Search found 53 matches
- Sun Dec 08, 2019 11:04 pm
- Forum: Student Social/Study Group
- Topic: most stable
- Replies: 6
- Views: 583
Re: most stable
Lone pairs are not necessarily all that is considered. As said, formal charge should be zero or whatever the original charge on the molecule is.
- Sun Dec 08, 2019 11:03 pm
- Forum: Student Social/Study Group
- Topic: amphoteric vs. amphiprotic
- Replies: 4
- Views: 459
Re: amphoteric vs. amphiprotic
Kind of off this, but on the final were the questions asking to identify the type of compound referring to identification of amphoteric or amphiprotic?
- Sun Dec 08, 2019 11:02 pm
- Forum: Student Social/Study Group
- Topic: Cyanide
- Replies: 5
- Views: 512
Re: Cyanide
Based on the number of electrons bonded, the cyanide should have a triple bond between carbon and nitrogen along with a lone pair on each atom.
- Sun Dec 08, 2019 11:01 pm
- Forum: Student Social/Study Group
- Topic: stoichiometric point and titrations
- Replies: 2
- Views: 302
Re: stoichiometric point and titrations
It was more just based on relative ideas on pH. Yes, it said titration but just knowing which one was the stronger acid/base could help you determine if the pH was greater than, less than, or equal to 7.
- Sun Dec 08, 2019 11:00 pm
- Forum: Student Social/Study Group
- Topic: Final
- Replies: 4
- Views: 451
Re: Final
The marshmallow review had a similar question. The main thing was that the nitrogen in cyanide is attached as the heme complex to the central iron.
- Sun Dec 01, 2019 10:20 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Acids Vs. Bases
- Replies: 11
- Views: 880
Re: Acids Vs. Bases
H+ concentration is the key to differentiating acids and bases as this provides the basis to determining the pH of the substance.
pH < 7 is acidic
pH > 7 is basic
pH < 7 is acidic
pH > 7 is basic
- Sun Dec 01, 2019 10:19 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Basic Acids and Bases Help
- Replies: 3
- Views: 277
Re: Basic Acids and Bases Help
The organic chemistry tutor is good ^ as well as khan academy videos on the subject. Chemistry libre texts is also a good online resource too.
- Sun Dec 01, 2019 10:17 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Textbook
- Replies: 5
- Views: 2124
Re: Textbook
Chapter 6 covers everything with regards to acids and bases.
- Wed Nov 27, 2019 11:25 pm
- Forum: Hybridization
- Topic: Sigma and Pi Bonds
- Replies: 21
- Views: 1067
Re: Sigma and Pi Bonds
In terms of bonds, the simples way to remember sigma and pi bonds is to differentiate by bond length:
single bond = 1 sigma bond
double bond = 1 sigma bond, 1 pi bond
triple bond = 1 sigma bond, 2 pi bonds
single bond = 1 sigma bond
double bond = 1 sigma bond, 1 pi bond
triple bond = 1 sigma bond, 2 pi bonds
- Wed Nov 27, 2019 11:23 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Cis and Trans
- Replies: 6
- Views: 494
Re: Cis and Trans
At least one tests, applying cis and trans should be either given in the question itself if drawing the structure or identifiable based on the structures given.
- Sun Nov 24, 2019 9:34 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Hydrogen Bonding
- Replies: 13
- Views: 717
Re: Hydrogen Bonding
Since hydrogen bonding requries partial positive/negative bonding between Hydrogen (partial positive) and N, O, F (partial negative, it is usually polar.
- Sun Nov 24, 2019 9:29 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: melting point
- Replies: 8
- Views: 644
Re: melting point
I'm not too sure, but single bonds have lower melting points than like triple bonds that have higher melting point.
- Sun Nov 24, 2019 9:25 pm
- Forum: Hybridization
- Topic: Electron Configuration and Hybridization
- Replies: 2
- Views: 233
Re: Electron Configuration and Hybridization
I'm not too sure what the connection is between these and hybridization. The most direct connection hybridization has is with molecular shape/structure.
- Sun Nov 24, 2019 9:16 pm
- Forum: Hybridization
- Topic: hybridization
- Replies: 5
- Views: 568
Re: hybridization
Hybridization does represent the blend of the resonance structures and refers to their molecular shapes (i.e. sp, sp2, sp3, etc.)
