Search found 31 matches

by Vienna Cimetta 1L
Sun Jun 10, 2018 3:19 pm
Forum: Lewis Acids & Bases
Topic: Weak vs strong acids [ENDORSED]
Replies: 7
Views: 364

Re: Weak vs strong acids [ENDORSED]

Regarding what we need to know about the strong acids I think it's important to be able to say which are stronger than others. This would include using the bond length (longer = weaker, more likely to give off H+) and whether the anion is more stable (more electronegative atoms pull electrons in and...
by Vienna Cimetta 1L
Sun Jun 10, 2018 3:12 pm
Forum: Bronsted Acids & Bases
Topic: H3O vs H2O
Replies: 5
Views: 316

Re: H3O vs H2O

When he spoke about H30+ being formed he was talking about putting an acid into water, whereas when H2O is formed he was talking about neutralization reactions where when you but an acid and base together they form water and a salt.
by Vienna Cimetta 1L
Sun Jun 10, 2018 3:07 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Chelating complex
Replies: 7
Views: 186

Re: Chelating complex

Is there a minimum amount of ligands required in order to have this happen?
by Vienna Cimetta 1L
Sun Jun 03, 2018 4:56 pm
Forum: Hybridization
Topic: List of the different shapes
Replies: 6
Views: 229

Re: List of the different shapes

Also in discussion my TA mentioned that when they ask for the geometry of the molecule, they want you to include the lone pairs, but if they ask for the molecular structure, they want you to not include the lone pairs and just describe what would be observed. So just beware that questions could ask ...
by Vienna Cimetta 1L
Sun Jun 03, 2018 4:49 pm
Forum: Hybridization
Topic: σ vs π bond tips thread
Replies: 5
Views: 177

Re: σ vs π bond tips thread

Generally double bonds are stronger than single bonds, and pi bonds are more likely to break than sigma bonds. Because pi bonds do not allow for rotation, they are often the first to break during a reaction. If you see a double bond in a molecule, just know one is a sigma bond and one is a pi bond. ...
by Vienna Cimetta 1L
Sun Jun 03, 2018 4:41 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Significance of Coordination Number?
Replies: 7
Views: 260

Re: Significance of Coordination Number?

Yeah I'm pretty sure he just stressed it to have us understand the term and what to look for if the coordination number is asked on a test.
by Vienna Cimetta 1L
Sun May 27, 2018 3:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Regions of electron density
Replies: 7
Views: 243

Re: Regions of electron density

Lone pairs do count as an area of electron density, but in the VSEPR model you only consider the actual atoms attached to the atom when looking at it's structure and naming it. That being said, lone pairs on the central atom will impact the structure because of electron repulsion.
by Vienna Cimetta 1L
Sun May 27, 2018 3:14 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angle
Replies: 6
Views: 209

Re: Bond Angle

I'm pretty sure you just have to memorize the bond angles are this point. Some are straight forward, like when you see a linear structure you know its 180, but other than that I think its just best to memorize the odd ones like when its less than 109.5. Also some structures will have more than one b...
by Vienna Cimetta 1L
Sun May 27, 2018 3:12 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Types of Bonds
Replies: 6
Views: 183

Re: Types of Bonds

A sigma bond is a single bond and the rest from there are pi bonds, because there can only be one sigma bond between two molecules. Therefore, double and triple bonds are pi bonds.
by Vienna Cimetta 1L
Sun May 20, 2018 1:44 pm
Forum: Lewis Structures
Topic: Exception to Lewis Structure?
Replies: 4
Views: 151

Re: Exception to Lewis Structure?

