Search found 60 matches

by MariahClark 2F
Sun Mar 17, 2019 7:51 pm
Forum: Balancing Redox Reactions
Topic: Reduction powers
Replies: 2
Views: 123

Re: Reduction powers

Wouldn’t you determine that using oxidizing potential ?
by MariahClark 2F
Sun Mar 17, 2019 7:45 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: bomb calorimeter
Replies: 6
Views: 269

Re: bomb calorimeter

Yea w=0 in that case
by MariahClark 2F
Sun Mar 17, 2019 7:32 pm
Forum: Balancing Redox Reactions
Topic: Oxidizing powers
Replies: 2
Views: 114

Re: Oxidizing powers

An element with a high reduction potential is a powerful oxidizing agent.
by MariahClark 2F
Sun Mar 17, 2019 7:28 pm
Forum: Biological Examples
Topic: ATP example
Replies: 3
Views: 264

Re: ATP example

Wouldn’t the reaction be exergonic since it’s giving off energy and not requiring it?
by MariahClark 2F
Sun Mar 17, 2019 7:25 pm
Forum: General Science Questions
Topic: sig figs
Replies: 4
Views: 149

Re: sig figs

In that case I would do 2 to account for the decimal and what not
by MariahClark 2F
Sun Mar 17, 2019 1:51 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Midterm Q3-C
Replies: 4
Views: 124

Re: Midterm Q3-C

Thank you so much!
by MariahClark 2F
Sun Mar 17, 2019 1:38 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Heat Capacity Intensive or Extensive?
Replies: 1
Views: 117

Re: Heat Capacity Intensive or Extensive?

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.
by MariahClark 2F
Sun Mar 17, 2019 1:16 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 6N.1
Replies: 1
Views: 90

Re: 6N.1

Look at the order of the elements in the actual equation that is given to you. The half reactions displayed are backwards in a sense, which is how you can get the cell potential value. Mn is oxidized to become Mn2+ and Ti2+ is reduced to become Ti.
by MariahClark 2F
Sun Mar 17, 2019 1:11 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Midterm Q3-C
Replies: 4
Views: 124

Midterm Q3-C

Can someone please explain the reasoning behind the answer for Q3C on the midterm please, Im thinking way too hard.
by MariahClark 2F
Sun Mar 17, 2019 12:39 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: salt bridge
Replies: 4
Views: 152

Re: salt bridge

A salt bridge is used to neutralize the two solutions in order to prevent them from becoming too negative or too positive. This way, a current can still be transferred across the wire.
by MariahClark 2F
Sun Mar 17, 2019 12:18 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Liquids and Solids
Replies: 2
Views: 111

Re: Liquids and Solids

p\Pure liquids and pure solids have activities that are one (they don't appear in the mass action expression). Thus if you add more of them they will not affect the equilibrium at all. Solubility is a situation like this. If you have a saturated solution and you add more solid nothing happens (the r...
by MariahClark 2F
Sun Mar 17, 2019 12:10 am
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: higher entropies
Replies: 1
Views: 96

Re: higher entropies

Higher entropy means an increase in disorder.
by MariahClark 2F
Sun Mar 17, 2019 12:07 am
Forum: *Enzyme Kinetics
Topic: catalyst
Replies: 1
Views: 106

Re: catalyst

Enzymes are proteins functioning as catalysts that speed up reactions by lowering the activation energy. A simple and succinct definition of an enzyme is that it is a biological catalyst that accelerates a chemical reaction without altering its equilibrium.
by MariahClark 2F
Sun Mar 17, 2019 12:03 am
Forum: Experimental Details
Topic: picking a trial
Replies: 3
Views: 116

Re: picking a trial

It doesnt really matter but you can make calculations a little bit easier by choosing trials with simpler numbers.
by MariahClark 2F
Sun Mar 17, 2019 12:02 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: galvanic cells
Replies: 6
Views: 152

Re: galvanic cells

Pretty sure porous disk is just a single line and the salt bridge is a double line.
by MariahClark 2F
Sat Mar 16, 2019 11:57 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6N1 b) 7th edition
Replies: 1
Views: 100

Re: 6N1 b) 7th edition

It could be an error in the solutions? I did the problem and its definitely 1e.
by MariahClark 2F
Sat Mar 16, 2019 11:47 pm
Forum: Balancing Redox Reactions
Topic: 6L 3D (7th Edition)
Replies: 1
Views: 71

Re: 6L 3D (7th Edition)

