## Search found 60 matches

Sun Jan 17, 2021 11:02 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE Box Units
Replies: 6
Views: 16

### ICE Box Units

Is it possible to create and do the ICE box with mols and not mol.L-1? If so, how would that work with the equilibrium values?
Sun Jan 17, 2021 11:00 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Initial Concentrations
Replies: 7
Views: 26

### Initial Concentrations

How do we know when we are suppose to put the actual values of initial concentrations and not as 0 as seen in Sapling hw #10? I was confused as to why we put the initial values for both reactant and product.
Sun Jan 17, 2021 10:55 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: When would K be unchanged?
Replies: 31
Views: 63

### Re: When would K be unchanged?

Temperature is the only condition that could change the value of K. Every other condition changes we've learned so far does not affect the value of K because the system reacts in a way to minimize the effect of said changes.
Sun Jan 17, 2021 10:50 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Units to know
Replies: 11
Views: 24

### Units to know

What are other units, that mean the same, that could be used in equilibrium concentrations besides mol.L-1 and bar?
Sun Jan 17, 2021 10:48 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: C in ICE Box
Replies: 19
Views: 53

### C in ICE Box

How do we know when the Change in equilibrium is negative or positive for products/reactants?
Sun Jan 10, 2021 2:55 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Change in Conc
Replies: 8
Views: 20

### Change in Conc

Does a change in concentration have or not have an effect on the system? Will there ever be a time when a change in conc changes K?
Sun Jan 10, 2021 2:37 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Delta H and its affect
Replies: 5
Views: 20

### Delta H and its affect

How do the values of delta H influence the way we determine how there's a shift in equilibrium when there's an increase in temp and vice versa? In other words, what do negative and positive values of delta H mean for the reaction?
Sun Jan 10, 2021 12:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Picking Value when doing Quadratic Equation
Replies: 10
Views: 29

### Picking Value when doing Quadratic Equation

How do I know which x value to choose when I have solved for both values of x when I use the quadratic equation?
Sun Jan 10, 2021 12:22 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: I in ICE Chart
Replies: 11
Views: 34

### I in ICE Chart

When we are writing down the Initial concentration, is there ever a time that products will not equal 0?
Sun Jan 10, 2021 12:19 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kc calc with Cubic Equations
Replies: 1
Views: 11

### Kc calc with Cubic Equations

Are all the cases of cubic equations going to have small values of x where we have to approximate? If not, what is a measurement of knowing when the x is too small and we need to approximate?
Thu Dec 17, 2020 2:12 am
Forum: Hybridization
Topic: Hybridization of 2p and 2p2
Replies: 2
Views: 9

### Hybridization of 2p and 2p2

What exactly is 2p^2? I saw it on my lecture notes and I am unsure about what that means? Is that a different energy level than 2p or what exactly is it taking into account?
Thu Dec 17, 2020 2:10 am
Forum: Hybridization
Topic: Hybridization
Replies: 2
Views: 9

### Hybridization

I am a bit confused on the rules of hybridization. Do we have to fill up all of 2s before we move onto p?
Thu Dec 17, 2020 2:05 am
Forum: Identifying Acidic & Basic Salts
Topic: Determining Acids or Bases (Number based)
Replies: 2
Views: 26

### Determining Acids or Bases (Number based)

For most of the Sapling homework, we had to identify whether the numbers or compounds given were acids or bases.R Regarding the numbers, is there a rule that we can abide to when we determine whether it is acidic or basic? Or is the easiest way is by using the formulas of H+ and OH-?
Thu Dec 17, 2020 2:01 am
Forum: *Titrations & Titration Calculations
Topic: Polyprotic Acids and Bases
Replies: 3
Views: 51

### Polyprotic Acids and Bases

What is a polyprotic acid and base? and What do they do?
Sat Dec 12, 2020 8:30 pm
Forum: Hybridization
Topic: Electron Promotion and Hybridization
Replies: 1
Views: 24

