Search found 97 matches

by Jacob Puchalski 1G
Sun Mar 08, 2020 7:56 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: galvanic vs electrolytic
Replies: 12
Views: 84

galvanic vs electrolytic

What's the difference between galvanic and electrolytic cells?
by Jacob Puchalski 1G
Sun Mar 08, 2020 7:54 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: The Third Law
Replies: 3
Views: 78

Re: The Third Law

The third law of thermodynamics is basically as the temperature reaches absolute zero (0 Kelvin) then entropy will also decrease to zero.
by Jacob Puchalski 1G
Sun Mar 08, 2020 7:27 pm
Forum: First Order Reactions
Topic: Graphing 1st order reaction rates
Replies: 6
Views: 45

Graphing 1st order reaction rates

Why do we graph ln[A] against time instead of just [A] against time?
by Jacob Puchalski 1G
Sun Mar 08, 2020 7:14 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Slow step
Replies: 2
Views: 34

Re: Slow step

I'd think that if they propose certain mechanisms then one of them would have to match the given rate law?
by Jacob Puchalski 1G
Sun Mar 08, 2020 7:08 pm
Forum: Zero Order Reactions
Topic: examples of zero order reactions?
Replies: 6
Views: 52

examples of zero order reactions?

What's an example of a zero order reaction? I still don't completely understand how they would work
by Jacob Puchalski 1G
Sun Mar 01, 2020 9:15 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: initial reaction rates
Replies: 2
Views: 54

Re: initial reaction rates

We work with initial reaction rates because they're more clear and easier to measure.
by Jacob Puchalski 1G
Sun Mar 01, 2020 9:13 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Kinetics vs. thermodynamics
Replies: 4
Views: 57

Re: Kinetics vs. thermodynamics

Thermodynamics tells us whether the forward or reverse process is favored. Kinetics touches more on the energy during the reaction itself.
by Jacob Puchalski 1G
Sun Mar 01, 2020 9:09 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: kinetically stable?
Replies: 10
Views: 124

Re: kinetically stable?

Basically the activation energy (the hump part of the graph) is high enough so that under normal conditions the reaction won't proceed.
by Jacob Puchalski 1G
Sun Mar 01, 2020 9:08 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: order of reactions
Replies: 7
Views: 102

Re: order of reactions

it tells you how the concentration of the reactants affects the rate.
by Jacob Puchalski 1G
Sun Mar 01, 2020 9:06 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: first order
Replies: 8
Views: 106

Re: first order

It has a linear rate
by Jacob Puchalski 1G
Sun Feb 23, 2020 1:46 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Galvanic cell vs battery system
Replies: 3
Views: 42

Re: Galvanic cell vs battery system

I think a galvanic cell just has a negative Gibbs free energy value.
by Jacob Puchalski 1G
Sun Feb 23, 2020 1:42 pm
Forum: Balancing Redox Reactions
Topic: Acidic vs Basic
Replies: 4
Views: 52

Re: Acidic vs Basic

If they occur in basic solutions, the steps are the same, except for when you balance one side with H+ you need to balance both sides with the same amount of OH-, so that there is H20 on one side and OH- on the other side.
by Jacob Puchalski 1G
Sun Feb 23, 2020 1:36 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Notation of Species
Replies: 3
Views: 26

Re: Notation of Species

You use a single line to differentiate between phases. If they're both in the same phase then you list them using a comma.
by Jacob Puchalski 1G
Sat Feb 22, 2020 9:57 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Writing half-rxn
Replies: 3
Views: 41

Re: Writing half-rxn

I think we might be provided with half reactions but also it would be good to practice coming up with them on our own?
by Jacob Puchalski 1G
Sat Feb 22, 2020 9:28 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 5G.15
Replies: 3
Views: 47

Re: 5G.15

I also keep getting the same as you so it might be an error
by Jacob Puchalski 1G
Sun Feb 16, 2020 11:19 pm
Forum: Balancing Redox Reactions
Topic: Whats the difference between oxidizing agent and oxiadation
Replies: 6
Views: 87

Re: Whats the difference between oxidizing agent and oxiadation

Oxidation is the transfer of electrons in a reaction; the oxidizing agent is the reactant that is reduced.
by Jacob Puchalski 1G
Sun Feb 16, 2020 11:10 pm
Forum: Balancing Redox Reactions
Topic: How do you combine half reactions together?
Replies: 2
Views: 19

Re: How do you combine half reactions together?

