## Search found 70 matches

Thu Jan 21, 2021 8:34 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Kelvin or Celsius?
Replies: 59
Views: 1325

### Re: Kelvin or Celsius?

Use Kelvin.
Thu Jan 21, 2021 8:34 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Ka vs. Kb
Replies: 30
Views: 80

### Re: Ka vs. Kb

Ka is the equilibrium constant for acids, and Kb is the equilibrium constant for bases. Ka*Kb=Kw=1*10^-14
Thu Jan 21, 2021 8:33 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Ka correlation to strength of an acid
Replies: 20
Views: 59

### Re: Ka correlation to strength of an acid

A larger Ka is a stronger acid.
Thu Jan 21, 2021 8:32 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Diprotic Acids
Replies: 1
Views: 14

### Diprotic Acids

What K value do I use for solving pH of diprotic acids, K1 or K2?
Thu Jan 21, 2021 8:30 pm
Forum: Phase Changes & Related Calculations
Topic: Heat and temperature change
Replies: 5
Views: 10

### Heat and temperature change

Hi!
Can someone explain the idea that temperature does not change when heat is added during boiling?
Thank you
Wed Jan 13, 2021 7:28 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: pKw
Replies: 7
Views: 47

### Re: pKw

Equilibrium constants are only a set value for a certain temperature, and Kw is the equilibrium constant for water at 25 degrees celsius, which is why it always equals 10^-14.
Wed Jan 13, 2021 7:26 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Temperature
Replies: 38
Views: 94

### Re: Temperature

If you know whether the reaction is endothermic or exothermic, you can determine which would be favored. In an exothermic reaction, if temperature is increased, the reaction shifts left, as heat can be seen as a product of the reaction. In an endothermic reaction, if temperature is increased, the re...
Wed Jan 13, 2021 7:23 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Temperature & K for Acids and Bases
Replies: 4
Views: 31

### Re: Temperature & K for Acids and Bases

We typically use 25 degrees Celsius as our standard temperature.
Le Chatelier's principle says that in an endothermic reaction, Ka increases and therefore pKa decreases.
As far as acids and bases, it does not change their 100% ionization though, if that is what you're asking.
Wed Jan 13, 2021 7:18 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Left vs. Right
Replies: 29
Views: 93

### Re: Left vs. Right

The statements are the same!
Wed Jan 13, 2021 7:17 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: How to calculate the pKa
Replies: 12
Views: 80

### Re: How to calculate the pKa

If you are given pKa, use -log(Ka) to solve, and Ka= [H+][A-]/[HA]. I believe that the whether or not you are given pKa just depends on the question.
Fri Jan 08, 2021 7:39 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Temperature Change
Replies: 4
Views: 20

### Re: Temperature Change

K decreases with an increase in temperature (exothermic!) and K increases when temperature decreases (endothermic!).
Fri Jan 08, 2021 7:37 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kc to Kp
Replies: 8
Views: 57

### Kc to Kp

How do I convert Kc to Kp?
Thu Jan 07, 2021 7:58 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Finding Kc given K
Replies: 5
Views: 25

### Finding Kc given K

Hi!
Can someone explain how to find Kc when given a reaction and its eq. constant K?
Thu Jan 07, 2021 7:56 pm
Forum: Ideal Gases
Topic: reversing reactions
Replies: 80
Views: 387

### Re: reversing reactions

It becomes the inverse reaction, or 1/K
Thu Jan 07, 2021 7:52 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kc
Replies: 11
Views: 40

### Kc

When we are using ICE for to find equilibrium values, do we always use molarity?
Fri Dec 11, 2020 6:33 pm
Forum: Amphoteric Compounds
Topic: Amphoteric Compounds
Replies: 3
Views: 38

### Amphoteric Compounds

Are there other amphoteric compounds outside of the metalloids?
Fri Dec 11, 2020 6:32 pm
Forum: Lewis Acids & Bases
Topic: Acid and Base Exceptions
Replies: 1
Views: 42

### Acid and Base Exceptions

For the general rule that metal oxides react with water to form strong bases, and nonmetal oxides react with water to form acids, are there any exceptions to this rule?
Fri Dec 11, 2020 6:26 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: proton transfer equilibria
Replies: 1
Views: 17

### proton transfer equilibria

What type of products form in proton transfer equilibria?
Fri Dec 11, 2020 6:25 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: pH of salt solutions
Replies: 1
Views: 20

