Search found 83 matches

by Maya Pakulski 1D
Tue Feb 11, 2020 8:23 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Using Cp vs just R or C for ΔS
Replies: 2
Views: 26

Re: Using Cp vs just R or C for ΔS

Which equation to use is dependent on which information you were given in the problem or which information could be solved for and then plugged into another equation. You really have to combine equations and move things around to fit what info you were given.
by Maya Pakulski 1D
Tue Feb 11, 2020 8:13 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Extra Practice
Replies: 4
Views: 34

Re: Extra Practice

You also can google examples of these problems are there are probably tons that will come up from other teachers or classes.
by Maya Pakulski 1D
Tue Feb 11, 2020 8:11 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: U(total)=(3/2)nrt
Replies: 2
Views: 19

Re: U(total)=(3/2)nrt

705087773 wrote:using 3/2R is for if there is constant volume in the process

5/2R is for constant pressure, correct?
by Maya Pakulski 1D
Mon Feb 10, 2020 4:05 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 4J.7
Replies: 2
Views: 19

Re: 4J.7

Make sure also when looking at the values for delta H and delta S you take into account that one is given in J and the other in KJ so you will have to convert one or the other.
by Maya Pakulski 1D
Mon Feb 10, 2020 4:03 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Spontaneous Reactions
Replies: 2
Views: 7

Re: Spontaneous Reactions

You look at the value for deltaG. If deltaG is negative it is spontaneous and if it is positive it is not spontaneous. Similarly there was a question about whether a compound would be stable or unstable based on its deltaG value and if the value is negative the compound is stable, is the value is po...
by Maya Pakulski 1D
Tue Feb 04, 2020 3:03 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reversible/Irreversible Reactions
Replies: 6
Views: 22

Re: Reversible/Irreversible Reactions

On a test question would it always specify that the reaction is happening irreversibly or reversibly?
by Maya Pakulski 1D
Tue Feb 04, 2020 2:54 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: molar entropy
Replies: 2
Views: 13

Re: molar entropy

Here's a website that has some rules on how to tell which molecule will have the higher molar entropy! https://opentextbc.ca/introductorychemi ... changes-2/
by Maya Pakulski 1D
Tue Feb 04, 2020 2:52 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: overall definitions
Replies: 4
Views: 33

Re: overall definitions

This is so helpful thank you!
by Maya Pakulski 1D
Tue Feb 04, 2020 2:46 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: HW 4F.9
Replies: 2
Views: 20

Re: HW 4F.9

I had this same question because when I first tried to solve it I calculated each volume using PV=nRT and then substituted them into the nRln(V2/V1) equation, however I got the wrong answer because I didn't realize we can just plug the inverse of the pressures right into the equation instead of usin...
by Maya Pakulski 1D
Tue Feb 04, 2020 2:41 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Microstates
Replies: 5
Views: 19

Re: Microstates

When calculating for the micro states what number do we raise to the n?
by Maya Pakulski 1D
Fri Jan 31, 2020 7:04 pm
Forum: Phase Changes & Related Calculations
Topic: Phase Changes
Replies: 17
Views: 43

Re: Phase Changes

Yes, the temperature stays constant while the energy continues to increase.
by Maya Pakulski 1D
Fri Jan 31, 2020 7:02 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: qp and qv
Replies: 8
Views: 37

Re: qp and qv

This is because by definition delta H only equals q at constant pressure.
by Maya Pakulski 1D
Wed Jan 29, 2020 1:37 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Homework for Week 4
Replies: 2
Views: 22

Re: Homework for Week 4

Yes, every week you just pick 5 that go with whichever outline we are on in class. You could do all 5 problems from 4A if you wanted or do some from A, some from C and some from D.
by Maya Pakulski 1D
Wed Jan 29, 2020 1:35 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: temperature
Replies: 4
Views: 8