If a reactant in one reaction is the same as a product in the other then you can cancel them both. For example if 5O2 is a reactant in the first and 3O2 is a product in the second then you can subtract the difference so that in the final reaction there is 2O2 on the reactant side.
by Jacob Puchalski 1G
Sun Feb 16, 2020 11:06 pm
Forum: Van't Hoff Equation
Topic: Significance of Van't Hoff Equation
Replies: 8
Views: 106

Re: Significance of Van't Hoff Equation

I think the point was to relate K to the temperature? I might be wrong
by Jacob Puchalski 1G
Sun Feb 16, 2020 11:05 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: standard entropies vs. entropies
Replies: 5
Views: 119

Re: standard entropies vs. entropies

The standard entropy of a reaction is found in lab conditions.
by Jacob Puchalski 1G
Sun Feb 16, 2020 11:02 pm
Forum: Balancing Redox Reactions
Topic: Why do we split equations?
Replies: 12
Views: 112

Re: Why do we split equations?

It's just easier to understand what's happening; you don't really need to if you don't want to.
by Jacob Puchalski 1G
Mon Feb 10, 2020 2:15 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 4A13
Replies: 1
Views: 31

Re: 4A13

I'm pretty sure the heat released is measured by the calorimeter as the surroundings rather than the system. So since it's exothermic, Q is negative and heat is released into the surroundings, raising the temperature.
by Jacob Puchalski 1G
Mon Feb 10, 2020 2:00 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 4.17E
Replies: 1
Views: 32

Re: 4.17E

Since they give you the specific amount of moles then you're able to find the specific reaction enthalpy.
by Jacob Puchalski 1G
Mon Feb 10, 2020 1:49 am
Forum: Phase Changes & Related Calculations
Topic: 4.5
Replies: 1
Views: 24

Re: 4.5

It's mentioned that the ice took 10.5 (10 hours and 30 minutes) hours to reach 5.00 degrees. If it takes 30 minutes for water to increase five degrees in temperature, it's safe to say that the ice took ten hours to melt, and as water also took thirty minutes to reach 5.00 degrees.
by Jacob Puchalski 1G
Mon Feb 10, 2020 1:37 am
Forum: Administrative Questions and Class Announcements
Topic: Midterm Conversion
Replies: 3
Views: 46

Re: Midterm Conversion

I'm sure that if that's something we need on the test then they'll provide it
by Jacob Puchalski 1G
Thu Jan 30, 2020 7:04 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Homework question 4B.13
Replies: 2
Views: 41

Re: Homework question 4B.13

Pretty sure the manual's solution is correct. Did you use w=-nRTln(V2/V1)? Or maybe make sure you're using the right units?
by Jacob Puchalski 1G
Thu Jan 30, 2020 5:46 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Solids and Liquids not in K
Replies: 1
Views: 31

Re: Solids and Liquids not in K

With gas you can compress or expand the volume which changes the concentration, and with aqueous solutions the concentration of dissolved molecules can also increase or decrease. However, for the most part it's extremely difficult for the concentration of solids and liquids to change so it remains c...
by Jacob Puchalski 1G
Thu Jan 30, 2020 5:39 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Closed and Isolated
Replies: 5
Views: 44

Re: Closed and Isolated

I'm pretty sure there's technically no such thing as a completely isolated system. However, some experimental systems are close enough to be considered isolated since the changes are negligible.
by Jacob Puchalski 1G
Thu Jan 30, 2020 5:36 pm
Forum: Calculating the pH of Salt Solutions
Topic: Textbook problem 6b.3
Replies: 1
Views: 68