### pH of salt solutions

Do strong vs weak conjugate bases play a role in determining the pH of a salt solution?
Tue Dec 08, 2020 12:51 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Shape
Replies: 6
Views: 37

### Shape

On the test, if we are asked to give the shape of a molecule, do we give the electron-group shape name, or the molecular shape?
Thu Dec 03, 2020 5:22 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Acid strength and bond length
Replies: 11
Views: 87

### Re: Acid strength and bond length

Bonds that are longer are more easily broken, making them present in strong acids because they dissociate well.
Thu Dec 03, 2020 5:20 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Tetrahedral vs Square Planar
Replies: 6
Views: 49

### Re: Tetrahedral vs Square Planar

We don't need to distinguish between the two, just know that the coordination number is 4!
Thu Dec 03, 2020 5:19 pm
Forum: Naming
Topic: Formula Order
Replies: 4
Views: 42

### Re: Formula Order

I agree, I don't think that formula order matters, only when writing out the name.
Thu Dec 03, 2020 5:18 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Denticity
Replies: 2
Views: 17

### Denticity

Hi! Can someone explain what denticity is?
Thu Dec 03, 2020 5:10 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligand
Replies: 2
Views: 21

### Ligand

What is an example of a bidentate ligand?
Thu Dec 03, 2020 5:08 pm
Forum: Naming
Topic: Naming Coordinate compounds
Replies: 3
Views: 23

### Naming Coordinate compounds

When naming coordinate compounds, does it matter if it is one long name or if we separate each part of the name with spaces in between?
Mon Nov 30, 2020 11:16 am
Forum: Naming
Topic: Ligands
Replies: 2
Views: 44

### Ligands

When naming ligands, why is ammonia changed to ammine? Or what is the rule for naming?
Sat Nov 28, 2020 6:42 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Axial vs Equatorial
Replies: 3
Views: 42

### Axial vs Equatorial

How do we know where to put lone pairs, such as in the axial or equatorial position?
Sat Nov 28, 2020 6:40 pm
Forum: Hybridization
Topic: hybridization
Replies: 5
Views: 61

### Re: hybridization

I believe s and p orbitals will only be tested on.
Thu Nov 26, 2020 2:58 pm
Forum: Sigma & Pi Bonds
Topic: Delocalized
Replies: 3
Views: 34

### Delocalized

What is the difference between a pi bond and a delocalized pi bond?
Thu Nov 26, 2020 2:56 pm
Forum: Electronegativity
Topic: Periodic Table Trend
Replies: 37
Views: 387

### Re: Periodic Table Trend

Ionization energy and electronegativity both follow the same trend- they increase across a period and decrease down a group.
Thu Nov 26, 2020 2:54 pm
Forum: Hybridization
Topic: e density
Replies: 30
Views: 133

### Re: e density

Yes, every area with a lone pair or bond is an area of e- density.
Fri Nov 20, 2020 2:48 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles (<109 or 104.5, etc)
Replies: 8
Views: 56

### Re: Bond Angles (<109 or 104.5, etc)

I believe we just have to know that it would be less than a certain value, and not a specific value.
Fri Nov 20, 2020 2:48 pm
Forum: Ionic & Covalent Bonds
Topic: Polar Bonds
Replies: 19
Views: 111

### Re: Polar Bonds

Hi,
I usually look for lone pairs or symmetry when looking to see if a molecule is polar or not. Also, I look to see if the central atom has all the same types of atoms surrounding it, as sometimes if one is more electronegative than the other it cause cause a slight pull of e-.
Fri Nov 20, 2020 2:46 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: H20 Bent Structure
Replies: 14
Views: 107

### Re: H20 Bent Structure

H2O has a bent structure because it has two lone pairs on the oxygen atom. This causes repulsion of the two hydrogen atoms and pushes them downwards, causing a bent structure.
Wed Nov 18, 2020 11:37 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Seesaw
Replies: 1
Views: 35

### Seesaw

What are the bond angles in a seesaw shape?
Wed Nov 18, 2020 11:27 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Seesaw
Replies: 4
Views: 44

### Seesaw

Hi!
Can someone explain why the lone pair in the seesaw shape is found on the equatorial plane and not the axial plane?
Wed Nov 18, 2020 11:24 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Square Planar vs. Tetrahedral
Replies: 7
Views: 66

### Re: Square Planar vs. Tetrahedral

In square planar, the four atoms are all in the same plane and make up the four corners of it. While in tetrahedral, they are not all in the same plane.
Fri Nov 13, 2020 9:49 am
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability
Replies: 6
Views: 45

