Search found 85 matches

by Lauren Mungo 1K
Sun Feb 21, 2021 9:22 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Meaning of K
Replies: 40
Views: 79

Re: Meaning of K

Yes in all equations K is the equilibrium constant. The only other thing you could confuse it with is K for kelvin so just make sure to read the problem carefully !
by Lauren Mungo 1K
Sun Feb 21, 2021 9:19 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gas Constant R
Replies: 41
Views: 65

Re: Gas Constant R

No you have to use the R values that corresponds to the units given in the problem
by Lauren Mungo 1K
Sun Feb 21, 2021 9:17 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: entropy positive value
Replies: 29
Views: 57

Re: entropy positive value

The entropy of the universe is always increasing and therefore is always positive
by Lauren Mungo 1K
Sun Feb 21, 2021 9:16 pm
Forum: Administrative Questions and Class Announcements
Topic: Final
Replies: 34
Views: 96

Re: Final

I think going over the textbook and sapling problems is a great way to start and then make sure you go through your lecture notes and textbook notes and maybe make a study guide of the material to help answer the conceptual based questions!
by Lauren Mungo 1K
Sun Feb 21, 2021 9:12 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Which R value to choose
Replies: 8
Views: 20

Re: Which R value to choose

It is always best to look at the units of the problem because you are going to need to pick the R value that corresponds with the units!
by Lauren Mungo 1K
Sun Feb 14, 2021 10:43 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Which R to use
Replies: 26
Views: 62

Re: Which R to use

you use 8.314J * K-1*mol-1 because if you look at the units, mol and K will then cancel so it leaves you with J
by Lauren Mungo 1K
Sun Feb 14, 2021 10:38 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Is it necessary to memorize Cp,m or Cv,m values? [ENDORSED]
Replies: 26
Views: 109

Re: Is it necessary to memorize Cp,m or Cv,m values? [ENDORSED]

No any specific values will be either given to us or on our equation sheet
by Lauren Mungo 1K
Sun Feb 14, 2021 10:35 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Sapling #7
Replies: 3
Views: 21

Re: Sapling #7

delta s is found by dividing the enthalpy by the boiling point.
by Lauren Mungo 1K
Sun Feb 14, 2021 10:33 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: temperature
Replies: 32
Views: 82

Re: temperature

Most of the time yes, but it depends on the problem. Some problems give you items such as heat capacity in degrees celsius so you have to check before you assume kelvin.
by Lauren Mungo 1K
Sun Feb 14, 2021 10:30 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Determining the Sign of S
Replies: 8
Views: 29

Re: Determining the Sign of S

You can find the sign by using the equation for delta S but also you can think about it in terms of how many states are available from one phase to the next
by Lauren Mungo 1K
Sun Feb 07, 2021 10:54 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Entropy
Replies: 27
Views: 83

Re: Entropy

entropy is a measure of disorder in the system and it is an extensive property as it is dependent on the about of particles present. The equation is s=KblnW1W2
by Lauren Mungo 1K
Sun Feb 07, 2021 10:44 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Extensive vs Intensive
Replies: 10
Views: 45

Re: Extensive vs Intensive

an extensive property depends on how much substance you have while intensive properties do not depend on the amount of substance present. Entropy and heat capacity are extensive properties and specific heat is an intensive property.
by Lauren Mungo 1K
Sun Feb 07, 2021 10:33 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: R constants
Replies: 40
Views: 880

Re: R constants

You just have to look at the units and pick the value of R that will cancel them out.
by Lauren Mungo 1K
Sun Feb 07, 2021 10:32 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hess's Law
Replies: 12
Views: 29

Re: Hess's Law

In regards to flipping an equation, you will first be able to tell when there is an equation that has a final product on the side of the reactants or vice versa. Then you know you have to flip it in order to get the substance on the correct side. Another way to know when to flip is if you need to sw...
by Lauren Mungo 1K
Sun Feb 07, 2021 10:08 pm
Forum: Phase Changes & Related Calculations
Topic: Endothermic v. Exothermic
Replies: 103
Views: 316

