Search found 60 matches

by Niveda_B_3I
Sat Mar 16, 2019 1:06 pm
Forum: Calculating Work of Expansion
Topic: Integrate Rate Law
Replies: 2
Views: 174

Re: Integrate Rate Law

ln[A] vs time is the rate plot for a first order function.
by Niveda_B_3I
Sat Mar 16, 2019 1:05 pm
Forum: Ideal Gases
Topic: Cell Diagram/Ecell
Replies: 8
Views: 291

Re: Cell Diagram/Ecell

The anode is oxidized, loses electrons.
The cathode is reduced, gains electrons.
by Niveda_B_3I
Sat Mar 16, 2019 1:03 pm
Forum: General Rate Laws
Topic: Rate Law
Replies: 1
Views: 170

Re: Rate Law

The rate law depends on how quickly a product is formed, and that depends on how quickly the reactants used to make it up are used up.
by Niveda_B_3I
Thu Mar 07, 2019 9:54 am
Forum: Balancing Redox Reactions
Topic: Writing half reactions
Replies: 7
Views: 142

Re: Writing half reactions

The H+ would be with the Cr2O7 since the oxygen atoms in it are balanced with H20, and the H20 are balanced with H+
by Niveda_B_3I
Thu Mar 07, 2019 9:46 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: E cell
Replies: 5
Views: 102

Re: E cell

E^o is the standard reduction potential, or basically how badly the molecule wants to be reduced (positive means it wants to be reduced more, negative means it wants to be oxidized more). Ecell basically refers to the total standard reduction potential of the cell with E^o of the cathode - E^o of th...
by Niveda_B_3I
Thu Mar 07, 2019 9:39 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Instantaneous vs Average
Replies: 11
Views: 160

Re: Instantaneous vs Average

Instantaneous change would imply a derivative, because you're finding the changing at a certain time t, versus average would be you finding the change over a period of time, from t1 to t2.
by Niveda_B_3I
Thu Mar 07, 2019 9:36 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: how is kinetics different?
Replies: 17
Views: 281

Re: how is kinetics different?

Kinetics tells you the rate of the reaction; a reaction might be deemed spontaneous due to thermodynamics, but sometimes that reaction occurs very slowly. Kinetics tells you how fast or slow that reaction occurs.
by Niveda_B_3I
Tue Feb 19, 2019 12:46 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Isobaric
Replies: 11
Views: 397

Re: Isobaric

Isobaric basically means there is no change in pressure, which means you can have work and heat changing your internal energy.
by Niveda_B_3I
Tue Feb 19, 2019 12:44 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Delta G a state function?
Replies: 23
Views: 328

Re: Delta G a state function?

Free energy is a state function, because it involves enthalpy and entropy, two other state functions.
by Niveda_B_3I
Tue Feb 19, 2019 12:43 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Test 3
Replies: 10
Views: 187

Re: Test 3

It should cover whatever we learned on the Friday lecture of Week 6, and everything covered in Week 7.
by Niveda_B_3I
Tue Feb 19, 2019 12:42 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs free energy
Replies: 7
Views: 117

Re: Gibbs free energy

Gibbs free energy is the amount of energy that is available to do work, and the equation shows the relationship between entropy and enthalpy as well.
by Niveda_B_3I
Tue Feb 19, 2019 12:41 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reversible Reactions
Replies: 8
Views: 342

Re: Reversible Reactions

Are reversible reactions are isothermal!
by Niveda_B_3I
Tue Feb 19, 2019 12:39 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Pressure Equation
Replies: 7
Views: 302

Re: Pressure Equation

When you are calculating an entropy change due to pressure, and not volume.
by Niveda_B_3I
Tue Feb 19, 2019 12:38 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: delta S
Replies: 7
Views: 153

Re: delta S

The change in entropy would be zero when the heat transferred into or out of the system is 0.
by Niveda_B_3I
Sun Feb 10, 2019 4:54 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Delta U
Replies: 8
Views: 151

Re: Delta U

The change in internal energy could be 0
if q = -w
if T = 0
and if the system is isothermal and the reaction is reversible
by Niveda_B_3I
Sun Feb 10, 2019 4:47 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Cv/Cp versus R
Replies: 4
Views: 108

Re: Cv/Cp versus R

Cv is for when volume is constant, and Cp is used for when pressure is constant.
by Niveda_B_3I
Sun Feb 10, 2019 4:46 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: w=-PdeltaV
Replies: 6
Views: 124