### Electron Promotion and Hybridization

What is meant when they ask to draw box diagrams to show electron promotion and hybridization? What exactly is electron promotion?
Sun Dec 06, 2020 10:17 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Oxidation #
Replies: 6
Views: 43

### Oxidation #

How do we find the oxidation numbers? I am still a bit confused on how we find them and my PLF session talked about it, but very quickly and I still don't fully get it.
Sun Dec 06, 2020 10:08 pm
Forum: Amphoteric Compounds
Topic: Amphoteric Compound Acid/Base Character
Replies: 4
Views: 13

### Re: Amphoteric Compound Acid/Base Character

An Amphoteric compound acid/base is going to be weak, seeing that it can react as either a base or an acid. This also just means that the behavior of the compound depends a lot more on the stronger base/acid it is reacting with.
Sun Dec 06, 2020 10:00 pm
Forum: Shape, Structure, Coordination Number, Ligands
Replies: 8
Views: 55

Dentate is talking about the binding sites of ligands. Something I would use to remember this is seeing that dentate and donate is almost spelled the same/sound similar. (After all, ligands donate e-)
Sun Dec 06, 2020 9:49 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Definition of Ligand
Replies: 8
Views: 53

### Definition of Ligand

In the Sapling textbook, the definition of a ligand states that it acts as a lewis base by donating e-. This means that in a structure, all atoms that are not the central atom are considered Ligands? I'm a little confused on what a ligand is now, so can someone please clarify.
Sun Dec 06, 2020 9:44 pm
Forum: Naming
Topic: Prefixes
Replies: 5
Views: 43

### Prefixes

What prefixes are we expected to know for the naming of compounds?
Sun Nov 29, 2020 10:23 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Repulsion Strength
Replies: 1
Views: 15

### Repulsion Strength

Is there any repulsion strength between bonding-bonding PR? If it's a bond, how can it have repulsion strength? Or does it just reduce the repulsion strength, but not actually have repulsion?
Sun Nov 29, 2020 10:19 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar/Nonpolar Bonds/Molecules
Replies: 2
Views: 23

### Polar/Nonpolar Bonds/Molecules

What is the difference between polar/nonpolar bonds and polar/nonpolar molecules?
Sun Nov 29, 2020 10:17 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sapling #7
Replies: 3
Views: 32

### Sapling #7

One of the answers to the question of which one was polar was CH2CL2. When it is drawn, it looks like it would be non-polar and that there would no zero electric dipole. Can someone please explain why is it polar and why the dipoles do not cancel?
Sun Nov 29, 2020 10:12 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sapling 17
Replies: 3
Views: 41

### Sapling 17

The question asked to draw three possible Lewis structures for C3H4, but none of them were resonance structures, but why is this? It seems like one of them could have been, so why was that not an acceptable answer?
Sun Nov 29, 2020 10:10 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Delocalized Pi Bond
Replies: 3
Views: 36

### Delocalized Pi Bond

In the homework, a hint for a problem stated "Delocalized π bonds occur when π orbitals extend over more than two atoms", but I'm still a bit confused when it talks about it being a pi orbital? Does it just mean there are more than a single bond between two atoms?
Sun Nov 22, 2020 10:39 pm
Forum: Resonance Structures
Topic: Resonance Structures and Energy
Replies: 21
Views: 98

### Re: Resonance Structures and Energy

We want to be able to get to a Lewis structure with the least formal charge, always. This is because they'd had the least amount of energy, thus making them more stable and we want that! Also, it is important to remember that we want to always draw these lewis structures on tests
Sun Nov 22, 2020 10:21 pm
Forum: Hybridization
Topic: Pi and Sigma Bonds
Replies: 10
Views: 85