Re: temperature

It depends on what the problem gives you. Just make sure for any given problem that you use the units that match the constant you're given.
by Maya Pakulski 1D
Tue Jan 28, 2020 11:20 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Units
Replies: 5
Views: 17

Units

Unless specified by the problem would it matter on a test whether our answers are in J or KJ?
by Maya Pakulski 1D
Thu Jan 23, 2020 5:18 pm
Forum: Phase Changes & Related Calculations
Topic: Autoprotolysis
Replies: 15
Views: 80

Re: Autoprotolysis

Emily Lo 1J wrote:It is the transfer of a proton between the same type of molecule. An example of it would be 2H2O H3O + OH

What are some other common examples of autoprotolysis besides water?
by Maya Pakulski 1D
Thu Jan 23, 2020 5:14 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Heat Capacity Intensive or Extensive?
Replies: 4
Views: 211

Re: Heat Capacity Intensive or Extensive?

MariahClark 2F wrote:I don't know about your reasoning, but heat capacity is extensive. It changes when it becomes specific heat capacity, as that is intensive instead.


What is the difference between intensive and extensive in general?
by Maya Pakulski 1D
Thu Jan 23, 2020 5:13 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: state property
Replies: 5
Views: 20

Re: state property

What are others examples of things that could be state properties?
by Maya Pakulski 1D
Thu Jan 23, 2020 5:11 pm
Forum: Phase Changes & Related Calculations
Topic: Thermochemistry homework problems
Replies: 2
Views: 20

Re: Thermochemistry homework problems

Do problems from chapter 4 as that is the chapter we are starting. If we start a new topic halfway through the week it normally doesn't matter which section you do problems from as long as they were covered recently.
by Maya Pakulski 1D
Thu Jan 23, 2020 5:05 pm
Forum: Phase Changes & Related Calculations
Topic: Internal Energy Change
Replies: 3
Views: 23

Re: Internal Energy Change

The internal energy change is the value of the potential energy plus the kinetic energy. We use this to tell whether energy is coming into or out of the system in the form of heat or work. The equation is deltaU=q+w where w is work and q is heat.
by Maya Pakulski 1D
Wed Jan 15, 2020 8:54 pm
Forum: Ideal Gases
Topic: ICE tables
Replies: 9
Views: 47

Re: ICE tables

If the questions asks for just K, and not Kc or Kp, then you need to look at the equation. If the reactants and products are gases then you should use Kp, because it is implied. If the reactants and products of the equation are aqueous then you should use Kc because it is implied. However if it ask...
by Maya Pakulski 1D
Wed Jan 15, 2020 8:41 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Compression on Equilibrium
Replies: 4
Views: 13

Re: Compression on Equilibrium

Neither would be favored because you have the same number of moles on either side.
by Maya Pakulski 1D
Wed Jan 15, 2020 8:38 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7826
Views: 1085620

Re: Post All Chemistry Jokes Here

Why can you never trust atoms?


Because they make everything up.
by Maya Pakulski 1D
Wed Jan 15, 2020 8:34 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: When to use K and Kp
Replies: 12
Views: 36

Re: When to use K and Kp

Kallista McCarty 1C wrote:
Kristina Rizo 2K wrote:I thought Kp was used for gas only? Can someone clarify this please.

Kp is used for gases to determine partial pressures! Kc is used for concentrations and Ka and Kb are for acids and bases.


This might be a dumb question but you calculate all of these the same way right, with products/reactants?
by Maya Pakulski 1D
Wed Jan 15, 2020 8:19 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Water in Acid-Base Equilibria
Replies: 3
Views: 12

Re: Water in Acid-Base Equilibria

Liquids and pure solids are never included in equilibrium calculations.
by Maya Pakulski 1D
Wed Jan 15, 2020 8:05 pm
Forum: Administrative Questions and Class Announcements
Topic: Study Guide Test One
Replies: 17
Views: 86

Re: Study Guide Test One

Some of the UA's also give out review sheets during their Peer Learning sessions.
by Maya Pakulski 1D
Thu Jan 09, 2020 5:05 pm
Forum: Ideal Gases
Topic: K based on phases
Replies: 4
Views: 19