Re: Endothermic v. Exothermic

Yes exothermic reaction always have a negative delta H and endothermic reactions have a positive delta H
by Lauren Mungo 1K
Sun Jan 31, 2021 9:35 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Making X negligible
Replies: 34
Views: 97

Re: Making X negligible

If K is less than 10^-4 then you can consider it negligible, or if % ionization is less than 5%.
by Lauren Mungo 1K
Sun Jan 31, 2021 9:30 pm
Forum: Calculating Work of Expansion
Topic: Extensive vs Intensive
Replies: 4
Views: 318

Re: Extensive vs Intensive

Extensive properties are those such as heat capacity which are dependant on the amount of substance that you are working with, and intensive properties, such as specific heat capacity, are independent on quantities of substance.
by Lauren Mungo 1K
Thu Jan 28, 2021 10:20 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Equilibrium and stability of molecules
Replies: 4
Views: 31

Re: Equilibrium and stability of molecules

Yes, smaller equilibrium constants indicate that the reactants are more stable and larger equilibrium constants indicate that products are more stable. This is seen through the formula of K= [products]/[reactants] the larger the concentration of reactants, the smaller the value k, and the larger the...
by Lauren Mungo 1K
Thu Jan 28, 2021 10:15 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Changing Concentrations
Replies: 5
Views: 35

Re: Changing Concentrations

It depends on the Q value with respect to k. If Q>K then the the reaction is going to proceed towards the reactants, so the reactants would be +x and the products with be -x. If Q<K, then the reaction is going toward the products, so the reactions would be -x and the products would be +x.
by Lauren Mungo 1K
Thu Jan 28, 2021 10:05 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Outline Point: Effect of K
Replies: 5
Views: 28

Re: Outline Point: Effect of K

The k for the reverse reaction is 1/k1 and if you multiply a reaction by any coefficient then you raise k to that number. So if you multiply the system by 2 k would be k1^2
by Lauren Mungo 1K
Sun Jan 24, 2021 10:38 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Qudratic Formula
Replies: 19
Views: 108

Re: Qudratic Formula

I would suggest writing out every step to avoid error if you do not use a program to calculate your answer. Making sure all the number are correct starting from the ICE table all the way through is a good way to check your work.
by Lauren Mungo 1K
Sun Jan 24, 2021 10:33 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat released/ gained
Replies: 22
Views: 185

Re: Heat released/ gained

Forming a bond releases energy and breaking a bond requires energy
by Lauren Mungo 1K
Sun Jan 24, 2021 10:31 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hess's Law
Replies: 58
Views: 180

Re: Hess's Law

It states that the overall reaction enthalpy can be found by adding all the reaction enthalpies of intermediate steps, since enthalpy is a state function
by Lauren Mungo 1K
Sun Jan 24, 2021 10:25 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Neutral Solution
Replies: 9
Views: 59

Re: Neutral Solution

In neutral water, [H30+]=1.0x10^-7 and this is also the concentration of OH-. Together this gives us Kw= 1.0x10^-14 which can be useful in calculations.
by Lauren Mungo 1K
Sun Jan 24, 2021 10:06 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Exothermic rxns and heat
Replies: 9
Views: 156

Re: Exothermic rxns and heat

Q would be negative as exothermic indicates heat entering the surrounding area
by Lauren Mungo 1K
Sun Jan 17, 2021 10:03 pm
Forum: Ideal Gases
Topic: Kp?
Replies: 30
Views: 114

Re: Kp?

yes, partial pressure applies to gases while molar concentrations applies to aqueous compounds
by Lauren Mungo 1K
Sun Jan 17, 2021 10:01 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterms
Replies: 24
Views: 68

Re: Midterms

I believe we will take them during lecture time on the fridays of weeks 4 and 7 but we will be proctored by our TA
by Lauren Mungo 1K
Sun Jan 17, 2021 9:59 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: q vs k
Replies: 62
Views: 210