Re: w=-PdeltaV

-PdeltaV would be used if your external pressure is constant, and with irreversible reactions.
by Niveda_B_3I
Sun Feb 03, 2019 4:34 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: open system
Replies: 8
Views: 165

Re: open system

pressure of the system=the pressure of the exterior
by Niveda_B_3I
Sun Feb 03, 2019 4:32 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Calorimeter
Replies: 6
Views: 112

Re: Calorimeter

We will have to know how to do calculations involving calorimetry.
by Niveda_B_3I
Sun Feb 03, 2019 4:32 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy
Replies: 3
Views: 75

Re: Enthalpy

On the other hand, entropy is basically the degree of disorder.
by Niveda_B_3I
Thu Jan 24, 2019 11:15 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5%
Replies: 10
Views: 189

Re: 5%

Your x has to be less than 5% of the initial concentration for your assumption/approximation to be valid
by Niveda_B_3I
Thu Jan 24, 2019 11:14 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Ka and pH
Replies: 6
Views: 113

Re: Ka and pH

Not really. You'd have to use the Ka or Kb value to solve an ICE table and find the concentration of Hydronium ions to find that.
by Niveda_B_3I
Thu Jan 24, 2019 11:11 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Quiz #1 This friday
Replies: 5
Views: 167

Re: Quiz #1 This friday

I had Lavelle last quarter, and the best way to study is to do the homework problems, and the practice worksheets that UA's like Karen and Lyndon give and attend their sessions. Also read (or at least skim) the textbook.
by Niveda_B_3I
Sat Jan 19, 2019 5:20 pm
Forum: Ideal Gases
Topic: PV=nRT
Replies: 8
Views: 356

Re: PV=nRT

PV = nRT shows the relationship between pressure and concentration so it would be used to convert Kp to Kc and vice versa.
by Niveda_B_3I
Sat Jan 19, 2019 5:17 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Weak Acid & Salt
Replies: 4
Views: 71

Re: Weak Acid & Salt

since it's a asalt, the potassium ions dissociate completely on both sides, and don't really count toward finding your equilibrium constant value.
by Niveda_B_3I
Sat Jan 19, 2019 5:16 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Ka vs. Kb
Replies: 12
Views: 346

Re: Ka vs. Kb

Ka time Kb is Kw, and pKa + pKb is 14, and also equal to pKw
by Niveda_B_3I
Wed Jan 09, 2019 4:55 pm
Forum: Ideal Gases
Topic: Temperature in PV=nRT
Replies: 9
Views: 531

Re: Temperature in PV=nRT

Kelvin is the SI unit for temperature.
by Niveda_B_3I
Wed Jan 09, 2019 4:54 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: What does it mean when a reaction is at equilibrium?
Replies: 4
Views: 76

Re: What does it mean when a reaction is at equilibrium?

However, make sure you remember that just because a reaction is at equilibrium, it doesn't necessarily mean that the reaction is over.
by Niveda_B_3I
Wed Jan 09, 2019 4:48 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K and Kc
Replies: 8
Views: 134

Re: K and Kc

You can determine whether you should be using Kc or Kp depending on the states of the molecules in the chemical equation, or also the information given to you.
by Niveda_B_3I
Thu Dec 06, 2018 11:58 pm
Forum: Naming
Topic: Naming
Replies: 3
Views: 83

Re: Naming

We know that potassium has a +1 charge, and we know that cyano has a -1 charge and there are 4 cyano so there's a -4 charge but nickelate has a +2 charge so in general the anion has a -2 charge. So there has to be 2 potassium ions so that it is a neutral compound.
by Niveda_B_3I
Thu Dec 06, 2018 11:54 pm
Forum: Conjugate Acids & Bases
Topic: 12.1 6th edition
Replies: 2
Views: 83

Re: 12.1 6th edition

The conjugate base is just the deprotonated acid.
by Niveda_B_3I
Thu Dec 06, 2018 11:53 pm
Forum: Identifying Acidic & Basic Salts
Topic: Salts cause acidity
Replies: 3
Views: 106

Re: Salts cause acidity

There has to be a proton (aka hydrogen) that can be pulled off the acid and create a H3O+ ion to increase the acidity of the solution.
by Niveda_B_3I
Sun Dec 02, 2018 2:43 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Number
Replies: 10
Views: 158