Re: K based on phases

You will never include the concentrations of solids and liquids because, for example, when a solid is dissolved in water the concentration changes such a small amount that it is almost insignificant unlike with a gas where the concentration does change.
by Maya Pakulski 1D
Thu Jan 09, 2020 8:34 am
Forum: Ideal Gases
Topic: Understanding Q
Replies: 19
Views: 70

Re: Understanding Q

Yes, you would still omit solids and pure liquids. You also emit these when making an ICE table.
by Maya Pakulski 1D
Wed Jan 08, 2020 2:30 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Homework 5J.1c
Replies: 3
Views: 30

Re: Homework 5J.1c

If you add something to either the products or reactant side the reaction will shift to the opposite side and if you take a product or reactant away the reaction shifts to the side you took it from. In this case it would shift to the right, as you took away a reactant, and the amount of H2 would inc...
by Maya Pakulski 1D
Wed Jan 08, 2020 2:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Partial Pressure vs. Concentration
Replies: 4
Views: 18

Re: Partial Pressure vs. Concentration

Kp can only be used for gases because only gases can exert pressure on a container. Therefore, if you only have aqueous solutions in your chemical equation, then you know you must calculate for Kc since there are no gases. If you have only gases in your chemical equation, you can solve for either K...
by Maya Pakulski 1D
Wed Jan 08, 2020 2:23 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Textbook question 5I.3
Replies: 2
Views: 28

Re: Textbook question 5I.3

I need this as well. I keep getting a different answer too.
by Maya Pakulski 1D
Fri Dec 06, 2019 10:05 am
Forum: Administrative Questions and Class Announcements
Topic: Final exam
Replies: 17
Views: 177

Re: Final exam

ShastaB4C wrote:Does anyone know approximately how many questions the final exam will be?

On the page about final locations and review sessions it says there will be 8 questions on the final.
by Maya Pakulski 1D
Fri Dec 06, 2019 10:04 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Sig Figs in 6B3
Replies: 3
Views: 27

Re: Sig Figs in 6B3

When looking at pH and pOH there are different significant figure rules, here's a website that explains what they are. http://abacus.bates.edu/acad/depts/biobook/How-SigF.pdf
by Maya Pakulski 1D
Thu Dec 05, 2019 2:45 pm
Forum: Air Pollution & Acid Rain
Topic: reactions of acid rain
Replies: 1
Views: 45

Re: reactions of acid rain

The chemical equations that produce acid rain are done in a few parts. In regards to nitric acid the first equation that takes place is N2 +O2 =2NO, then the second equation is 2NO + O2 = 2NO2. The last equation that happens is 3NO2 + 3H2O = (2H3O+) + (2NO3-) + NO. Sulfuric acid is formed in three d...
by Maya Pakulski 1D
Mon Dec 02, 2019 9:33 am
Forum: Hybridization
Topic: 2F.5
Replies: 4
Views: 27

Re: 2F.5

Here's a good video that goes through types of hybridization with lots of examples!
https://www.youtube.com/watch?v=otYj92d7rB0
by Maya Pakulski 1D
Mon Dec 02, 2019 9:31 am
Forum: Amphoteric Compounds
Topic: Memorizing Amphoteric Oxides
Replies: 2
Views: 20

Re: Memorizing Amphoteric Oxides

My TA said the same thing which is they will most likely give us the obvious ones that follow the pattern of the diagonal band, which you can find charts of online, instead of the ones on the edge that aren't as obvious.
by Maya Pakulski 1D
Sat Nov 30, 2019 2:32 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: [H3O+] and [OH-]
Replies: 3
Views: 38

[H3O+] and [OH-]

How do you convert between [H3O+] and [OH-] such as in problem 6B.9?
by Maya Pakulski 1D
Fri Nov 29, 2019 11:21 am
Forum: Lewis Acids & Bases
Topic: Weak and Strong Acids and Bases
Replies: 3
Views: 15