Re: q vs k

Q is the concentrations at some point before equilibrium is reached and K is at equilibrium.
by Lauren Mungo 1K
Sun Jan 17, 2021 9:56 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE table troubles
Replies: 16
Views: 84

Re: ICE table troubles

I noticed that it is easiest to write every step out. Once I have my ICE table set up and I have plugged the values into the equation for the equilibrium constant, I am careful to write every step of the quadratic equation and intermediate steps out. Then I double check my values when I start pluggi...
by Lauren Mungo 1K
Sun Jan 17, 2021 9:52 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: how to get molarity
Replies: 8
Views: 44

Re: how to get molarity

Molarity is moles present divided by liters. This problem gives you the molarity so you just have to plug the values into the equation for Q.
by Lauren Mungo 1K
Sun Jan 10, 2021 6:25 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Response of Equilibria to Change
Replies: 8
Views: 27

Re: Response of Equilibria to Change

Yes temperature is the only thing we have discussed that would result in a change in K. Everything else, such as changing concentration, would just result in a shifting in the direction of a reaction, and change when equilibrium would be reached.
by Lauren Mungo 1K
Sun Jan 10, 2021 6:17 pm
Forum: Ideal Gases
Topic: PV=nRT and concentration
Replies: 27
Views: 131

Re: PV=nRT and concentration

The definition of molarity is moles per liter. n represents moles and v is the volume which is expressed in liters. So by dividing n/V you get moles/liter which is molarity.
by Lauren Mungo 1K
Sun Jan 10, 2021 6:11 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Calculating Equilibrium Concentrations
Replies: 10
Views: 72

Re: Calculating Equilibrium Concentrations

Yes this is correct. This is because solids and solvents do not change in concentration very much.
by Lauren Mungo 1K
Sun Jan 10, 2021 6:07 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Left vs. Right
Replies: 29
Views: 125

Re: Left vs. Right

They both mean the same thing. They just signify which direction a reaction is proceeding, favors the left meaning reactants --> products and favors the right meaning products --> reactants
by Lauren Mungo 1K
Sun Jan 10, 2021 6:04 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K vs Kc
Replies: 9
Views: 55

Re: K vs Kc

Kc is just K that uses concentration as opposed to Kp which uses pressure!
by Lauren Mungo 1K
Sat Dec 12, 2020 8:43 pm
Forum: Hybridization
Topic: Electron Density
Replies: 6
Views: 65

Re: Electron Density

You should also count the lone pairs as they count as regions of electron density.
by Lauren Mungo 1K
Sat Dec 12, 2020 8:38 pm
Forum: Naming
Topic: Textbook Question 9C.1
Replies: 5
Views: 51

Re: Textbook Question 9C.1

You want to name the ligands first by alphabetical order. You have a water with the name aqua, then you have 5 CN-, which is cyano- with the prefix penta, and then you have your metal cobalt and since the compound has an overall negative charge you have to add -ate to the end, and its oxidation numb...
by Lauren Mungo 1K
Sat Dec 12, 2020 8:26 pm
Forum: DeBroglie Equation
Topic: p
Replies: 19
Views: 173

Re: p

p stands for momentum and can be used in the de broglie wave length equation and heisenberg's uncertainty principle.
by Lauren Mungo 1K
Sat Dec 12, 2020 8:18 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent/Angular Bond Angles
Replies: 5
Views: 56

Re: Bent/Angular Bond Angles

Yes this is correct.
by Lauren Mungo 1K
Sat Dec 12, 2020 8:16 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: HBrO2 vs HClO2
Replies: 7
Views: 85

Re: HBrO2 vs HClO2

Hi! In HBr, HBr is a stronger acid because it is larger and thus has a weaker bond to H. However, in HBrO2 and HClO2, the electronegativity of Cl, which is higher than Br, pulls the electrons towards it, thus weakening the OH bond, making it a stronger acid.
by Lauren Mungo 1K
Sun Dec 06, 2020 8:53 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: How to find coordination number.
Replies: 10
Views: 64

Re: How to find coordination number.

