Search found 44 matches

by Madelyn Romberg 1H
Thu Jan 23, 2020 6:36 pm
Forum: Phase Changes & Related Calculations
Topic: Autoprotolysis
Replies: 15
Views: 78

Re: Autoprotolysis

Autoprotolysis is proton transfer between the same type of molecule. In this class, water was the example. 2H20 <-> h3o+ + oh-
by Madelyn Romberg 1H
Thu Jan 23, 2020 6:30 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Exothermic vs. Endothermic reactions
Replies: 12
Views: 37

Re: Exothermic vs. Endothermic reactions

From our current tools given, he will give the change in enthalpy and from that information you will have to determine if it is exo/endo, and he may ask questions that utilize Le Chateliers principle in regards to temp.
by Madelyn Romberg 1H
Thu Jan 23, 2020 6:26 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Prep for Test 1
Replies: 16
Views: 89

Re: Prep for Test 1

You need to know how to calculate and convert between the two, but memorizing values is unnecessary.
by Madelyn Romberg 1H
Thu Jan 23, 2020 6:25 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Temperature
Replies: 5
Views: 14

Re: Temperature

Temperature can be thought of as a reactant. If adding heat to a reaction, it will favor whichever direction has the positive change in H. This is because forming more of the "energy rich" molecule will harness more of the heat to minimize the net change of temperature of the environment. ...
by Madelyn Romberg 1H
Thu Jan 23, 2020 6:14 pm
Forum: Phase Changes & Related Calculations
Topic: Enthalpy Units
Replies: 3
Views: 11

Re: Enthalpy Units

It is the variations of energy units. The SI unit is Joules. However, calories/kilocalories are also common and you can convert between Joules and calories.
by Madelyn Romberg 1H
Thu Jan 16, 2020 10:31 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Quadratic
Replies: 6
Views: 25

Re: Quadratic

I would recommend becoming familiar with it in general though. It will help you timewise to know how to use the formula and not waste time on the math when you can be focusing more on the chemistry at hand.
by Madelyn Romberg 1H
Thu Jan 16, 2020 10:25 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: When to use K and Kp
Replies: 12
Views: 36

Re: When to use K and Kp

Typically it will specify. When given all gases, you will likely use partial pressure. If they specify concentration when given gasses, you may need to use PV=nRT to convert between the two. K is a general symbol which can apply to Kp or Kc. In this class he has had us specify which we are using.
by Madelyn Romberg 1H
Thu Jan 16, 2020 10:24 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Reaction shifts right or left?
Replies: 14
Views: 56

Re: Reaction shifts right or left?

Yes, this is correct. It is about looking at the concentrations in the Q value to see if the reaction will shift right or left.
by Madelyn Romberg 1H
Thu Jan 16, 2020 10:23 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Endothermic/Exothermic Rxns and Delta H
Replies: 3
Views: 21

Re: Endothermic/Exothermic Rxns and Delta H

The equation is extremely simplified and ignores all of the moments in which, yes, forming bonds did release energy. However, when thinking about it with common sense, it is an endothermic reaction. First, light (energy) is required for photosynthesis to happen. Secondly, our bodies use glucose as a...
by Madelyn Romberg 1H
Thu Jan 16, 2020 10:17 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Reaction Quotient
Replies: 11
Views: 27

Re: Reaction Quotient

They are measured the same. The key difference is K is ONLY at equilibrium where as Q is at any point in the reaction. Q can tell us which way the reaction will favor when compared to Q.
by Madelyn Romberg 1H
Sat Jan 11, 2020 3:22 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE Table Ratios
Replies: 7
Views: 33

Re: ICE Table Ratios

You would get the same answer but it is easier when using whole numbers to calculate--plus, it will then match your balanced equation.
by Madelyn Romberg 1H
Sat Jan 11, 2020 3:18 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Why does only Temp affect K?
Replies: 8
Views: 38

Re: Why does only Temp affect K?

Temperature can alter the stability of the molecules in the reaction. Hence, by changing the temperature, the products or reactants may become more/less stable at different temperatures. With this information, the reaction my shift to the left or right, altering our K.
by Madelyn Romberg 1H
Sat Jan 11, 2020 3:14 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K vs. Q
Replies: 10
Views: 46

Re: K vs. Q

K is an equilibrium constant that is most favorable to the reaction under certain conditions. Q measures where the reaction is at any given time in relationship to K.
by Madelyn Romberg 1H
Sat Jan 11, 2020 3:12 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Change in k
Replies: 11
Views: 40

Re: Change in k

K tells us the ratio of concentrations between products and reactants that is most favorable given the current conditions. So, with changing concentrations, you will be changing your Q. Then, the reaction will work to bring Q towards K. The total amount of product and reactant will change, but their...
by Madelyn Romberg 1H
Sat Jan 11, 2020 3:09 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Significant Figures
Replies: 8
Views: 36