### Re: Pi and Sigma Bonds

Covalent bonds include both sigma and pi bonds. And yes, sigma bonds are in single bonds, sigma and pi are in double bonds, and so forth.
Sun Nov 22, 2020 10:11 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: Polarizablity
Replies: 10
Views: 80

### Polarizablity

What exactly is meant by polarizability? I know that it has to do with London forces, but I am a bit confused on what role is has on this type of force.
Sun Nov 22, 2020 10:07 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: H20 Bent Structure
Replies: 14
Views: 107

### Re: H20 Bent Structure

H20 is bent because the two lone electron pairs that are on one side of the molecule cause a repulsion on the hydrogen atoms attached to the oxygen molecule. The repulsion is ultimately what induces the tetrahedral shape. I visualize it as each lone pair having the energy to push down (or up) on the...
Sun Nov 22, 2020 10:01 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: Instantaneous Dipoles
Replies: 5
Views: 24

### Instantaneous Dipoles

Why are two nearby rod-shaped molecules stronger than when there are two nearby spherical molecules?
Sun Nov 15, 2020 8:55 pm
Forum: Dipole Moments
Topic: Strength of Dipole-Dipole vs Induced Dipole-Dipole
Replies: 4
Views: 16

### Re: Strength of Dipole-Dipole vs Induced Dipole-Dipole

Even though they are similar in strength, one of the UAs said dipole-dipole is stronger than dipole-induced dipole. I don't think we need to know that specificity for the midterm, but I just wanted to add on to previous comments.
Sun Nov 15, 2020 6:28 pm
Forum: Coordinate Covalent Bonds
Topic: Covalent Bond Character
Replies: 7
Views: 56

### Covalent Bond Character

I'm still confused about what it means when an ionic bond has some covalent bond character. The professor talked about it, but can someone please explain what this means and how it works.
Sun Nov 15, 2020 6:11 pm
Forum: Lewis Structures
Topic: Expanded Valence Shells
Replies: 2
Views: 15

### Expanded Valence Shells

During one of the professor's lecture, he states that P, S, and Cl can accommodate more than 8 valence e-. Then he says it is because atoms in period 3 or higher have d-orbitals that allow them to accommodate. Does this relate to the drawing of Lewis Structures, like when there are some atoms that c...
Sun Nov 15, 2020 6:00 pm
Forum: Lewis Structures
Topic: Drawing Lewis Structures on Midterm
Replies: 31
Views: 151

### Re: Drawing Lewis Structures on Midterm

Adding on, during a PLF session, I learned about Skeletal/Line structures, is there a possibility this may be on the midterm or are we just expected to draw the Lewis Structure with the lest F.C.?
Sun Nov 15, 2020 5:21 pm
Forum: Resonance Structures
Topic: Formal Charge
Replies: 11
Views: 77

### Formal Charge

When doing formal charges, do we know it is at the best Lewis structure when the atom with the least electronegativity (the atom in the middle) equals 0? Is that an indication that we could stop or do we just kind of stop when the formal charges of everything is at its lowest?
Sun Nov 08, 2020 11:40 pm
Forum: Dipole Moments
Topic: Hydrogen bonds
Replies: 9
Views: 207

### Re: Hydrogen bonds

Hydrogen bonding occurs between an attraction of a hydrogen atom to an electronegative atom like N, O, or F. H atoms will be "automatically" attracted to these atoms in other molecules.
Sun Nov 08, 2020 11:20 pm
Forum: Trends in The Periodic Table
Topic: Ionization Energy
Replies: 7
Views: 23

### Re: Ionization Energy

The second ionization energy is greater than the first because once an electron is removed, the other electrons are held tighter since there is one less electron contributing to the negative repulsion.
Sun Nov 08, 2020 11:15 pm
Forum: Lewis Structures
Topic: Lewis Acid vs. Lewis Base
Replies: 5
Views: 41