Re: Weak and Strong Acids and Bases

Mt TA told us some tips which are that inorganic acids are typically strong acids and organic acids are typically weak. To tell the inorganic from the organic, the inorganic normally have the H at the front ( ex. HCl, H2SO4, HClO3) while the organic have the H at the end (ex. CH3COOH, CH3CH(OH)).
by Maya Pakulski 1D
Mon Nov 25, 2019 1:54 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: acids
Replies: 4
Views: 25

Re: acids

Midori Hupfeld 3D wrote:Do acids always have a hydrogen ion in them?

Yes, acids always have hydrogen as acids form hydrogen when they disassociate in water.
by Maya Pakulski 1D
Mon Nov 25, 2019 1:50 pm
Forum: Bronsted Acids & Bases
Topic: 6A.5
Replies: 1
Views: 20

6A.5

How would you determine which compound is an acid and a base in the equation on question 6A.5?
by Maya Pakulski 1D
Mon Nov 25, 2019 1:47 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: coordination number
Replies: 2
Views: 33

Re: coordination number

Here's a website that explains all the shapes based on the coordination number and tells a little about each. https://chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Supplemental_Modules_(Inorganic_Chemistry)/Coordination_Chemistry/Structure_and_Nomenclature_of_Coordination_Compounds/Coordinatio...
by Maya Pakulski 1D
Mon Nov 25, 2019 1:44 pm
Forum: Amphoteric Compounds
Topic: Amphiprotic
Replies: 11
Views: 75

Re: Amphiprotic

Is there a way to tell if something is amphiprotic?
by Maya Pakulski 1D
Mon Nov 25, 2019 1:41 pm
Forum: Lewis Acids & Bases
Topic: When is an acid considered Bronsted?
Replies: 9
Views: 59

Re: When is an acid considered Bronsted?

Why are there there two definitions for acids and bases? Why not just one?
by Maya Pakulski 1D
Sat Nov 23, 2019 11:48 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Where is this chapter in the textbook
Replies: 1
Views: 28

Re: Where is this chapter in the textbook

In 9C there is mention of them and there is a table with all the common ligands, the chapter isn't specifically about ligands however.
by Maya Pakulski 1D
Sat Nov 23, 2019 11:45 am
Forum: Naming
Topic: Negative charge with Coordination Compound
Replies: 3
Views: 23

Re: Negative charge with Coordination Compound

If it is positively charged do we add anything to the end like we do when its negative?
by Maya Pakulski 1D
Fri Nov 22, 2019 2:53 pm
Forum: Naming
Topic: Naming
Replies: 6
Views: 55

Re: Naming

How many of the common ligands do we need to know? Just the ones on the chart on page 724 of the textbook or are there more we need to know as well?
by Maya Pakulski 1D
Fri Nov 22, 2019 2:48 pm
Forum: Naming
Topic: 9C.7
Replies: 1
Views: 16

9C.7

In 9C.7 the question asks "Which of the following isomers of diaminobenzene can form chelating complexes" and then gives three example. How would you go about answering this question?
by Maya Pakulski 1D
Sat Nov 16, 2019 1:38 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 9
Views: 48

Re: Bond Angles

So we basically just have to memorize which bond angles go with which shapes?
by Maya Pakulski 1D
Fri Nov 15, 2019 1:53 pm
Forum: Sigma & Pi Bonds
Topic: Sigma & Pi Bonds
Replies: 5
Views: 52

Re: Sigma & Pi Bonds

Pi bonds are also more commonly found in double and triple bonds, while they are not included in single bonds. Pi bonds add bond strength to the bonds - hence why double and triple bonds are stronger than single bonds. All types of bonds have sigma bonds. So basically most first bonds are sigma bon...
by Maya Pakulski 1D
Thu Nov 14, 2019 2:39 pm
Forum: Dipole Moments
Topic: Strength of Interactions
Replies: 4
Views: 33