Re: Textbook problem 6b.3

I think what the question is saying is that the technician meant to produce 200 ml of a .025M HCl solution, but since he accidentally used a 250mL flask he added 50mL more water than he meant to. So he didn't actually produce a .025M HCl solution. If he made it right you would just find -log(.025) =...
by Jacob Puchalski 1G
Thu Jan 30, 2020 5:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Test #1// #6
Replies: 2
Views: 42

Re: Test #1// #6

To find Ka, you find the concentration of the products and divide that by the concentration of the reactants. They gave you .10 M for the initial concentration of HF. pH is -log[H3O+] = 2.63, so [H3O+] = 2.34 x 10^-3. Since one mole of HF dissociates into one mole of H30+ and one mole of F-, you kno...
by Jacob Puchalski 1G
Sun Jan 26, 2020 7:47 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Weak acid/base
Replies: 14
Views: 158

Re: Weak acid/base

If the acid or base isn't completely dissociated then it's probably weak.
by Jacob Puchalski 1G
Sun Jan 26, 2020 7:43 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: H2O as a Gas
Replies: 12
Views: 181

Re: H2O as a Gas

Yeah you'd include it if it was a gas.
by Jacob Puchalski 1G
Sun Jan 26, 2020 7:39 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Predicting Molar Heat Capacity
Replies: 3
Views: 52

Re: Predicting Molar Heat Capacity

I think that in general the more complex a molecule is the higher the capacity will be, because more energy would go into the bonds. So I think NO2 would have a higher capacity?
by Jacob Puchalski 1G
Sun Jan 26, 2020 7:32 pm
Forum: Ideal Gases
Topic: Determining N
Replies: 9
Views: 111

Re: Determining N

It's the ideal gas law so you just use it for gases.
by Jacob Puchalski 1G
Sat Jan 25, 2020 3:34 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: bomb calorimeter
Replies: 5
Views: 39

Re: bomb calorimeter

It measures the heat of chemical reactions
by Jacob Puchalski 1G
Sun Jan 19, 2020 3:59 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6B.11B
Replies: 2
Views: 46

Re: 6B.11B

For part a, since M is moles per liter, the [OH-] of the original solution would be 100 times stronger, since the 5.0 mL solution was diluted to 500 mL. So the original [OH-] would be 18M. For part b, you use the equation you have to convert the 18M OH- to grams of Na2O. 18 mol/L x .2 L x 1 mol Na2O...
by Jacob Puchalski 1G
Sun Jan 19, 2020 3:34 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6D.13
Replies: 1
Views: 20

Re: 6D.13

a) pH = 5.00
b) pH = 5.63
c) pH = 2.72
d) pH = 8.97
by Jacob Puchalski 1G
Sun Jan 19, 2020 12:21 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6D.3 part B
Replies: 1
Views: 21

Re: 6D.3 part B

So ultimately we're trying to get from pH to pKb. Since propylamine is a base we know it's best to deal in terms of OH-, so we should convert the pH to pOH (2.14). Since pOH is just -log[OH-], we can find [OH-] through 10^-2.14, which comes out to be 7.2 x 10^-3. We know that Kb is the molarity of t...
by Jacob Puchalski 1G
Sat Jan 18, 2020 11:55 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6D13 part d
Replies: 2
Views: 33

Re: 6D13 part d

So I think you might have tried to find the concentration of H30+ by setting up the equation x^2/.2 = Ka? I don't think that would work out because the reactant is a base? If you wanted to find and use the concentration of H30+, you would need to first find the concentration of OH- by using Kb. Once...
by Jacob Puchalski 1G
Sat Jan 18, 2020 11:16 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6D7
Replies: 1
Views: 36

Re: 6D7

I'm pretty sure it's just a typo, and should just be in the denominator. If you carry out the problem as normal without the typo, you get the same answer it provides.
by Jacob Puchalski 1G
Sun Jan 12, 2020 9:25 pm
Forum: General Science Questions
Topic: Proton and Electron attraction
Replies: 5
Views: 58

Re: Proton and Electron attraction

Opposite charges attract!
by Jacob Puchalski 1G
Sun Jan 12, 2020 8:29 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Reaction Quotient
Replies: 11
Views: 81