- Sun Nov 24, 2019 9:13 pm
- Forum: Hybridization
- Topic: Sigma and Pi bonds
- Replies: 13
- Views: 716
Re: Sigma and Pi bonds
sigma and pi bonds are simply labeled based on the bond type (single = 1 sigma, double = 1 sigma, 1 pi, triple = 1 sigma, 2 pi)
- Sun Nov 17, 2019 2:23 pm
- Forum: Hybridization
- Topic: Sigma and pi bonds
- Replies: 5
- Views: 537
Re: Sigma and pi bonds
I'm pretty sure we just need to know the conceptual basis behind sigma and pi bonds, not necessarily the hybridization.
- Sun Nov 17, 2019 2:22 pm
- Forum: Hybridization
- Topic: Pi vs Sigma Bonds
- Replies: 10
- Views: 655
Re: Pi vs Sigma Bonds
Sigma and pi bonds both involve the overlap of atomic orbitals in different ways, but to put it simply, pi bonds are weaker due to the fact that there is less overlap present normally than there is in sigma bonds.
- Sun Nov 17, 2019 2:20 pm
- Forum: Hybridization
- Topic: Specifics
- Replies: 3
- Views: 260
Re: Specifics
We should not need to based on our current knowledge of hybridization.
- Sun Nov 17, 2019 2:18 pm
- Forum: Hybridization
- Topic: Test?
- Replies: 6
- Views: 389
Re: Test?
Hybridization should not be included, but we will be expected to know all the various molecular shapes (linear, tetrahedral, etc.) along with bond angles that do relate to the hybridization
- Sun Nov 17, 2019 2:17 pm
- Forum: Hybridization
- Topic: Lone Pairs
- Replies: 3
- Views: 253
Re: Lone Pairs
Hybridized orbitals are basically a mix (or hybrid so to speak) of atomic orbitals.
- Mon Nov 11, 2019 12:10 am
- Forum: Lewis Structures
- Topic: Polar and Non polar covalent bonds in lewis structures
- Replies: 5
- Views: 352
Re: Polar and Non polar covalent bonds in lewis structures
I'm not too sure what you mean, but we are sometimes asked to indicate partial positive and negative charges, which is an indication of whether or not the bond is polar.
- Mon Nov 11, 2019 12:08 am
- Forum: Electronegativity
- Topic: Electronegativity between Oxygen and nitrogen
- Replies: 2
- Views: 491
Re: Electronegativity between Oxygen and nitrogen
It's because oxygen actually has 8 protons in its nucleus compared to nitrogen's 7, making oxygen have a greater attractive force towards a bonding pair.
- Mon Nov 11, 2019 12:05 am
- Forum: Resonance Structures
- Topic: how to draw
- Replies: 6
- Views: 450
Re: how to draw
Usually resonance structures are differentiated by a difference in bonds (single, double, triple) that can be rotated among the similar atoms to form the resonance structures.
- Mon Nov 11, 2019 12:04 am
- Forum: Resonance Structures
- Topic: Writing Out Resonance
- Replies: 3
- Views: 239
Re: Writing Out Resonance
I think we need to write it all out when it explicitly says to write out all resonance. Otherwise bracketed should be fine.
- Mon Nov 11, 2019 12:04 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Test Policy
- Replies: 6
- Views: 466
Re: Test Policy
I believe so. That is what most of us were told to do in reference to formal charges
- Mon Nov 11, 2019 12:03 am
- Forum: Octet Exceptions
- Topic: Limit to expanded octet
- Replies: 7
- Views: 800
Re: Limit to expanded octet
Expanded octet often is restrained to those with odd number of valence electrons
- Mon Nov 11, 2019 12:02 am
- Forum: Electronegativity
- Topic: Noble Gases
- Replies: 40
- Views: 12756
Re: Noble Gases
Noble gases are not included in the trend for electronegativity.
- Sun Nov 03, 2019 9:43 pm
- Forum: Dipole Moments
- Topic: Polarizability
- Replies: 1
- Views: 95
Re: Polarizability
I think we just need to know polarizability in terms of its relation to anions and polarizing power; basically periodic trends. Hope this helps
- Sun Nov 03, 2019 9:34 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: formal charge
- Replies: 5
- Views: 196
Re: formal charge
A more symmetrical distribution contributes to the overall stability of the molecule, indicating why formal charges closer to zero are more stable.