Re: Strength of Interactions

The order of inter molecular forces from strongest to weakest are ion-ion, ion-dipole, hydrogen bonds, dipole-dipole, and dipole induced- dipole.
by Maya Pakulski 1D
Mon Nov 11, 2019 12:58 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 and Melting Points
Replies: 7
Views: 36

Re: Boiling and Melting Points

The stronger the intermolecular forces the higher the boiling point/melting point will be. Generally, polar molecules have dipole-dipole forces, making them have stronger intermolecular forces than nonpolar molecules, thus, they will boil/melt at a higher temperature. How do we find these intermole...
by Maya Pakulski 1D
Mon Nov 11, 2019 12:49 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: difference between intermolecular forces
Replies: 3
Views: 18

Re: difference between intermolecular forces

Are N, O and F the only atoms that will be involved with hydrogen bonds. Say you had a molecule without one of these could it form a hydrogen bond?
by Maya Pakulski 1D
Sat Nov 09, 2019 2:32 pm
Forum: Bond Lengths & Energies
Topic: Midterm
Replies: 9
Views: 101

Re: Midterm

Dr. Lavelle said we will get them back on Wednesday during lecture.
by Maya Pakulski 1D
Sat Nov 09, 2019 2:31 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarisability vs Polarizing Power
Replies: 15
Views: 110

Re: Polarisability vs Polarizing Power

Is there a trend on the periodic table that tells polarisability and polarizing power or we just have to know based on the size of the cation?
by Maya Pakulski 1D
Sat Nov 09, 2019 2:28 pm
Forum: SI Units, Unit Conversions
Topic: Memorizing Conversions
Replies: 23
Views: 223

Re: Memorizing Conversions

Most of the conversions will be given but some of them you might have to memorize. A sample sheet of the constants, equations, and conversions we are given for tests is on Dr. Lavelle's website.
by Maya Pakulski 1D
Mon Nov 04, 2019 9:27 am
Forum: Trends in The Periodic Table
Topic: Electronegativity
Replies: 7
Views: 73

Re: Electronegativity

Most likely we will just need to know that electronegativity increases up a a group and to the right across a period.
by Maya Pakulski 1D
Sun Nov 03, 2019 8:01 am
Forum: Dipole Moments
Topic: Midterm
Replies: 8
Views: 92

Re: Midterm

On the topic of the midterm, will we need to know content up to Mondays lecture or last Fridays lecture?
by Maya Pakulski 1D
Wed Oct 30, 2019 9:28 am
Forum: Lewis Structures
Topic: Formal charge
Replies: 9
Views: 65

Re: Formal charge

Can someone explain how to find the lone pair electrons when trying to find the formal charge? When finding lone pair electrons you just count the pairs of electrons that are not bonded to another element. For example in the Lewis structure for water, the O has two bonds and two lone pairs because ...
by Maya Pakulski 1D
Tue Oct 29, 2019 4:52 pm
Forum: Bond Lengths & Energies
Topic: Bond lengths
Replies: 15
Views: 141

Re: Bond lengths

Are bond lengths different for each molecule or are they always the same length?
by Maya Pakulski 1D
Tue Oct 29, 2019 4:45 pm
Forum: Resonance Structures
Topic: Bond Order
Replies: 2
Views: 21

Re: Bond Order

Here's a really good website that explains it! Basically you just divide the number of bonds by the number of bond groups within a certain compound. https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Chem...
by Maya Pakulski 1D
Tue Oct 29, 2019 4:40 pm
Forum: Ionic & Covalent Bonds
Topic: 4f, 5f Electron Configurations
Replies: 2
Views: 17