Re: Reaction Quotient

The reaction quotient is the proportion of the molarity of the products to the reactants at any given time of the reaction. It's pretty much the same as Kc and Kp but those two are measured specifically at equilibrium.
by Jacob Puchalski 1G
Sun Jan 12, 2020 8:24 pm
Forum: Ideal Gases
Topic: PV=nRT
Replies: 3
Views: 18

Re: PV=nRT

R is a constant used in the ideal gas law, 8.314 J/(K.mol)
by Jacob Puchalski 1G
Sun Jan 12, 2020 5:29 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Units and Conversions of Kp
Replies: 3
Views: 35

Re: Units and Conversions of Kp

Not sure which is the default but 1 bar = 10^5 Pa (1 kilopascal is 1,000 pascals).
by Jacob Puchalski 1G
Sun Jan 12, 2020 5:26 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: the "quick way"
Replies: 4
Views: 46

Re: the "quick way"

I think what you're talking about is whether the reaction shifts left or right? If the volume decreases and more moles of gas are added to the reactants, then the reaction shifts right. If the volume decreases and more moles of gas are added to the products, then the reaction shifts left.
by Jacob Puchalski 1G
Sat Dec 07, 2019 2:16 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Carbonato
Replies: 1
Views: 46

Re: Carbonato

Yeah I think it could be bidentate
by Jacob Puchalski 1G
Sat Dec 07, 2019 2:14 pm
Forum: Lewis Acids & Bases
Topic: Water
Replies: 7
Views: 157

Re: Water

Water can act as an acid in the presence of a base, and can act as a base in the presence of an acid.
by Jacob Puchalski 1G
Sat Dec 07, 2019 1:58 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 6B.1
Replies: 1
Views: 34

Re: 6B.1

The pH scale is a log scale, so if you reduce the molar concentration to .1, or 10% of the original concentration then the resulting pH will raise by 1; -Log(.1) = 1. So if molarity of HCl is reduced to 12% of the original concentration, then -log(.12) = .92. So all you need to know is the differenc...
by Jacob Puchalski 1G
Sat Dec 07, 2019 1:35 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: chelating vs. polydentate?
Replies: 2
Views: 74

Re: chelating vs. polydentate?

I think it's just that polydentate ligands happen to form a chelate with the central atom.
by Jacob Puchalski 1G
Sat Dec 07, 2019 1:32 pm
Forum: Hybridization
Topic: double and triple bonds
Replies: 6
Views: 211

Re: double and triple bonds

I'm pretty sure the pi bonds in double and triple bonds aren't hybridized.
by Jacob Puchalski 1G
Sat Dec 07, 2019 1:24 pm
Forum: Ionic & Covalent Bonds
Topic: Hydrogen bonds
Replies: 4
Views: 122

Hydrogen bonds

For a dipole bond to be considered a hydrogen bond, does the hydrogen atom have to be both bonded to a N, O, or F atom within the same molecule, and then form the hydrogen bond itself with a N, O, or F atom with a lone pair in another molecule?
by Jacob Puchalski 1G
Sun Dec 01, 2019 7:31 pm
Forum: Dipole Moments
Topic: dipole moments
Replies: 6
Views: 143

Re: dipole moments

Yep. Nonpolar molecules could have dipole moments as well that happen to cancel each other out.
by Jacob Puchalski 1G
Sun Dec 01, 2019 7:28 pm
Forum: Naming
Topic: cis and trans
Replies: 1
Views: 24

Re: cis and trans

I would think so because they make kind of a big difference in many cases.
by Jacob Puchalski 1G
Sun Dec 01, 2019 7:27 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Weak vs. Strong Acids
Replies: 3
Views: 32

Weak vs. Strong Acids

At what point is an acid (or base) weak or solid? Where do you draw the line?
by Jacob Puchalski 1G
Sun Dec 01, 2019 7:21 pm
Forum: Hybridization
Topic: Order When Writing
Replies: 5
Views: 57