The coordination number is the number of bonds to the central atom. Therefore you have to count the bonds, but be careful for polydentate molecules.
by Lauren Mungo 1K
Sun Dec 06, 2020 8:52 pm
Forum: Naming
Topic: "(en)" Sapling
Replies: 19
Views: 139

Re: "(en)" Sapling

(en) is ethylenediamine and is a bidentate ligand
by Lauren Mungo 1K
Sun Dec 06, 2020 8:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sapling Week 9 HW #5
Replies: 5
Views: 43

Re: Sapling Week 9 HW #5

The coordination number is the number of bonds to the central atom. en is bidentate so that means it would bond twice with the central atom. Therefore, the coordination number should be six.
by Lauren Mungo 1K
Sun Dec 06, 2020 8:46 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Question about Shape
Replies: 5
Views: 41

Re: Question about Shape

Yes! They both have the same geometry because of the way the lone pairs interact with the bonds
by Lauren Mungo 1K
Sun Dec 06, 2020 8:42 pm
Forum: Sigma & Pi Bonds
Topic: Pi bonds
Replies: 7
Views: 53

Re: Pi bonds

I think Dr. Lavelle just wants us to be able to identify the characteristics of each bond (pi= side by side, one nodal plane, inhibits rotation)
by Lauren Mungo 1K
Sun Nov 29, 2020 10:06 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: #13 Sapling Week 8
Replies: 18
Views: 107

Re: #13 Sapling Week 8

It should be tetrahedral because there are four bond atoms to the central atom.
by Lauren Mungo 1K
Sun Nov 29, 2020 10:04 pm
Forum: Significant Figures
Topic: 40. versus 40
Replies: 23
Views: 190

Re: 40. versus 40

Yes. This is because anything to the left of a decimal point is counted as a sig fig while trailing zeros, with no decimals, are not considered significant
by Lauren Mungo 1K
Sun Nov 29, 2020 9:56 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Resonance Structures and Molecular Shape
Replies: 3
Views: 19

Re: Resonance Structures and Molecular Shape

No they will all not necessarily have the same shape. I would assume that you would be asked for the shape of the most stable resonance structure.
by Lauren Mungo 1K
Sun Nov 29, 2020 9:53 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: How do bonds affect shapes?
Replies: 11
Views: 90

Re: How do bonds affect shapes?

for determining the shape of a molecule, you are looking at regions of electron density. So even if there is a double or triple bond it would still be counted as one region of electron density. However, lone pairs also count as regions of electron density and have different effects on the shape so t...
by Lauren Mungo 1K
Sun Nov 29, 2020 9:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sapling HW #12
Replies: 5
Views: 45

Re: Sapling HW #12

first use the mass percentages to find the empirical formula. Then find the molecular formula using the molar mass given. From there you can draw the structure.
by Lauren Mungo 1K
Sun Nov 22, 2020 9:58 pm
Forum: Resonance Structures
Topic: Resonance Structures and Energy
Replies: 21
Views: 127

Re: Resonance Structures and Energy

Yes, the structure with the lowest energy will be the most stable so it will be favorable
by Lauren Mungo 1K
Sun Nov 22, 2020 9:57 pm
Forum: Lewis Structures
Topic: Central Atom Question
Replies: 20
Views: 159

Re: Central Atom Question

H can never be the central atom as it is only able to make one bond
by Lauren Mungo 1K
Sun Nov 22, 2020 9:54 pm
Forum: Lewis Structures
Topic: Lewis acids and bases
Replies: 23
Views: 128

Re: Lewis acids and bases

A lewis acid accepts electrons while a lewis base donates electrons
by Lauren Mungo 1K
Sun Nov 22, 2020 9:51 pm
Forum: Trends in The Periodic Table
Topic: Ion Trends
Replies: 18
Views: 128