Re: Significant Figures

It could be either. Sig figs are based off of the smallest number of sig figs initially measured.
by Madelyn Romberg 1H
Fri Dec 07, 2018 1:15 pm
Forum: Polyprotic Acids & Bases
Topic: oxacids and carboxylic acids
Replies: 5
Views: 394

Re: oxacids and carboxylic acids

Carboxylic acids are common of organic chemistry whereas oxacids will appear in general chemistry (with metals)
by Madelyn Romberg 1H
Fri Dec 07, 2018 1:10 pm
Forum: Lewis Acids & Bases
Topic: How to Identify Lewis acid and Bases
Replies: 4
Views: 197

Re: How to Identify Lewis acid and Bases

Also helpful is to remember Lewis Acids will accept lone pairs and Lewis Bases with donate lone pairs, hence your conclusion was correct
by Madelyn Romberg 1H
Fri Dec 07, 2018 1:08 pm
Forum: Conjugate Acids & Bases
Topic: Neutralization Reactions
Replies: 6
Views: 362

Re: Neutralization Reactions

Always remember water is a product, so there will be a cation paired with a hydroxyl and an anion paired with a H+ ion. So work backwards to fill in the missing pieces
by Madelyn Romberg 1H
Thu Nov 29, 2018 1:23 pm
Forum: Naming
Topic: Naming Coordination Compounds
Replies: 9
Views: 286

Re: Naming Coordination Compounds

I believe we will need to be able to remember them; he stated during lecture that we can find the common ligands in the textbook, which makes it seem like we should be familiar with them.
by Madelyn Romberg 1H
Thu Nov 29, 2018 1:21 pm
Forum: Biological Examples
Topic: cisplatin in stopping DNA replication
Replies: 3
Views: 109

Re: cisplatin in stopping DNA replication

An important key to remember is the CIS part of the molecule (as a TRANS version does exist). This allows both ligands to bind to the DNA and effectively start replication whereas the TRANS version is unable to do this.
by Madelyn Romberg 1H
Sat Nov 24, 2018 4:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone pairs determining shape?
Replies: 5
Views: 154

Re: Lone pairs determining shape?

There are two versions of a molecule that we use to identify shape. The molecular shape does NOT use lone pair electrons when determining shape; however, they play an influence in bond angles that can therefore slightly alter the molecular shape. The electronic geometry of a molecule does consider l...
by Madelyn Romberg 1H
Sat Nov 24, 2018 4:46 pm
Forum: Hybridization
Topic: Steps to figure out hybridization
Replies: 3
Views: 89

Re: Steps to figure out hybridization

When you draw the lewis structure, you will be able to identify how many bonding regions there are. Then, you just need to make sure the hybridization state has the same number of orbitals as bonding regions.
by Madelyn Romberg 1H
Thu Nov 15, 2018 12:00 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: Boiling point
Replies: 12
Views: 330

Re: Boiling point

A rod shaped molecule has stronger intermolecular forces, meaning they have a stronger attraction to each other. To break this stronger connection requires more energy, resulting in a higher boiling point. The opposite is true for the spherical shape.
by Madelyn Romberg 1H
Thu Nov 15, 2018 11:56 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular shape
Replies: 3
Views: 75

Re: Molecular shape

A good thing to think about are organic molecules (hydrocarbons, more specifically, alkanes). Van Der Waals forces are a strong contributor to the boiling point of molecules. Longer, more linear alkanes have a stronger Van Der Waals forces and therefore it requires more energy to break this attracti...
by Madelyn Romberg 1H
Thu Nov 15, 2018 11:46 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Thanksgiving [ENDORSED]
Replies: 14
Views: 374

Re: Thanksgiving [ENDORSED]

I would make plans for either option and he should tell us in the upcoming classes if it will be canceled
by Madelyn Romberg 1H
Thu Nov 08, 2018 2:09 pm
Forum: Bond Lengths & Energies
Topic: bond lengths and strengths
Replies: 9
Views: 208

Re: bond lengths and strengths

In a less scientific way, it is easier to break a thin stick that is about 6 feet long (a single bond) rather than a stick that is 3 centimeters long (a triple bond). Hence, single bonds are weaker than double or triple because they are longer.

