL? [ENDORSED]
- Replies: 15
- Views: 4589
Re: Units - L or mL? [ENDORSED]
I believe it is preferred to give an answer in Liters rather than mL unless asked otherwise
- Thu Apr 12, 2018 12:16 pm
- Forum: SI Units, Unit Conversions
- Topic: Chemistry Review Section E
- Replies: 4
- Views: 427
Re: Chemistry Review Section E
I think 1 mol of something = 6.022x10^23 units of that something
- Fri Apr 06, 2018 8:00 pm
- Forum: Limiting Reactant Calculations
- Topic: Module 3: Limiting Reactant Calculations Problem 21 [ENDORSED]
- Replies: 2
- Views: 236
Re: Module 3: Limiting Reactant Calculations Problem 21 [ENDORSED]
Ohh thanks! I missed that
- Fri Apr 06, 2018 4:52 pm
- Forum: Limiting Reactant Calculations
- Topic: Module 3: Limiting Reactant Calculations Problem 21 [ENDORSED]
- Replies: 2
- Views: 236
Module 3: Limiting Reactant Calculations Problem 21 [ENDORSED]
After doing this problem several times over, I never end up with any of the given answers. The problem gives 0.750 g C6H9Cl3, 1.000 kg AgNO3, and their molar masses: 187.50 g/mol and 169.88 g/mol respectively. Chemical Formula: C6H9Cl3 + 3(AgNO3) ---> AgCl + C6H9(NO3)3. I found that there are 4x10^3...
- Fri Apr 06, 2018 4:33 pm
- Forum: Empirical & Molecular Formulas
- Topic: F.25
- Replies: 2
- Views: 218
Re: F.25
In the solutions manual, the answer given is C2H8N2.
- Fri Apr 06, 2018 1:36 pm
- Forum: Empirical & Molecular Formulas
- Topic: Which mass of Hydrogen should I use?
- Replies: 3
- Views: 941
Re: Which mass of Hydrogen should I use?
I believe the last digit in the numerical value is an "estimate", so I don't believe you would lost points if the answer you proposed is off in the hundredths place.