- Sun Nov 03, 2019 9:33 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: formal charge
- Replies: 4
- Views: 162
Re: formal charge
Formal charge is represented by the formula: FC = Ve- - (bonded + s/2) and is used for determining the most plausible resonance structures among other purposes.
- Sun Nov 03, 2019 9:32 pm
- Forum: Electronegativity
- Topic: Ionization energy and electronegativity
- Replies: 8
- Views: 797
Re: Ionization energy and electronegativity
Both ionization energy and electronegativity are related with ionization energy referring to how much energy is needed to remove an electron, while electronegativity refers to the relative strength of the pull of shared electrons unequally within a bond.
- Sun Nov 03, 2019 9:05 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic vs Covalent
- Replies: 14
- Views: 885
Re: Ionic vs Covalent
Ionic bonds are where electrons are fully transferred from one atom to another, while covalent bonds are strictly shared between atoms.
- Sun Oct 27, 2019 11:32 pm
- Forum: Properties of Light
- Topic: Light vs. Particles
- Replies: 2
- Views: 183
Re: Light vs. Particles
Particles: λ = h / (mv)
Light: c = λ v ---> E = hc/λ (derived from E = hv)
Light: c = λ v ---> E = hc/λ (derived from E = hv)
- Sun Oct 27, 2019 11:30 pm
- Forum: Properties of Light
- Topic: Value for C
- Replies: 8
- Views: 305
Re: Value for C
Usually, I just use 2.998 x 10^8 to improve accuracy and just round off for significant figures only after the final calculation.
- Sun Oct 27, 2019 11:29 pm
- Forum: Properties of Light
- Topic: p=mv
- Replies: 4
- Views: 159
Re: p=mv
p is momentum
m is mass in kg
v is velocity in m/s
p is measured in kg * (m/s)
m is mass in kg
v is velocity in m/s
p is measured in kg * (m/s)
- Sun Oct 27, 2019 11:27 pm
- Forum: Properties of Light
- Topic: Speed of light
- Replies: 13
- Views: 376
Re: Speed of light
speed of light is 2.998 x 10^8 m/s and this is utilized as waves are part of the light spectrum. Hope this helps!
- Sun Oct 27, 2019 11:25 pm
- Forum: Properties of Light
- Topic: All the formulas
- Replies: 5
- Views: 215
Re: All the formulas
c = lambda (v)
E = hv ---> E = hc / lambda
Hope this helps!
E = hv ---> E = hc / lambda
Hope this helps!
- Sun Oct 20, 2019 10:29 pm
- Forum: Properties of Light
- Topic: What are the units of hertz
- Replies: 41
- Views: 2117
Re: What are the units of hertz
Hertz refers to s^-1. This is justified by the fact that c = v λ; c is in units of m/s, λ is in units of m, therefore leaving v in units of s^-1.
- Sun Oct 20, 2019 10:22 pm
- Forum: Properties of Light
- Topic: Light as a wave
- Replies: 4
- Views: 213
Re: Light as a wave
The location of impact does not affect the number of photons, rather the energy of the photons (blue/violet in comparison to red/green). Hope this helps!
- Sun Oct 20, 2019 10:16 pm
- Forum: Properties of Light
- Topic: Which equations only work for light, and which for particles?
- Replies: 3
- Views: 253
Re: Which equations only work for light, and which for particles?
For the most part, it shouldn't be difficult to differentiate between which equation to use as you determine which value you are given in the problem then utilize the respective equation (either E = hv or E = pc). Hope this helps!
- Sun Oct 20, 2019 10:13 pm
- Forum: Properties of Light
- Topic: light regions
- Replies: 4
- Views: 178
Re: light regions
Not too sure, but our TA said to know at the very least the values that divide the ultraviolet region, visible light region, and infrared region since these are the most commonly utilized in calculations.
- Sun Oct 20, 2019 10:11 pm
- Forum: Properties of Light
- Topic: 1F.19
- Replies: 5
- Views: 225
Re: 1F.19
I'm not too sure what you mean by p-block metals, since p orbitals normally refer to the gaseous elements, but the s-block metals normally are reactive (become cations) in the sense that they are willing to bond with p-block elements to form a complete octet. Hope this helps!