Note, the chosen lengths are arbitrary.
by Madelyn Romberg 1H
Thu Nov 08, 2018 2:06 pm
Forum: Ionic & Covalent Bonds
Topic: Periodic Trends
Replies: 3
Views: 118

Re: Periodic Trends

When it comes to diagonal elements, it is generally difficult to [censored] their comparing electronegativity because you experience two opposing forces that influence electronegativity. In the case of sodium and calcium, sodium appears to have a higher electronegativity because it is in the period ...
by Madelyn Romberg 1H
Thu Nov 01, 2018 9:58 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal charge purpose
Replies: 40
Views: 1694

Re: Formal charge purpose

Calculating formal charges allows us to draw the most stable structure. For example, it will tell us if we should consider double bonds within the molecules to create more stability.
by Madelyn Romberg 1H
Thu Nov 01, 2018 9:48 pm
Forum: Resonance Structures
Topic: Electron movements
Replies: 2
Views: 80

Electron movements

How do the electrons move within atoms to create the "blended" characteristic?
by Madelyn Romberg 1H
Thu Nov 01, 2018 9:46 pm
Forum: Coordinate Covalent Bonds
Topic: Tetrafluoroborate anion
Replies: 3
Views: 357

Re: Tetrafluoroborate anion

Going off of this question, why does the boron trifluoride atom not form a coordinate covalent bond with the fluorine to get an octet opposed to adding an additional fluorine atom?
by Madelyn Romberg 1H
Thu Oct 25, 2018 11:40 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration Exceptions [ENDORSED]
Replies: 3
Views: 130

Electron Configuration Exceptions [ENDORSED]

Why do elements such as copper not follow our expected electron configurations
by Madelyn Romberg 1H
Thu Oct 25, 2018 11:38 pm
Forum: Einstein Equation
Topic: Units
Replies: 6
Views: 396

Units

Are remembering units for this equation, and others, necessary? Or are they given on the test?
by Madelyn Romberg 1H
Thu Oct 25, 2018 11:36 pm
Forum: Quantum Numbers and The H-Atom
Topic: Vocabulary confusion
Replies: 2
Views: 282

Vocabulary confusion

What is the difference between principal quantum number and magnetic quantum number?
by Madelyn Romberg 1H
Thu Oct 25, 2018 11:36 pm
Forum: Quantum Numbers and The H-Atom
Topic: Vocabulary confusion
Replies: 2
Views: 167

Vocabulary confusion

What is the difference between principal quantum number and magnetic quantum number?
by Madelyn Romberg 1H
Thu Oct 18, 2018 7:59 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Representation
Replies: 4
Views: 186

Representation

What does the numerical value given by the uncertainty principle actually mean?
by Madelyn Romberg 1H
Thu Oct 18, 2018 7:55 pm
Forum: *Shrodinger Equation
Topic: Shrodinger equation
Replies: 2
Views: 112

Shrodinger equation

What is the relationship between energy and the shrodinger equation? I do not understand the "operate a change on" part of the notes.
by Madelyn Romberg 1H
Thu Oct 18, 2018 7:45 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Nodal Planes
Replies: 1
Views: 87

Nodal Planes

Can someone explain the concept of nodal planes and their relationship to orbital shapes.
by Madelyn Romberg 1H
Thu Oct 11, 2018 4:20 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect
Replies: 4
Views: 81

Re: Photoelectric Effect

The scientists expected that increasing the intensity of the light would eject electrons from a metals surface (which did not happen). The scientists then had to change their thought process. Instead of increasing the intensity, they increased the frequency, which ejected electrons. This data reflec...
by Madelyn Romberg 1H
Thu Oct 11, 2018 4:08 pm
Forum: Photoelectric Effect
Topic: Electrons
Replies: 2
Views: 57

Electrons

How do we detect the electrons whose velocity is zero when the threshold energy and energy of the photon are equal?
by Madelyn Romberg 1H
Thu Oct 11, 2018 4:03 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra
Replies: 1
Views: 35

Atomic Spectra

Question: Why does hydrogen emits multiple wavelengths to create its own "fingerprint", yet it only has one electron whose energy level could change can emit the frequencies?
by Madelyn Romberg 1H
Sun Oct 07, 2018 6:29 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molarity Formula [ENDORSED]
Replies: 1
Views: 64

Molarity Formula [ENDORSED]

Can someone confirm the typical notation used for molarity? To clarify, which variables represent what?
by Madelyn Romberg 1H
Sun Oct 07, 2018 6:28 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Avogadro's Constant Definition
Replies: 7
Views: 455

Avogadro's Constant Definition

When it comes to di/tri/etc molecules, does Avogadro's constant apply? Or is it atom and not number of particles?
by Madelyn Romberg 1H
Sun Oct 07, 2018 6:24 pm
Forum: Significant Figures
Topic: Sig Fig in Relation to Zero
Replies: 3
Views: 151

Sig Fig in Relation to Zero

0 can be a sig fig but I am confused when it comes to decimals. For example, which zeros are sig figs in 0.0490?

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