### Re: Lewis Acid vs. Lewis Base

Because carbon is the central atom, it accepts electrons. Even though both O are negative, CO2 is still partially positive and the double bonds are able to break. The best way to visualize this up is to draw reactions with CO2.
Sun Nov 08, 2020 10:52 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: E-Configuration
Replies: 3
Views: 16

### E-Configuration

As I'm reviewing past topics, I still find myself confused about 4s coming before 3d, but then there are cases where 3d comes before 4s. I'm not sure if I wrote my notes incorrectly, but for Ca it was [Ar]4s^2, but for Sc it was [Ar]3d^14s^2. Is there a reason why this rules seems to change for diff...
Sun Nov 08, 2020 10:45 pm
Forum: Trends in The Periodic Table
Topic: memorizing trends
Replies: 14
Views: 57

### Re: memorizing trends

Going off of trends on the periodic table, what are different ways that they could be described instead of just saying from left to right or up and down. I remember one of the questions on the practice Respondus quiz for this week asked about a trend, but the wording of the answers were very confusi...
Sun Nov 01, 2020 11:38 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configurations
Replies: 2
Views: 29

### Electron Configurations

Can someone please explain why is it that 4s comes before 3d?
Sun Nov 01, 2020 11:31 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Minimum Uncertainty
Replies: 3
Views: 59

### Minimum Uncertainty

A question on Sapling asked us to find the minimum uncertainty. My question is is there a maximum uncertainty or is there only ever a minimum uncertainty? I feel confused just because of the word "minimum". Is there a reason why it's called minimum?
Sun Nov 01, 2020 11:23 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: N,L,mL
Replies: 3
Views: 34

### N,L,mL

When we are given what n, l, and ml, how would we know how many electrons there are?
Sun Nov 01, 2020 11:17 pm
Forum: Trends in The Periodic Table
Topic: Oxygen vs Nitrogen and Fluorine
Replies: 4
Views: 38

### Oxygen vs Nitrogen and Fluorine

There was a question on Sapling that asked, "Identify the reasons why oxygen has a lower ionization energy than both Nitrogen and Fluorine." Can someone please clarify why the answers were what they were?
Sun Nov 01, 2020 11:11 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg's Equation, final minus initial or initial minus final?
Replies: 10
Views: 91

### Re: Rydberg's Equation, final minus initial or initial minus final?

To follow up on her question,I still get confused when it asks about n2 and n1. Going by the logic of the comments above, this means that n2 is the final state and n1 is the initial state, correct? Or would it be the other way around?
Sun Oct 25, 2020 11:06 pm
Forum: Properties of Electrons
Topic: Circular Standing Wave
Replies: 2
Views: 30

### Re: Circular Standing Wave

The waves represent the movement of electrons surrounding a nucleus. Electrons can move in waves. These wave patterns must align with each other (usually represented by the variable "n") and if their energies mismatch, then there is no allowed energy level. I am also confused on this topic...
Sun Oct 25, 2020 10:23 pm
Forum: Properties of Electrons
Topic: orbitals
Replies: 3
Views: 27

### Re: orbitals

Adding on to her question, how much about orbitals should we know? Are we responsible for knowing the details of s, p, d, and f orbitals and that being it?
Sun Oct 25, 2020 10:19 pm
Forum: DeBroglie Equation
Topic: De Broglie's Derived Eq
Replies: 3
Views: 33

### De Broglie's Derived Eq

Should we know how De Broglie derived lambda=h/p or would we be fine with knowing that h is Plank's constant, p is mass x velocity and lambda is wavelength?
Sun Oct 25, 2020 10:15 pm
Forum: Properties of Electrons
Topic: Wave Properties and Conceptual
Replies: 1
Views: 29

### Wave Properties and Conceptual

What are some conceptual aspects regarding Wave Properties that might come up on the midterm?
Sun Oct 25, 2020 10:00 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect-Work Function
Replies: 4
Views: 36