Re: 4f, 5f Electron Configurations

you could think about it as f-d-s-p i guess. for ex, if you wanted the electron configuration for gold (Au), you would write it as [Xe]4f^14 5d^10 6s^1. you would do the same thing for 5f too On the exceptions like Cr and Cu where we take an electron away from the s orbital and put it in the d orbi...
by Maya Pakulski 1D
Mon Oct 28, 2019 2:06 pm
Forum: Ionic & Covalent Bonds
Topic: Number of Chemistry Community Posts
Replies: 3
Views: 48

Re: Number of Chemistry Community Posts

As on last night you should have posted 20 times I think because we just finished week 4.
by Maya Pakulski 1D
Mon Oct 21, 2019 9:29 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: How to use it
Replies: 5
Views: 47

Re: How to use it

zoedfinch1K wrote:In addition to Brianna Becerra 1F, you would typically use this equation when being asked for the minimum uncertainty in speed/velocity when given the physical constraints or vice versa.

Is minimum uncertainty something different or when we solve this equation we get minimum uncertainty?
by Maya Pakulski 1D
Mon Oct 21, 2019 9:25 am
Forum: *Shrodinger Equation
Topic: Review
Replies: 4
Views: 49

Re: Review

If you go to one of the peer learning sessions and ask they will go over it and do practice problems.
by Maya Pakulski 1D
Mon Oct 21, 2019 9:20 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Filling the 4s and 3d blocks
Replies: 3
Views: 23

Re: Filling the 4s and 3d blocks

In a cases like this we write the d block before the s block right? I've seen example where the electron configurations are written either way so I wasn't sure if we are supposed to do it a certain way.
by Maya Pakulski 1D
Mon Oct 21, 2019 9:16 am
Forum: Trends in The Periodic Table
Topic: 1F.6
Replies: 1
Views: 21

1F.6

For question 1F.6, we're asked to find the element in a given pair that has the smaller second ionization energy, how do you find the second ionization energy?
by Maya Pakulski 1D
Mon Oct 21, 2019 9:13 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Exceptions in Electron Configurations
Replies: 5
Views: 38

Re: Exceptions in Electron Configurations

Besides chromium and copper are there any other ones we should know?
by Maya Pakulski 1D
Mon Oct 14, 2019 9:33 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: HW question 1A.15
Replies: 2
Views: 44

Re: HW question 1A.15

We know that the ultraviolet region of hydrogen has an energy level of n=1. With 102.6 nm we can find the frequency using v=speed of light/wavelength 2.998*10^8 m.s^-1 / (102.6*10^-9 m) = 2.922*10^15 s^-1 We then use the Rydberg formula, so v=R((1/n1 ^2) - (1/n2 ^2)) 1/n2 ^2 = 1- ((2.922*10^15 s^-1...
by Maya Pakulski 1D
Mon Oct 14, 2019 9:28 am
Forum: Quantum Numbers and The H-Atom
Topic: Question 1D.17
Replies: 1
Views: 29

Question 1D.17

How would I start to answer this question? For each orbital listed in exercise 1D.15, give possible values of the magnetic quantum number.
by Maya Pakulski 1D
Mon Oct 14, 2019 9:23 am
Forum: Photoelectric Effect
Topic: Confusion on equations
Replies: 9
Views: 120

Re: Confusion on equations

Depending on what values you are given you also can rearrange each equation and combine them to find unknown variables. For instance if you were asked to solve for energy and you were only given wavelength not frequency, you can solve the equation lambda*v=c for v so that you can then plug your new ...
by Maya Pakulski 1D
Mon Oct 14, 2019 9:17 am
Forum: Photoelectric Effect
Topic: Threshold and activation energy
Replies: 3
Views: 33

Re: Threshold and activation energy

Threshold energy is the energy needed to make effective collisions while activation energy is the energy needed to make these collisions even occur. A molecule normally doesn't have enough threshold energy to make this occur so it needs activation energy to start these collisions.
by Maya Pakulski 1D
Mon Oct 14, 2019 9:13 am
Forum: Properties of Electrons
Topic: Photons
Replies: 9
Views: 77