Re: Coordination Number

Coordination number is basically the number of bonded atoms to the central atom.
by Niveda_B_3I
Sun Dec 02, 2018 2:40 pm
Forum: Biological Examples
Topic: acids
Replies: 5
Views: 90

Re: acids

The stomach and digestive system in general have a layer of protection. Your ski is that layer of protection for the rest of your body (like the outside) so when you have a cut, there's no protection.
by Niveda_B_3I
Sun Dec 02, 2018 2:38 pm
Forum: Naming
Topic: With Respect to the Final
Replies: 9
Views: 211

Re: With Respect to the Final

Probably both. What if you're asked to find the molarity of a solution that is made up of water and a compound but they give you the name of the compound rather than the molecular formula?
by Niveda_B_3I
Sun Nov 25, 2018 3:15 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape
Replies: 7
Views: 140

Re: Molecular Shape

The arrangement of the electron density would be trigonal bipyramidal, but the arrangement of the atoms would be tetrahedral, since there's a lone pair. As a result, you would end up with seesaw structure.
by Niveda_B_3I
Sun Nov 25, 2018 3:14 pm
Forum: Hybridization
Topic: sp orbitals
Replies: 3
Views: 87

Re: sp orbitals

Furthermore, sp3 means there's one sigma bond, sp2 means one sigma bond, one pi bond, and sp means there's one sigma bond and two pi bonds.
by Niveda_B_3I
Sun Nov 25, 2018 3:10 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Shapes Not covered in Lecture
Replies: 10
Views: 203

Re: Shapes Not covered in Lecture

It's probably a good idea to know that, especially if it shows up in the textbook. We can probably assume from previous tests that it would be fair game for the test since the same thing happened with nodes on the second test.
by Niveda_B_3I
Mon Nov 19, 2018 1:39 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Octahedral to Square Planar
Replies: 7
Views: 109

Re: Octahedral to Square Planar

A square planar has an octahedra; electron density arrangement, but since two of those areas of electron density are lone pairs, and only four atoms are bonded to the central atom, it is square planar in molecular shape.
by Niveda_B_3I
Mon Nov 19, 2018 1:19 pm
Forum: Hybridization
Topic: Sigma/Pi bonds
Replies: 6
Views: 160

Re: Sigma/Pi bonds

Also, it's good to know that:

single bond - one sigma
double bond - one sigma, one pi
triple bond - one sigma, two pi

etc.
by Niveda_B_3I
Mon Nov 19, 2018 1:17 pm
Forum: Hybridization
Topic: Electron Density Shape
Replies: 2
Views: 52

Re: Electron Density Shape

Basically the electron density arrangement is what would give you your hybridization orbitals. So if your electron density arrangement is tetrahedral, then you would have sp3 hybridization. However, your molecular shape is actually based on the number of atoms bonded to the central atom, so if you h...
by Niveda_B_3I
Sun Nov 11, 2018 7:03 pm
Forum: Octet Exceptions
Topic: Radicals
Replies: 16
Views: 553

Re: Radicals

Also, you wouldn't make the atom that has the most electronegativity a radical, because it would want a full octet.
by Niveda_B_3I
Sun Nov 11, 2018 7:02 pm
Forum: Resonance Structures
Topic: Resonance structures
Replies: 7
Views: 346

Re: Resonance structures

The actual structure is the resonance hybrid, but we draw out the resonance structure to show the possible positions of the delocalized electrons.
by Niveda_B_3I
Sun Nov 11, 2018 7:00 pm
Forum: Electronegativity
Topic: Electron Affinity vs. Ionization Energy
Replies: 8
Views: 180

Re: Electron Affinity vs. Ionization Energy

Electron affinity is the amount of energy released when an atom is given an electron, and ionization energy is the energy not takes to remove an electron.
by Niveda_B_3I
Sun Nov 04, 2018 10:08 pm
Forum: Electronegativity
Topic: Garlic Bread Review 10d
Replies: 3
Views: 125

Re: Garlic Bread Review 10d

also, this half shell stability extends to things like Boron and why it doesn't need a full octet.
by Niveda_B_3I
Sun Nov 04, 2018 5:15 pm
Forum: Resonance Structures
Topic: Resonance Structures on the Midterm
Replies: 3
Views: 110