The easy way is to just remember that the right side of the electrode is the site of reduction and the left side is the site of oxidation. Is this what you were referring to?
by MariahClark 2F
Sat Mar 16, 2019 11:09 pm
Forum: First Order Reactions
Topic: Graphs/Plots
Replies: 2
Views: 109

Re: Graphs/Plots

I dont think so to be honest, those are the main portions that tell you anything about the reaction.
by MariahClark 2F
Sat Mar 16, 2019 10:53 pm
Forum: Balancing Redox Reactions
Topic: Oxidation Numbers
Replies: 1
Views: 98

Re: Oxidation Numbers

It is helpful to memorize the oxidation numbers for common elements like for oxygen and hydrogen. So for example, in MnO4 minus; oxygen's oxidation number is -2. There are 4 oxygens which totals up to a -8. A +8 would be needed to balance out the compound but since the compound is -1, Mn's oxidation...
by MariahClark 2F
Sat Mar 16, 2019 10:48 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: adiabatic systems
Replies: 7
Views: 171

Re: adiabatic systems

It means that there it no additional heat being transferred between or within the system. There could already be heat in there to begin with but it will not change.
by MariahClark 2F
Sat Mar 16, 2019 10:35 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: equilibirum expression
Replies: 3
Views: 101

Re: equilibirum expression

You don't include solids or liquids I think. Just aqueous and gases.
by MariahClark 2F
Sun Mar 10, 2019 11:40 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.3
Replies: 1
Views: 26

Re: 6L.3

The second set you listed are the actual half reactions.
by MariahClark 2F
Sun Mar 10, 2019 11:14 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Units of k
Replies: 7
Views: 150

Re: Units of k

I was having trouble explaining out the equation and what makes the units different but I found a great explanation online that outlines it nicely. The rate of a chemical reaction r (or c t^-1) is given by: r = k [A]^a x [B]^b where k is the rate constant, A and B are the concentrations of the two r...
by MariahClark 2F
Sun Mar 10, 2019 11:08 pm
Forum: Second Order Reactions
Topic: Zero, First, Second Reactions
Replies: 2
Views: 46

Re: Zero, First, Second Reactions

The zero order reaction means that the rate of the reaction does not depend upon the concentration of the reactant. When the rate of the reaction depends on the first power of the reactant concentration in the rate equation, then the reaction is said to follow first order. When the rate of the react...
by MariahClark 2F
Sun Mar 03, 2019 11:59 pm
Forum: Zero Order Reactions
Topic: Order distinction
Replies: 9
Views: 156

Re: Order distinction

The rate equation can help you determine the order of the reaction. It shows the increase or decrease of a particular substance with respect to time. Or you can just add together the total order numbers of each reactant.
by MariahClark 2F
Sun Mar 03, 2019 11:51 pm
Forum: General Rate Laws
Topic: Edition 6 15.37
Replies: 1
Views: 20

Re: Edition 6 15.37

To start, for a first order reaction:
T_1/2= (0.693/K), so all you really have to do is substitute in for K.
by MariahClark 2F
Sun Mar 03, 2019 11:42 pm
Forum: General Rate Laws
Topic: Average rate of products and reactants
Replies: 1
Views: 29

Re: Average rate of products and reactants

I believe so, unless you came onto a reaction where product was being formed and the reactant concentration was not changing, which I dont believe could happen.
by MariahClark 2F
Sun Mar 03, 2019 11:36 pm
Forum: General Rate Laws
Topic: rate laws
Replies: 1
Views: 28

Re: rate laws

I mean catalysts definitely affect the rate by changing the reaction mechanism when, in case, it is actually present. So I believe it is included when it is present and not included when it is not. But from further reading I've seen that it is included in the rate constant when the constant is actua...
by MariahClark 2F
Fri Feb 01, 2019 4:10 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Enthalpy
Replies: 3
Views: 71

Re: Enthalpy

At constant pressure, the heat of reaction is equal to the enthalpy change of the system. Most chemical reactions occur at constant pressure, so enthalpy is more often used to measure heats of reaction than internal energy.
by MariahClark 2F
Fri Feb 01, 2019 3:52 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Final Temperature at Constant Pressure, and then at Constant Volume
Replies: 2
Views: 96