### Re: Polarizability

Between two anions in the same row, would an anion with a -2 charge be more or less polarizable than an anion with a -1 charge? I think it is just by anion size. So whichever one is larger will be more polarizable even if the charge is a smaller magnitude. Someone, please correct me if I am wrong! ...
Thu Nov 12, 2020 6:20 pm
Forum: Ionic & Covalent Bonds
Topic: Multiplicity
Replies: 1
Views: 18

### Multiplicity

What is the multiplicity of a covalent bond?
Thu Nov 12, 2020 12:41 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge vs Octet Rule
Replies: 12
Views: 226

### Re: Formal Charge vs Octet Rule

Yes, use the octet rule to draw your lewis diagrams, then assign formal charges to the atoms.
Thu Nov 12, 2020 12:39 pm
Forum: Lewis Structures
Topic: Radicals
Replies: 12
Views: 38

### Re: Radicals

Radicals are any molecules that have an unpaired electron, and they form when atoms or molecules gain or lose electrons.
Wed Nov 11, 2020 7:33 pm
Forum: Dipole Moments
Topic: Polar covalent bonds
Replies: 5
Views: 18

### Polar covalent bonds

Are the dipole-dipole the same as polar covalent bonds?
Wed Nov 11, 2020 7:31 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability
Replies: 6
Views: 45

### Polarizability

Hi, I know that the polarizability is how easily the electrons are distorted, but can someone explain what the Polarizability of Anions, The Polarizing Power of Cations is specifically pertaining to?
Fri Nov 06, 2020 2:43 pm
Forum: Trends in The Periodic Table
Topic: Bond Length
Replies: 5
Views: 31

### Bond Length

Does electronegativity affect bond length?
Fri Nov 06, 2020 2:38 pm
Forum: Ionic & Covalent Bonds
Topic: Atomic Radius
Replies: 38
Views: 224

### Re: Atomic Radius

When you move across the periodic table, the atomic radius gets smaller because with more protons, there is a greater pull on the electrons. Ultimately, this results in a smaller atomic radius.
Wed Nov 04, 2020 10:48 am
Forum: Octet Exceptions
Topic: Radicals
Replies: 5
Views: 36

### Radicals

What are some examples of when we ingest radicals?
Tue Nov 03, 2020 5:09 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge and Resonance Structures
Replies: 4
Views: 44

### Formal Charge and Resonance Structures

I know that it is better to have negative charges on the most electronegative elements, but for a structure that has an overall charge of -1, would it be better to have a +1 on N and two -1 oxygen charges, or just one -1 charge on a single O atom?
Tue Nov 03, 2020 5:07 pm
Forum: Trends in The Periodic Table
Topic: Ionic Radius
Replies: 8
Views: 62

### Ionic Radius

For ions that all have the same electron configuration, so the same number of elements, but are different elements, such as Na+ and F-, how do you determine which has the smaller radius?
Fri Oct 30, 2020 10:38 am
Forum: Properties of Light
Topic: Sapling Question 24
Replies: 4
Views: 31

### Sapling Question 24

Hi, I am having difficulties with Sapling Problem 24. I am not sure how to determine whether or not a wavelength is compatible or not?
Wed Oct 28, 2020 10:43 pm
Forum: General Science Questions
Topic: polyatomic ions
Replies: 6
Views: 97

### Re: polyatomic ions

Hi!
I think that Dr. Lavelle said we would not need to memorize polyatomic ions, and that they would be given to us if we had to write out chemical equations.
Wed Oct 28, 2020 10:39 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 3d and 4s orbitals
Replies: 9
Views: 80

### Re: 3d and 4s orbitals

Hi!
The 3d state has less energy than the 4s energy state, which is why it is written first when writing out electron configurations.
Tue Oct 27, 2020 10:17 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Bohr Equation
Replies: 4
Views: 37

### Bohr Equation

What is the significance of the negative sign in Bohr's equation?
Tue Oct 27, 2020 10:16 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration
Replies: 4
Views: 29

### Electron Configuration

Would 4s^2 3d^1 be wrong instead of 3d^1 4s^2 on tests?
Fri Oct 23, 2020 9:30 am
Forum: *Shrodinger Equation
Topic: Schrodinger Equation
Replies: 2
Views: 30

### Schrodinger Equation

Hi, I am a little bit confused as to when I should be using Schrodinger's equation, or what the overall purpose of it is for?
Wed Oct 21, 2020 3:15 pm
Forum: *Particle in a Box
Topic: Midterm 1
Replies: 16
Views: 258