Re: Photons

Yes, even if the photon has some energy, but not enough to get the electron the the next energy level, then the electron will not be ejected as it cannot go halfway between energy levels.
by Maya Pakulski 1D
Tue Oct 08, 2019 12:01 pm
Forum: Properties of Light
Topic: Question 1A.3 c
Replies: 5
Views: 81

Re: Question 1A.3 c

Can somebody explain to me why it isn't B?
by Maya Pakulski 1D
Tue Oct 08, 2019 11:56 am
Forum: Empirical & Molecular Formulas
Topic: Fundamental F.19
Replies: 3
Views: 39

Re: Fundamental F.19

If we hadn't been given the molar mass of the compound would there have been anyway to tell what the molecular formula was?
by Maya Pakulski 1D
Tue Oct 08, 2019 11:52 am
Forum: Balancing Chemical Reactions
Topic: How to write reactions for tests
Replies: 5
Views: 90

Re: How to write reactions for tests

My TA said we should write them, but I also heard from a UA that we probably won't need to, so maybe write them if you know them just to be safe.
by Maya Pakulski 1D
Tue Oct 08, 2019 11:49 am
Forum: Administrative Questions and Class Announcements
Topic: Week 2 Homework Problems [ENDORSED]
Replies: 67
Views: 1689

Re: Week 2 Homework Problems [ENDORSED]

Jaklin Astvatsatryan 3G wrote:
Lauren Sanchez 3D wrote:Just to make sure, the homework problems are now due during our actual discussions right?


Yes. Our TA's will be collecting them the day of your discussion.


Our answers on chemistry community will always be due Sunday night though right?
by Maya Pakulski 1D
Tue Oct 08, 2019 11:36 am
Forum: Properties of Light
Topic: Hw Question 1A.9
Replies: 5
Views: 57

Hw Question 1A.9

For the question 1A.9, how would you find the the wavelength and frequency that go along with the second line that says 3.3X10^-19J?
by Maya Pakulski 1D
Thu Oct 03, 2019 2:49 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Avogadro's Number
Replies: 8
Views: 131

Re: Avogadro's Number

Slide 5 of this power point ( https://www.slideshare.net/smartensen/mole-calculations) has a good diagram to show how to convert from atoms, moles, grams and liters!
by Maya Pakulski 1D
Thu Oct 03, 2019 2:37 pm
Forum: SI Units, Unit Conversions
Topic: Scientific Notation (general requirement for the course)
Replies: 5
Views: 44

Re: Scientific Notation (general requirement for the course)

I think we use scientific notation to write the answer with the correct number of significant figures. So if the answer was 12300 but the question only asks for 2 sig figs, we would write it as 1.2 x 10^4. If they do not specify which format we should use does it matter? Is there one that's better ...
by Maya Pakulski 1D
Wed Oct 02, 2019 5:42 pm
Forum: Limiting Reactant Calculations
Topic: Limiting Reactant Question
Replies: 4
Views: 28

Limiting Reactant Question

If on a hypothetical limiting reactant problem you found out that you need the exact same amount of each reactant for the reaction to occur, are both the reactants considered limiting or neither of them are and there just isn't a limiting reactant in this case?
by Maya Pakulski 1D
Wed Oct 02, 2019 5:33 pm
Forum: Limiting Reactant Calculations
Topic: HW Question M19
Replies: 2
Views: 39

HW Question M19

When starting question 19 "A stimulant in coffee and tea is caffeine, a substance of molar mass 194 g/mol. When 0.376 g of caffeine was burned, 0.682 g of carbon dioxide, 0.174 g of water, and 0.110 g of nitrogen were formed. Determine the empirical and molecular formulas of caffeine, and write...
by Maya Pakulski 1D
Wed Oct 02, 2019 5:30 pm
Forum: Molarity, Solutions, Dilutions
Topic: General Rounding Question
Replies: 9
Views: 67

Re: General Rounding Question

Throughout the problem is it safe to carry three decimal places through all your math and then round to sig figs at the end or should you go out another decimal place?

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