Re: Ion Trends

Radius increases down a group and decreases across a period. Ionization energy and electron affinity increases across a period and decreases down a group. Anions have a greater radius and cations have a smaller radius.
by Lauren Mungo 1K
Sun Nov 22, 2020 9:48 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pair E-
Replies: 47
Views: 305

Re: Lone Pair E-

yes, they are considered to have their own region of electron density and contribute to the shape
by Lauren Mungo 1K
Sun Nov 15, 2020 9:18 pm
Forum: Lewis Structures
Topic: Sapling 9
Replies: 8
Views: 76

Re: Sapling 9

The structure with the lowest amount of formal charges is going to be the most stable and in reference to the bond lengths in this question they give you the overall average bond length and the bond lengths of single and double bonds so you can infer from the average which structure would be best or...
by Lauren Mungo 1K
Sun Nov 15, 2020 9:10 pm
Forum: Resonance Structures
Topic: Sapling Resonance Structure Question
Replies: 3
Views: 20

Re: Sapling Resonance Structure Question

The equation for formal charges is valence electrons subtracted from shared/bonded electrons divided by 2 plus lone pairs or V - (s/2 + L).
by Lauren Mungo 1K
Sun Nov 15, 2020 9:07 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Plausible Formal Charges
Replies: 6
Views: 34

Re: Plausible Formal Charges

Yes! Or if the overall formal charge of structure being zero is not possible, the structure with the lowest formal charge is the most stable.
by Lauren Mungo 1K
Sun Nov 15, 2020 9:05 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Sapling #9 week 5/6
Replies: 13
Views: 101

Re: Sapling #9 week 5/6

The lowest formal charge requires less energy and is more stable for the molecule therefore the molecule with the least charges on its components will be the most likely structure.
by Lauren Mungo 1K
Sun Nov 15, 2020 9:02 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Lewis acids and bases
Replies: 22
Views: 133

Re: Lewis acids and bases

Hi! Lewis acids accept an electron pair and lewis bases donate an electron pair. So molecules that have a positive charge are more likely to be lewis acids and molecules with a negative charge are more likely to be lewis bases.
by Lauren Mungo 1K
Sun Nov 08, 2020 8:13 pm
Forum: Resonance Structures
Topic: Formal charge on different resonance structures
Replies: 3
Views: 16

Re: Formal charge on different resonance structures

The structure that has a formal charge of 0 is the most stable structure. However, in most resonance structures what we are drawing is just a representation of the bond lengths and in reality the bond lengths are actually a blend of the single/double/triple bonds. So if there are multiple structures...
by Lauren Mungo 1K
Sun Nov 08, 2020 8:07 pm
Forum: Lewis Acids & Bases
Topic: Acid vs. Base
Replies: 8
Views: 66

Re: Acid vs. Base

We have only talked about lewis acids and lewis bases we have not started our unit on the general concepts of acids and base. So for now that is all you need to know about lewis acids and bases!
by Lauren Mungo 1K
Sun Nov 08, 2020 8:05 pm
Forum: Ionic & Covalent Bonds
Topic: Comparing Two Elements' Electronegativities
Replies: 3
Views: 21

Re: Comparing Two Elements' Electronegativities

In lecture, Dr. Lavelle said we would need to perform experiments to see whether or not the characteristics of the bond act more like that of a covalent bond or that of an iconic bond.
by Lauren Mungo 1K
Sun Nov 08, 2020 7:55 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm Solutions
Replies: 4
Views: 42

Re: Midterm Solutions

I don't think we will be able to see them but I think Lavelle said a lot of them were based off of homework problems maybe going over those would help!
by Lauren Mungo 1K
Sun Nov 08, 2020 7:52 pm
Forum: Lewis Structures
Topic: Lewis Acids/Bases
Replies: 4
Views: 17

Re: Lewis Acids/Bases

A lewis base donates an electron and a lewis acid accepts an electron!
by Lauren Mungo 1K
Sun Nov 01, 2020 7:00 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Textbook Exercise 1E.15
Replies: 6
Views: 46