### Midterm 1

Will we be tested on the particle in a box on the midterm?
Wed Oct 21, 2020 3:06 pm
Forum: *Shrodinger Equation
Topic: Schrodinger Equation, H
Replies: 2
Views: 33

### Schrodinger Equation, H

Hi!
Can someone elaborate on what H is in the Schrodinger equation?
Thank you
Wed Oct 21, 2020 3:04 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Calculating Velocity
Replies: 5
Views: 70

### Calculating Velocity

I know that if you calculate a velocity greater than the speed of light, then it is physically impossible and an incorrect model, but can the velocity be equal to the speed of light?
Tue Oct 20, 2020 8:54 pm
Forum: DeBroglie Equation
Topic: Problem 1B.20
Replies: 3
Views: 47

### Problem 1B.20

Hi, I have having issues with problem 1B.20 from the book:
What is the wavelength of an electron when the distance it travels in 1 s is equal to its wavelength?
and was wondering how I should set up this problem?
Mon Oct 19, 2020 10:27 am
Forum: DeBroglie Equation
Topic: Units [ENDORSED]
Replies: 3
Views: 48

### Units[ENDORSED]

When I use the DeBroglie equation, should the units for mass be in g or kg?
Thu Oct 15, 2020 12:55 pm
Forum: Einstein Equation
Topic: Converting from MHz to Hz
Replies: 5
Views: 45

### Converting from MHz to Hz

Hi!
I was doing problem 1.A.9 in the textbook, and was given the frequency= 300 MHz and was told to find the wavelength. Each time I solve it I keep getting 0.1 m, while the answer is 1 nm.
If anyone could help I would appreciate it!
Wed Oct 14, 2020 5:08 pm
Forum: Photoelectric Effect
Topic: Using Avogadro's number
Replies: 2
Views: 32

### Using Avogadro's number

In the lecture, Dr. Lavelle mentioned that the energy of the photon is energy/electron, while the work function is in energy/mol, and that we would need to use Avogadro's number to convert the energy of the work function to energy/atom. What would a question look like where we would need to convert ...
Wed Oct 14, 2020 5:04 pm
Forum: Photoelectric Effect
Topic: Work Function
Replies: 6
Views: 44

### Re: Work Function

Yes, the work function, or threshold energy, is the amount of energy required to eject an electron from the surface!
Wed Oct 14, 2020 4:59 pm
Forum: Photoelectric Effect
Topic: Excess energy
Replies: 20
Views: 135

### Re: Excess energy

Hi!
1/2mv^2 is used in the photoelectric effect equation, 1/2mv^2= hv - (work function) to find kinetic energy of the ejected electron
Wed Oct 14, 2020 11:12 am
Forum: Einstein Equation
Topic: m vs nm
Replies: 66
Views: 444

### m vs nm

On the test, will we need to format our answers in meters or nanometers when solving for wavelength?
Fri Oct 09, 2020 2:06 pm
Forum: Balancing Chemical Reactions
Topic: State of matter in reaction
Replies: 9
Views: 37

### Re: State of matter in reaction

Hi! I have a follow up question with the state of matter in reactions.
Is it necessary to display their states when writing them out in equations, or will we be deducted points for not including them?
Fri Oct 09, 2020 2:00 pm
Forum: Properties of Light
Topic: Electric Field Vectors
Replies: 4
Views: 47

### Electric Field Vectors

Hi! So I understand that waves are composed of electric and magnetic fields, but I was wondering if anyone could explain electric field vectors?
Fri Oct 09, 2020 1:58 pm
Forum: Limiting Reactant Calculations
Topic: Determining Limiting Reactant
Replies: 7
Views: 87

### Determining Limiting Reactant

For limiting reactants, if both the reactants are in a 1:1 ratio, are both reactants considered a LR or neither?
Fri Oct 09, 2020 1:21 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical and Molecular Formula
Replies: 17
Views: 124

### Re: Empirical and Molecular Formula

Hi Carolina,
Yes, the empirical and molecular formula can be the same. The empirical formula is a simplified version of the molecular formula, but it is possible for the molecular formula can also be in the most simplified state.
Wed Oct 07, 2020 10:51 am
Forum: Molarity, Solutions, Dilutions
Topic: Sapling HW Question 5
Replies: 10
Views: 111

### Re: Sapling HW Question 5

Hi! I have a follow up question regarding mass percentage. Do we always format our answers with the decimal place to the hundredth?

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