It's because Cl has the ability to access the 3d-orbtial and electrons can go into this orbital and exceed the octet.
by Vienna Cimetta 1L
Sun May 20, 2018 1:39 pm
Forum: Dipole Moments
Topic: Dipole relevance
Replies: 4
Views: 135

Re: Dipole relevance

I'm pretty sure induced dipoles occur when one molecule with a permanent dipole repels another molecule's electrons and causes a fluctuation in the other molecule's electron density that creates an instantaneous dipole moment.
by Vienna Cimetta 1L
Sun May 20, 2018 1:15 pm
Forum: Lewis Structures
Topic: Creating a Lewis Stucture
Replies: 8
Views: 251

Re: Creating a Lewis Stucture

Honestly i think it all just comes down to trial and error. Once you have the central atom you just have to place the others in a way to find the lowest formal charge. If you see something an element with a +1 charge, try to take a lone pair from an adjacent element and create a double bond. Sometim...
by Vienna Cimetta 1L
Sun May 13, 2018 4:33 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Calculating formal charges
Replies: 5
Views: 194

Re: Calculating formal charges

I just think of it as 1. taking the number of valence electrons (which can be found on the periodic table) and 2. taking this number and subtracting the number of electrons surrounding the specific element (where a bond would only really be one electron). This way its only a two step calculation and...
by Vienna Cimetta 1L
Sun May 13, 2018 4:29 pm
Forum: Octet Exceptions
Topic: Octet exceptions and Formal charges.
Replies: 6
Views: 362

Re: Octet exceptions and Formal charges.

Yeah you should check to make sure you find the structure with a formal change closest to zero, because they said last class that will be the only correct answer. When they ask for a lewis diagram, they want the most stable one.
by Vienna Cimetta 1L
Sun May 13, 2018 4:25 pm
Forum: Resonance Structures
Topic: Resonance Structures and Formal charges
Replies: 7
Views: 288

Re: Resonance Structures and Formal charges

So if there are multiple different ways to draw a molecule, where each as a different formal charge (like the examples in class), are these not resonance?
by Vienna Cimetta 1L
Sun May 13, 2018 4:18 pm
Forum: Quantum Numbers and The H-Atom
Topic: Homework problem 2.93
Replies: 2
Views: 179

Re: Homework problem 2.93

Wow i feel stupid... thank you, i had no idea what i was doing wrong
by Vienna Cimetta 1L
Sun May 06, 2018 10:46 pm
Forum: Trends in The Periodic Table
Topic: Electron Affinity
Replies: 3
Views: 156

Re: Electron Affinity

So if an element has a high electron affinity, would the energy released when an electron is added also be high? The higher the electron affinity, the larger amount of energy released when an electron is added?
by Vienna Cimetta 1L
Sun May 06, 2018 10:39 pm
Forum: Quantum Numbers and The H-Atom
Topic: Homework problem 2.93
Replies: 2
Views: 179

Homework problem 2.93

Would someone be able to explain the answers to this problem? Especially where C = Na+ and D = Cl- I thought cations were supposed to be smaller in size from their parent element, but in the book is shows Na+ as larger than Na. Same idea with Cl, I thought anions were normally larger in size from th...
by Vienna Cimetta 1L
Sun May 06, 2018 10:31 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Exceptions for Electron Configuartions
Replies: 5
Views: 213

Re: Exceptions for Electron Configuartions

Also it's important to note that this trend is the same for the next periods down in the d-block. So Ag and Au will do the same (nd10 ns1).
by Vienna Cimetta 1L
Mon Apr 30, 2018 12:12 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Uncertainty Equation significance
Replies: 4
Views: 120

Re: Uncertainty Equation significance

The uncertainty principle is rooted in the fact that the process of observation influences the outcome of the experiment, and that there is a limit to the accuracy to which we can know the exact momentum and position of a particle.
by Vienna Cimetta 1L
Mon Apr 30, 2018 12:06 am
Forum: DeBroglie Equation
Topic: De Brogile's equation [ENDORSED]
Replies: 4
Views: 222

Re: De Brogile's equation [ENDORSED]

The equation can only be used for something that has a rest mass. A photon of light does not, and therefore the equation cannot be used.
by Vienna Cimetta 1L
Mon Apr 30, 2018 12:04 am
Forum: DeBroglie Equation
Topic: Ek= 0 [ENDORSED]
Replies: 3
Views: 182