### Photoelectric Effect-Work Function

I was working on an example problem and I had to use the formula, E(hv)=(work function) + Ek, but I was confused as to why we had to use this formula and how I know what number is the Work Function. Can someone please explain what Work Function means when it comes to the Photoelectric Effect.
Sun Oct 18, 2020 9:32 pm
Forum: Einstein Equation
Topic: m vs nm
Replies: 66
Views: 441

### Re: m vs nm

I asked my PLF a similar question and she explained that if needed to 1) it'll explicitly tell us and 2) in the past, he's given a sheet with formulas and we can refer to it. I'm not sure how that's going to work with the test being online though.
Sun Oct 18, 2020 9:29 pm
Forum: Properties of Electrons
Topic: protons and electrons
Replies: 33
Views: 191

### Re: protons and electrons

Protons and neurons have similar masses, whereas electrons are much smaller and therefore weigh less. Protons and neurons reside in the center of the atom and electrons are floating/orbiting around it.
Sun Oct 18, 2020 9:23 pm
Forum: Trends in The Periodic Table
Topic: Octet Expansion
Replies: 5
Views: 175

### Re: Octet Expansion

Any element from Period 3 and below are able to expand, meaning elements like C, N, O are not part of that rule because they are exceptions to it. Reminder to always be careful when you are working with these elements and their surrounding electrons.
Sun Oct 18, 2020 8:39 pm
Forum: Einstein Equation
Topic: e=hv used for particles?
Replies: 9
Views: 225

### Re: e=hv used for particles?

Avagrado's number is used when working with moles, so what the professor taught Week 1. For E=hv, the constant that is used is Plank's constant.
Sun Oct 18, 2020 8:28 pm
Forum: Properties of Light
Topic: Units to know
Replies: 4
Views: 34

### Units to know

There are problems that require you to covert units and the professor has gone over all the units, but my question is whether we have to memorize all of them or which ones should we memorize and which ones don't we have to worry about as much?
Sun Oct 11, 2020 9:57 pm
Forum: Limiting Reactant Calculations
Topic: Theoretical Yield/ Percent Yield
Replies: 5
Views: 62

### Re: Theoretical Yield/ Percent Yield

The limiting reactant is what determines how much product would be formed, so that is the first step in trying to find the theoretical yield. The percent yield uses both the theoretical and actual yield, so if not ask to be found, then the actual yield will be provided.
Sun Oct 11, 2020 1:43 am
Forum: Molarity, Solutions, Dilutions
Topic: Formulas involved in Determining Solution Concentration
Replies: 8
Views: 86

### Formulas involved in Determining Solution Concentration

There are two formulas integrated into this section of the review. One of them being M=n/v and M(initial)V(initial)=M(final)V(final). I get a bit confused when I try to figure out what formula is appropriate to use for what problem. Are there any key words or any way for me to quickly recognize what...
Sun Oct 11, 2020 1:37 am
Forum: Balancing Chemical Reactions
Topic: Balancing equations.
Replies: 35
Views: 737

### Re: Balancing equations.

When balancing chemical equations, I suggest starting off with the element that appear or occurs less times and then move your way to the next elements based off of that. It is important to remember that the coefficients have to be the lowest whole number, so double check. Also, it is okay to multip...
Sun Oct 11, 2020 1:28 am
Forum: Significant Figures
Topic: When should I start looking at sig figs?
Replies: 31
Views: 234

### When should I start looking at sig figs?

Whenever I'm solving a question, how do I know I can start looking at Sig figs. In other words, can I do it during my scratch work when I'm trying to figure out the final answer or do I use all numbers and decimals until I get to the final answer and then I use Sig Figs?
Thu Oct 08, 2020 10:12 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical and Molecular Formula
Replies: 17
Views: 124

### Re: Empirical and Molecular Formula

Hi Caro.
The empirical formula and the molecular formula can indeed be the same. Sometimes the ratio of atoms cannot be simplified further, so there will not be a multiple of said formula.

Go to advanced search