- Sun Oct 13, 2019 10:40 pm
- Forum: Properties of Light
- Topic: Intensity & Amplitude
- Replies: 7
- Views: 465
Re: Intensity & Amplitude
There is a direct relationship between these two aspects that causes one to increase/decrease in relation to the corresponding increase/decrease of the other factor.
- Sun Oct 13, 2019 10:35 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Why do the orbitals of an atom only hold a certain amount of electrons?
- Replies: 7
- Views: 1054
Re: Why do the orbitals of an atom only hold a certain amount of electrons?
s, p, d, and f refer to specific types of orbitals that are found in elements. So these numbers simply represent the maximum amount of electrons that can occupy a space. Hope this helps!
- Sun Oct 13, 2019 10:26 pm
- Forum: Photoelectric Effect
- Topic: Confusion on equations
- Replies: 9
- Views: 377
Re: Confusion on equations
This is basically the same, but simply put, it is the same equation but is utilized based on the values given. If the wavelength is given, E = hc / lambda is ued. If the velocity is given, E = hv is used. Hope this helps!
- Sun Oct 13, 2019 10:12 am
- Forum: Trends in The Periodic Table
- Topic: electronegativity
- Replies: 10
- Views: 3328
Re: electronegativity
In terms of periodic trends, uhedlund described it pretty well. Just to be more specific, the trend displays that electronegativity increases from the bottom left corner of the periodic table to the upper right hand corner. This means that elements like Fluorine and Chlorine have an extremely high e...
- Sat Oct 12, 2019 8:42 pm
- Forum: Properties of Light
- Topic: How does x-ray crystallography work?
- Replies: 2
- Views: 103
Re: How does x-ray crystallography work?
I'm not too sure, but x-ray crystallography is the utilization of a crystalline structure to diffract x-rays in a beam and these help determine the three-dimensional structure. Hope this helps!
- Thu Oct 03, 2019 9:57 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: #E5 part b)
- Replies: 2
- Views: 145
Re: #E5 part b)
You need to include the answer achieved in part a in the part b calculation.
So, 1 / (1.2 x 10^-14 mol) represents the time in seconds.
All that needs to be done after is a conversion to time in years. Hope this helps!
So, 1 / (1.2 x 10^-14 mol) represents the time in seconds.
All that needs to be done after is a conversion to time in years. Hope this helps!
- Thu Oct 03, 2019 9:55 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Gaseous Mixtures
- Replies: 2
- Views: 216
Re: Gaseous Mixtures
I think for the sake of not complicating it, the book's intention is to just draw a distinction between those mixtures strictly including gases and those strictly including liquids. Gaseous solution seems contradictory in nature like Priscilla said.
- Thu Oct 03, 2019 9:47 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: textbook problem G.25
- Replies: 3
- Views: 174
Re: textbook problem G.25
So, we are given that the final moar concentration is 0.10 M and that you will have a volume of 10 mL diluted solution. We need to first calculate the number of molecules present in such a solution: 10 mL (0.10 mol / 1000 mL) (6.022 x 10^23 molecules / 1 mol) = 6.0 x 10^20 mlcls From here, all you n...
- Thu Oct 03, 2019 9:39 pm
- Forum: Empirical & Molecular Formulas
- Topic: F24
- Replies: 1
- Views: 286
Re: F24
I would balance the equation first: Ca Mg(Co3)2 --> MgO + CaO + 2 CO2 Then find the amount of moles of CO2 using the mass (10.04 g - 5.12 g = 4.92 g). Use the moles of CO2 to calculate the moles of MgCO3. Finally, use the moles of MgCO3 to calculate the mass of MgCO3 that remains after the decomposi...
- Thu Oct 03, 2019 9:31 pm
- Forum: Empirical & Molecular Formulas
- Topic: Mass Percentage Composition Rounding
- Replies: 3
- Views: 332
Re: Mass Percentage Composition Rounding
In terms of rounding, I usually write down a rounded percentage for the step, but keep the original unrounded number in my calculator. Then using these original calculated values in the final calculation, the results seem to be more accurate and add up to a value much closer to 100%.
- Thu Oct 03, 2019 9:25 pm
- Forum: Limiting Reactant Calculations
- Topic: Calculating Theoretical Yield
- Replies: 9
- Views: 408
Re: Calculating Theoretical Yield
I believe once you figure out which reagent is the limiting reagent, you must use the whole amount given in the problem for the limiting reagent calculation. So yes, the theoretical yield would be the same as the amount of the limiting reagent.