Re: Resonance Structures on the Midterm

Also if you draw all the resonance structures, draw arrows between them!
by Niveda_B_3I
Sun Nov 04, 2018 5:11 pm
Forum: Lewis Structures
Topic: 12b from the GarBreadium worksheet
Replies: 3
Views: 76

Re: 12b from the GarBreadium worksheet

It just symbolizes that the molecule is negatively charged, and that charge should be equal to your overall formal charge.
by Niveda_B_3I
Sun Oct 28, 2018 4:26 pm
Forum: Trends in The Periodic Table
Topic: Atomic Radius
Replies: 8
Views: 158

Re: Atomic Radius

You just need to know trends, and maybe why the trends make sense.
by Niveda_B_3I
Sun Oct 28, 2018 4:11 pm
Forum: Ionic & Covalent Bonds
Topic: Valence electrons
Replies: 8
Views: 92

Re: Valence electrons

The last shell is the valence shell, and the number of valence electrons is the number of electrons in the last shell (determined by n value).
by Niveda_B_3I
Sun Oct 28, 2018 3:54 pm
Forum: Ionic & Covalent Bonds
Topic: Hydrogen Bonds
Replies: 5
Views: 75

Re: Hydrogen Bonds

Hydrogen bonds, from what I remember from high school chem, were the strongest intermolecular forces, but bonds are technically between molecules, which would explain why they're actually bonds like someone had mentioned earlier.
by Niveda_B_3I
Sun Oct 21, 2018 9:11 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Px. Py, Pz
Replies: 6
Views: 195

Re: Px. Py, Pz

Hi Nikitha xD
Basically there's 3 p orbitals, px py and pz. The x,y, and z simply tell you the orientation of the orbitals. However, it doesn't really matter in terms of when you're doing electron configuration or anything like that.
by Niveda_B_3I
Sun Oct 21, 2018 9:05 pm
Forum: *Shrodinger Equation
Topic: Shrodinger Equation on Test
Replies: 5
Views: 165

Re: Shrodinger Equation on Test

Really, the concepts you should know based on Schrodinger's are the fact that there's different energy levels and the types of orbitals you can find at each one, as well as properties of them. (For example, the s-orbital is the only orbital with symmetric electron distribution).
by Niveda_B_3I
Sun Oct 21, 2018 9:02 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg Equation Confusion
Replies: 4
Views: 117

Re: Heisenberg Equation Confusion

Given that you know either the change in momentum or position, you should be able to find the minimum value of the other using Heisenberg's.
by Niveda_B_3I
Thu Oct 11, 2018 6:00 pm
Forum: Photoelectric Effect
Topic: work function
Replies: 4
Views: 125

Re: work function

Basically, the work function (threshold energy) is going to be equal to the energy of the photon (hv) minus the kinetic energy of the electron upon removal (excess energy). Of course, if the threshold energy is not equal to or less than the energy of the photon, then the electron will not be removed...
by Niveda_B_3I
Thu Oct 11, 2018 5:49 pm
Forum: Properties of Light
Topic: Photon energy
Replies: 3
Views: 74

Re: Photon energy

Also, it's important to note that the energy of a photon is determined by E = hv, where h is Planck's constant and v is the frequency of light.
by Niveda_B_3I
Thu Oct 11, 2018 5:47 pm
Forum: Photoelectric Effect
Topic: Empirical Equation
Replies: 4
Views: 89

Re: Empirical Equation

The threshold energy differs between various metals, just like the spectra for different elements is different. This is because the change in energy from level to level is different depending on the element.
by Niveda_B_3I
Fri Oct 05, 2018 1:28 pm
Forum: Balancing Chemical Reactions
Topic: Balancing Chemical Reactions with Heat
Replies: 6
Views: 105

Re: Balancing Chemical Reactions with Heat

Regardless of the heat, it's still a chemical reaction. So the Law of Conservation of Mass applies as it usually would, and you balance the equation normally.
by Niveda_B_3I
Fri Oct 05, 2018 1:15 pm
Forum: Empirical & Molecular Formulas
Topic: When to double moles
Replies: 13
Views: 259

Re: When to double moles

It's never going to be completely accurate. You just have to round to the nearest whole number.
by Niveda_B_3I
Fri Oct 05, 2018 1:06 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: % Yield
Replies: 8
Views: 380

Re: % Yield

There's no such thing as an unacceptable % yield. % yield is simply the comparison of the actual yield to the theoretical yield.

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