Re: Textbook Exercise 1E.15

Whenever you are in doubt, just count the amount of electrons represented and match it to the element on the periodic table with the same number of electrons.
by Lauren Mungo 1K
Sun Nov 01, 2020 6:52 pm
Forum: Quantum Numbers and The H-Atom
Topic: 4th quantum number
Replies: 8
Views: 45

Re: 4th quantum number

The 4th quantum number just shows that any two paired electrons will be in different spin states, +1/2 or -1/2 and no two electrons in an atom have the same 4 quantum numbers
by Lauren Mungo 1K
Sun Nov 01, 2020 5:24 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Sapling HW Q17
Replies: 18
Views: 149

Re: Sapling HW Q17

To answer this question you have to know the trends of the periodic table. Atomic radii increases down a group because electrons are further from the nucleus. Atomic radii decreases across a period because increasing nuclear charge pulls them in closer.
by Lauren Mungo 1K
Sun Nov 01, 2020 5:19 pm
Forum: Trends in The Periodic Table
Topic: ionic radius
Replies: 14
Views: 69

Re: ionic radius

Cation are smaller than the original atom because there is less electron-electron repulsion. Anions are larger than their original atom for the opposite reason, there is more repulsion.
by Lauren Mungo 1K
Sun Nov 01, 2020 5:13 pm
Forum: Quantum Numbers and The H-Atom
Topic: Magnetic Quantum Number (orientation)
Replies: 2
Views: 31

Re: Magnetic Quantum Number (orientation)

This is because we know l=2 and ml is equal to the values between -l and l. So we know it would take the values of 2 to -2. So for the p orbital l=1 so ml= -1, 0, 1
by Lauren Mungo 1K
Sat Oct 24, 2020 10:01 pm
Forum: Properties of Light
Topic: Sapling problem
Replies: 6
Views: 109

Re: Sapling problem

For this one I just assumed it would go down to n=1 since they did not specify which means there would be 5 spectral lines. Then I calculated the wavelength for the n=6 to n=1 transition and the n=6 to n=5 transition to find the range. Hope this helps!
by Lauren Mungo 1K
Sat Oct 24, 2020 9:57 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Electron Transition Series
Replies: 2
Views: 44

Re: Electron Transition Series

I am not completely sure if they would ask it like that but I think it is important to know that Lyman series starts at n=1 and uses UV light and then the Balmer series starts at n=2 and uses visible light.
by Lauren Mungo 1K
Sat Oct 24, 2020 9:54 pm
Forum: Properties of Electrons
Topic: Atomic Spectra Module #42
Replies: 4
Views: 19

Re: Atomic Spectra Module #42

Hi! You should be able to use that equation. You have v= R(1/n^2-1/16) then you would have v/R= 1/n^2=1/16 then v/r +1/16= 1/n^2 then n^2= 1/(v/r-1/16) and then just take the square root! You could also find the wavelength to see what series it is which would tell you which level it started at. I ho...
by Lauren Mungo 1K
Sat Oct 24, 2020 9:45 pm
Forum: Balancing Chemical Reactions
Topic: L.39 Fundamental Question
Replies: 3
Views: 59

Re: L.39 Fundamental Question

Yes, that is what I used to find the empirical equation for the problem.
by Lauren Mungo 1K
Sat Oct 24, 2020 9:22 pm
Forum: Administrative Questions and Class Announcements
Topic: Constants in the tests
Replies: 5
Views: 47

Re: Constants in the tests

There is a constants sheet on the class website. This is what we will be given on our exams so I believe if we will need to convert to different units, the numbers will be given on the sheet.
by Lauren Mungo 1K
Sun Oct 18, 2020 2:35 pm
Forum: Properties of Electrons
Topic: Balmer/Lyman/Paschen Series
Replies: 2
Views: 30