Re: Ek= 0 [ENDORSED]

Ek = 0 when the minimum amount of energy needed to eject an electron is provided by the light wavelength. Therefore, all the energy from the photon is used to eject the electron and there is no excess energy.
by Vienna Cimetta 1L
Sun Apr 22, 2018 8:37 pm
Forum: *Black Body Radiation
Topic: Black Body? [ENDORSED]
Replies: 13
Views: 1205

Re: Black Body? [ENDORSED]

Do you guys think we would be asked any questions on this topic? Or is it just another concept to know for future reference
by Vienna Cimetta 1L
Sun Apr 22, 2018 8:24 pm
Forum: Properties of Light
Topic: amplitude and intensity
Replies: 11
Views: 339

Re: amplitude and intensity

Also I think it's important to note that if any question says that "brightness" is increased or decreased, they are talking about the amplitude of a given wavelength, not the frequency. Just so you know how it might be applied in the test.
by Vienna Cimetta 1L
Sun Apr 22, 2018 8:17 pm
Forum: Properties of Electrons
Topic: electron mass
Replies: 15
Views: 561

Re: electron mass

also i'm pretty sure they said the mass will be given on the front page of the test, so don't worry about memorizing it
by Vienna Cimetta 1L
Fri Apr 13, 2018 12:41 am
Forum: Empirical & Molecular Formulas
Topic: Formula steps
Replies: 4
Views: 205

Re: Formula steps

To find the empirical formula you first have to find the mass composition of each element, then find the moles of each element, and divide the moles of each element by the element with the smallest number of moles. If needed, round these values found to the nearest whole number to get the molar rati...
by Vienna Cimetta 1L
Fri Apr 13, 2018 12:31 am
Forum: Balancing Chemical Reactions
Topic: Another Way to Balance
Replies: 7
Views: 264

Re: Another Way to Balance

It's always easiest to start with the element that occurs the least in the reaction, moving your way to the elements that occur the most. Also,if an element stands on it's own leave it until the last, because it is an easy fix to just had a coefficient in front that will balance out the element on e...
by Vienna Cimetta 1L
Fri Apr 13, 2018 12:25 am
Forum: Limiting Reactant Calculations
Topic: Knowing if it's Limiting Reactions
Replies: 6
Views: 296

Re: Knowing if it's Limiting Reactions

Sometimes the question will just ask what the mass of a particular product will be in a specific reaction. In this case, you have to find what the limiting reagent is because this will dictate what the mass of the product will be. Therefore, it won't always directly ask you to find the limiting reac...
by Vienna Cimetta 1L
Fri Apr 13, 2018 12:18 am
Forum: Balancing Chemical Reactions
Topic: Memorizing the charges of ions
Replies: 3
Views: 167

Re: Memorizing the charges of ions

Elements on the left of the periodic table will have positive chargers because they are more likely to lose electrons, and elements on the left of the periodic table will have negative chargers because they are more likely to gain electrons.
by Vienna Cimetta 1L
Fri Apr 13, 2018 12:12 am
Forum: Empirical & Molecular Formulas
Topic: Molecular to Empirical [ENDORSED]
Replies: 12
Views: 473

Re: Molecular to Empirical [ENDORSED]

Also just as a side note, if visual diagram of the compound is given often it's easier to start by naming the molecular formula, then reduce the numbers to the empirical formula. I assume if one of the elements is only present once the empirical formula would be the same, since you have to only have...
by Vienna Cimetta 1L
Thu Apr 12, 2018 11:57 pm
Forum: Molarity, Solutions, Dilutions
Topic: Fundamentals problem G7
Replies: 2
Views: 113

Re: Fundamentals problem G7

I'm pretty sure you need to find 5.45% of 510g (to find the mass of KNO3), then the remainder would be the mass of H20 (subtract the mass of KNO3 from 510g). This would give you the mass of each component to use.

Go to advanced search