Re: Order When Writing

I think either would be fine since they're both correct.
by Jacob Puchalski 1G
Sun Dec 01, 2019 7:19 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Difference in Concentrations
Replies: 3
Views: 34

Re: Difference in Concentrations

Acids release H+ ions in water, while bases release OH- ions in water.
by Jacob Puchalski 1G
Fri Nov 22, 2019 2:42 pm
Forum: Naming
Topic: Prefixes
Replies: 4
Views: 75

Prefixes

In lecture today Dr. Lavelle mentioned something about the prefixes bis-, tris-, tetrakis-, and pentakis-... can someone explain what he was talking about?
by Jacob Puchalski 1G
Fri Nov 22, 2019 2:39 pm
Forum: Lewis Acids & Bases
Topic: Lewis & Bronsted
Replies: 3
Views: 56

Lewis & Bronsted

What's the difference between a Lewis and Bronsted acid and base?
by Jacob Puchalski 1G
Fri Nov 22, 2019 2:36 pm
Forum: Administrative Questions and Class Announcements
Topic: Week 9 Homework
Replies: 2
Views: 45

Re: Week 9 Homework

I think it depends on your TA but you could probably just turn it in the week after
by Jacob Puchalski 1G
Fri Nov 22, 2019 2:31 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Definition of a Ligand
Replies: 4
Views: 43

Re: Definition of a Ligand

I'm pretty sure it's just a molecule attached to a central metal ion.
by Jacob Puchalski 1G
Fri Nov 22, 2019 2:29 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Sphere
Replies: 6
Views: 63

Re: Coordination Sphere

It's the central metal atom and the ligands attached to it.
by Jacob Puchalski 1G
Fri Nov 15, 2019 5:22 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E.19 b
Replies: 1
Views: 20

Re: 2E.19 b

The Be atom is central, forming a 180 degree angle with the two bonded C atoms. But there are also three H atoms bonded to each C atom. Because of this there are four regions of e- density around the C atoms, so they are the center of a tetrahedral structure. The structure of the entire molecule is ...
by Jacob Puchalski 1G
Fri Nov 15, 2019 5:17 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E.17 B
Replies: 2
Views: 31

Re: 2E.17 B

I'm pretty sure there should be two lone pairs on each of the bonded nitrogen atoms while the central nitrogen has a formal charge of +1. The overall charge is still -1 and that way the angle would be 180.
by Jacob Puchalski 1G
Fri Nov 15, 2019 4:56 pm
Forum: Ionic & Covalent Bonds
Topic: Types of Covalent Bonds
Replies: 4
Views: 50

Types of Covalent Bonds

Which type of bond is strongest, between polar, non-polar, and coordinate covalent bonds?
by Jacob Puchalski 1G
Fri Nov 15, 2019 4:51 pm
Forum: Dipole Moments
Topic: Xenon
Replies: 4
Views: 70

Re: Xenon

I think he mentioned something about how since xenon has a low electronegativity, its electrons are more easily distorted by atoms with stronger electronegativity, like fluorine.
by Jacob Puchalski 1G
Fri Nov 15, 2019 4:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Formula Exceptions
Replies: 6
Views: 99

VSEPR Formula Exceptions

Are there ever any exceptions to the VSEPR formula? Or can we always rely on it?
by Jacob Puchalski 1G
Wed Nov 06, 2019 11:30 pm
Forum: SI Units, Unit Conversions
Topic: Kg
Replies: 4
Views: 180

Kg

Why is the SI unit of mass kg, not g?
by Jacob Puchalski 1G
Wed Nov 06, 2019 11:26 pm
Forum: Quantum Numbers and The H-Atom
Topic: Rydberg equation
Replies: 9
Views: 221

Re: Rydberg equation

Why is that preferred?
by Jacob Puchalski 1G
Wed Nov 06, 2019 9:25 pm
Forum: Dipole Moments
Topic: Ionic bonds
Replies: 5
Views: 59

Ionic bonds

Do ionic bonds ever have dipole moments?
by Jacob Puchalski 1G
Wed Nov 06, 2019 9:23 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Solving with velocity
Replies: 3
Views: 136