Re: Balmer/Lyman/Paschen Series

The different series refer to which energy level the electrons transition between. So for the Lyman series which represents UV light, the electrons can travel all the way down to n=1 or the ground state level. However for the Balmer series which represents visible light, the lowest level the electro...
by Lauren Mungo 1K
Sun Oct 18, 2020 2:30 pm
Forum: Properties of Light
Topic: Equation masterlist
Replies: 6
Views: 78

Re: Equation masterlist

Hi. Yes there is. On the chem 14a website, on the left side there is a link that says constants and equations which gives you a document of the ones we will need this quarter.
by Lauren Mungo 1K
Sun Oct 18, 2020 2:27 pm
Forum: Student Social/Study Group
Topic: studying for exams
Replies: 21
Views: 320

Re: studying for exams

Hi! I have been doing textbook problems and am going to try to go to a few office hours and peer learning sessions this week to make sure I understand everything. We do not need to memorize equations. There is an equations and constants sheet that we will be able to use on the exams.
by Lauren Mungo 1K
Sun Oct 18, 2020 2:24 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation vs. Other Equation
Replies: 2
Views: 18

Re: Rydberg Equation vs. Other Equation

Hi. Yes you can use either, depending on the problem. However using the empirical equation of E=-hR/n^2 gives you a better conceptual idea of what is happening when an electron is moving from various levels. Both will give you the correct answer though.
by Lauren Mungo 1K
Wed Oct 14, 2020 10:39 pm
Forum: Properties of Light
Topic: Excited state of an electron
Replies: 4
Views: 32

Re: Excited state of an electron

Hi! This is because we are now discussing discussing quantum mechanics. These values are quantized meaning they are not continuous. There are only specific conditions/values that can be used. Therefore n can only be equal to 1,2,3,4..etc. It is not continuous meaning there are no circumstances in wh...
by Lauren Mungo 1K
Thu Oct 08, 2020 4:46 pm
Forum: Empirical & Molecular Formulas
Topic: difference between empirical and molecular
Replies: 15
Views: 70

Re: difference between empirical and molecular

Hi! You would have to know what the molar masses are of the molecular formula and empirical formula. The empirical formula will normally have a smaller molar mass as it just represents the ratio of molecules. If the two formulas are equal to each other, then their molar masses will be the same.
by Lauren Mungo 1K
Thu Oct 08, 2020 3:31 pm
Forum: SI Units, Unit Conversions
Topic: Sig figs and molar mass
Replies: 18
Views: 127

Re: Sig figs and molar mass

Hi! From what I have heard, you should use the amount of decimals given on the periodic table (there is one on the class website) and then round to significant figures at the end of the problem in order to give a more accurate answer.
by Lauren Mungo 1K
Thu Oct 08, 2020 1:55 pm
Forum: Significant Figures
Topic: Sapling HW #4
Replies: 31
Views: 341

Re: Sapling HW #4

Hi! 950000 only has two sig figs because it has two non zero digits and the rest are trailing zeros which are not significant unless there is a decimal present (i.e. 500.) 80060 has four sig figs because it has two non zeros digits with zeros in the middle and zeros between other numbers are signifi...
by Lauren Mungo 1K
Wed Oct 07, 2020 8:36 pm
Forum: Balancing Chemical Reactions
Topic: Fundamental Exercise H7
Replies: 5
Views: 55

Re: Fundamental Exercise H7

Hi! The catalyst only affects the rate of the reaction. Since it is neither a reactant nor product, you do not need to include it in the equation (although I believe it can be written above the yield arrow to show it has been used).
by Lauren Mungo 1K
Wed Oct 07, 2020 11:06 am
Forum: Molarity, Solutions, Dilutions
Topic: G. 23
Replies: 5
Views: 59

Re: G. 23

Hi! What I did first was convert the grams of NaCl and KCl to moles. Then from there, I calculated the amount of moles of Cl that are present in both amounts of KCl and NaCl by using the molar ratios. For example, for 1 mole of Na there is 1 mole of Cl ( so they should equal the same as the amount o...

Go to advanced search