Solving with velocity

When given the velocity, is the actual velocity important at all or just the change of velocity?
by Jacob Puchalski 1G
Wed Nov 06, 2019 9:15 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: orbitals past f
Replies: 5
Views: 154

orbitals past f

When would we ever see l>3?
by Jacob Puchalski 1G
Wed Oct 30, 2019 4:23 pm
Forum: Octet Exceptions
Topic: expanded valence shells
Replies: 2
Views: 41

expanded valence shells

Are atoms with expanded valence shells stable?
by Jacob Puchalski 1G
Wed Oct 30, 2019 4:12 pm
Forum: Ionic & Covalent Bonds
Topic: Partial charge
Replies: 4
Views: 50

Partial charge

Are partial charges found only in covalent bonds or also in ionic bonds?
by Jacob Puchalski 1G
Wed Oct 30, 2019 3:56 pm
Forum: Ionic & Covalent Bonds
Topic: ionic vs covalent bonds
Replies: 6
Views: 82

ionic vs covalent bonds

So basically, whether a bond is ionic or covalent depends on the difference of the electronegativities of the atoms involved?
by Jacob Puchalski 1G
Wed Oct 30, 2019 3:40 pm
Forum: Ionic & Covalent Bonds
Topic: 2A 1c
Replies: 1
Views: 38

Re: 2A 1c

I asked my TA about the valence electrons of elements in the d-block, and the short answer was that any electrons in shells that aren't included in the noble gas notation would be considered valence electrons. So for Mn, after [Ar] there are seven electrons. Hope that helps
by Jacob Puchalski 1G
Wed Oct 30, 2019 3:33 pm
Forum: Electronegativity
Topic: Electronegativity trends
Replies: 5
Views: 59

Electronegativity trends

Are we expected to know specific values or just the general trends?
by Jacob Puchalski 1G
Wed Oct 23, 2019 6:25 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: General Terminology for Electron Configuration
Replies: 2
Views: 17

Re: General Terminology for Electron Configuration

I'm pretty sure the energy shell is the principle quantum number (n), the orbital is the angular momentum quantum number (l), and the subshell is the magnetic quantum number (ml).
by Jacob Puchalski 1G
Wed Oct 23, 2019 6:05 pm
Forum: Lewis Structures
Topic: Number of valence electrons
Replies: 3
Views: 49

Number of valence electrons

Is it ever possible to have more than 8 valence electrons?
by Jacob Puchalski 1G
Wed Oct 23, 2019 6:03 pm
Forum: Lewis Structures
Topic: Valence e in d block
Replies: 5
Views: 110

Re: Valence e in d block

So do most d-block elements have only a couple of valence electrons?
by Jacob Puchalski 1G
Wed Oct 23, 2019 5:50 pm
Forum: Lewis Structures
Topic: chemical formulas
Replies: 3
Views: 67

chemical formulas

Are we going to need to know the chemical formulas of compounds in order to create the lewis structure, or will they be given?
by Jacob Puchalski 1G
Wed Oct 23, 2019 2:58 pm
Forum: Ionic & Covalent Bonds
Topic: octet rule
Replies: 6
Views: 114

octet rule

Are there any exceptions to the octet rule besides H, He, Li, & Be?
by Jacob Puchalski 1G
Wed Oct 16, 2019 8:22 pm
Forum: Properties of Electrons
Topic: 1B.15
Replies: 4
Views: 65

Re: 1B.15

You can use De Broglie's equation : λ=h/p (p=mv).
by Jacob Puchalski 1G
Wed Oct 16, 2019 8:15 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbitals
Replies: 4
Views: 67

Re: Orbitals

That helps! What I don't understand is if it's arbitrary, why did Dr. Lavelle say in his lecture today that when n=2, l=1, and ml=-1, the e- is in the 2Px state?
by Jacob Puchalski 1G
Wed Oct 16, 2019 7:04 pm
Forum: Properties of Electrons
Topic: Question About Electron State
Replies: 3
Views: 50

Re: Question About Electron State

It means the electron is located in the p orbital of the second energy level, and is located somewhere along the x plane.
by Jacob Puchalski 1G
Wed Oct 16, 2019 6:58 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbitals
Replies: 4
Views: 67

Orbitals

How are we able to determine whether a p orbital is px, py, or pz?
by Jacob Puchalski 1G
Wed Oct 16, 2019 6:44 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Homework Problem Help
Replies: 5
Views: 84

Re: Homework Problem Help

For a, you know it's the second period and a p orbital. There's six elements in the second period with a p orbital, so there's six possible orbitals. That's how I'd go about each question.
by Jacob Puchalski 1G
Wed Oct 09, 2019 4:40 pm
Forum: Molarity, Solutions, Dilutions
Topic: Fundamentals G21 [ENDORSED]
Replies: 2
Views: 109

Re: Fundamentals G21 [ENDORSED]

Ashley explained it well, here's part a written out. .5 grams KCl x (1 mole KCl)/(74.55 g KCl) = .0067 moles of KCl. For every molecule of KCl, there is one K atom. So there are .0067 moles of K. .5 grams K2S x (1 mole K2S)/(110.27 g K2S) = .0045 moles of K2S For every molecule of K2S, there are two...
by Jacob Puchalski 1G
Wed Oct 09, 2019 4:01 pm
Forum: Properties of Electrons
Topic: Energy
Replies: 6
Views: 86

Re: Energy

Yep, electrons will only move up an energy level if that specific requirement is met. That's why there's distinct spectral lines on an atomic spectrum.
by Jacob Puchalski 1G
Wed Oct 09, 2019 3:38 pm
Forum: Properties of Electrons
Topic: wave/particle properties of mass
Replies: 3
Views: 54

wave/particle properties of mass

So if electrons have both wave and particle properties, does that mean that anything with mass have both wave and particle properties as well?
by Jacob Puchalski 1G
Wed Oct 09, 2019 3:32 pm
Forum: Properties of Electrons
Topic: Energy of Electron
Replies: 10
Views: 161

Re: Energy of Electron

He means that each electron can only hold specific amounts of energy. That's why the energy levels are n=1, n=2, n=3,... instead of any random number like n=1.74.
by Jacob Puchalski 1G
Wed Oct 09, 2019 3:25 pm
Forum: Properties of Light
Topic: Kinetic Energy
Replies: 2
Views: 63

Re: Kinetic Energy

If you look at electromagnetic radiation as individual photons, a higher intensity basically increases the number of photons - each photon still contains the same amount of energy.
by Jacob Puchalski 1G
Thu Oct 03, 2019 5:32 pm
Forum: Limiting Reactant Calculations
Topic: Percent yields/error
Replies: 3
Views: 84

Percent yields/error

What's the difference between percent yield and percent error?
by Jacob Puchalski 1G
Thu Oct 03, 2019 5:27 pm
Forum: Properties of Light
Topic: What does μm mean?
Replies: 4
Views: 84

Re: What does μm mean?

It's a unit of measurement (micrometer) which is 10^-6 of a meter.
by Jacob Puchalski 1G
Thu Oct 03, 2019 5:19 pm
Forum: Significant Figures
Topic: Sig Figs in Mulitstep Problems
Replies: 10
Views: 118

Re: Sig Figs in Mulitstep Problems

I think it's best to round throughout the steps to an extent; we should round enough so that it's easier to keep track of the numbers but not so much that it'll affect the final answer. Maybe around four sig figs?
by Jacob Puchalski 1G
Thu Oct 03, 2019 5:06 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Lab experiments- accuracy vs precision
Replies: 7
Views: 147

Re: Lab experiments- accuracy vs precision

Even if it isn't accurate, precision can be helpful because you know that at least your calculations are consistent. It can then be easier to fix any errors.
by Jacob Puchalski 1G
Thu Oct 03, 2019 4:54 pm
Forum: General Science Questions
Topic: Naming compounds
Replies: 6
Views: 112

Re: Naming compounds

Later in the course we'll need to, but for now anything uncommon will be provided for.

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