Final Temperature at Constant Pressure, and then at Constant Volume

Hey guys, I am working on problem 4C.3, which asks to calculate the final temperature and the change in enthalpy when 765 J of energy is transferred as heat to 0.820 mol Kr (g) at 298 L and 1.00 atm. I know how to calculate the final temperature and enthalpy with this information but I am unsure of ...
by MariahClark 2F
Tue Jun 12, 2018 4:27 pm
Forum: Conjugate Acids & Bases
Topic: Acids and Bases
Replies: 2
Views: 183

Re: Acids and Bases

Yes you can split (dissociate) weak acids and bases; however, since they are weak they just wont dissociate completely like strong acids or bases do. They will partially dissociate.
by MariahClark 2F
Sun Jun 03, 2018 10:57 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Radical
Replies: 4
Views: 113

Re: Radical

I think since there is an unpaired electron, the half-filled lone-pair orbital would demand less space. So if it demands less space than a full one then the bond angle would open up slightly. Someone correct me if I am off please haha. An example of this would be NO2
by MariahClark 2F
Sun Jun 03, 2018 10:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Confusion about lone pair placement
Replies: 2
Views: 104

Re: Confusion about lone pair placement

Are you talking about when trying to determine shape? If so I believe it usually appears on the central atom. At least that is what I have seen in most examples. So like if you are drawing VSEPR for SF(4), there would be two 90 degree lone pair bonding pair repulsions pushing the other fluorines awa...
by MariahClark 2F
Sun Jun 03, 2018 10:44 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Pi/Sigma bonds clarification
Replies: 4
Views: 106

Re: Pi/Sigma bonds clarification

The sigma bond is more just like your basic head on covalent bond, where the bond is in line with the bonding orbitals. The pi bond is a covalent bond perpendicular to the bond direction, which is usually in p-orbitals never s. This is why you wouldn't be able to rotate a double or triple bond aroun...
by MariahClark 2F
Sun May 27, 2018 9:53 pm
Forum: Resonance Structures
Topic: Contributing to Resonance Structures
Replies: 4
Views: 240

Contributing to Resonance Structures

What more makes a molecule contribute to a resonance structure other than just moving around the double or triple bonds in different place, because that is usually what I resort to. Is there more of a method to this? I've never quite fully understood.
by MariahClark 2F
Sun May 27, 2018 9:45 pm
Forum: Lewis Structures
Topic: bonds
Replies: 2
Views: 94

Re: bonds

To answer your first question, there's a lot of math involved for the technical answer but if the dissociation energy is higher then the bond is shorter, and vice versa. For the second question, they want to be as far apart from each other because the regions with negative electrical charge will rep...
by MariahClark 2F
Sun May 27, 2018 9:36 pm
Forum: Resonance Structures
Topic: Radicals
Replies: 3
Views: 170

Re: Radicals

A radical is when you count the number of valence electrons and there is an odd number, resulting in an unpaired electron. They are important because they influence the reactivity of a molecule.
by MariahClark 2F
Sun May 27, 2018 9:30 pm
Forum: Ionic & Covalent Bonds
Topic: Partial charge or full charge
Replies: 4
Views: 403

Re: Partial charge or full charge

Its easier to spot a partial charge in a covalent too when the electronegativities between the two atoms are more different. When they are about the same or closer to being the same then the electrons are more equally shared and it can be less noticeable per say.
by MariahClark 2F
Sun May 13, 2018 9:38 pm
Forum: Lewis Structures
Topic: Octet rule
Replies: 1
Views: 57

Re: Octet rule

Here are common violations to the octet rule: 1. There are a few stable compounds that have an odd number of electrons in their valence shell, which forces at least one atom in the compound to violate the octet rule. An example is NO, where the N has 7 valence electrons and O has a full 8. 2. There ...
by MariahClark 2F
Sun May 13, 2018 9:20 pm
Forum: Sigma & Pi Bonds
Topic: Sigma Bonds
Replies: 5
Views: 222

Sigma Bonds

I was looking up stuff about sigma and pi bonds because I couldn't be in class on Friday and this site said, "Note that sigma bond has been referred to as the strongest type of covalent bond because the extent of overlap is maximum in case of orbitals involved in the formation of the sigma bond...
by MariahClark 2F
Sun May 13, 2018 9:01 pm
Forum: Lewis Structures
Topic: Meaning of chemical bond
Replies: 5
Views: 112

Re: Meaning of chemical bond

Well, it depends on what bond you are referring to. In a covalent bond, the electrons are shared between the atoms. If the bond is an ionic, then an atom basically takes or borrows (whichever way you see it) an electron or multiple from another atom.
by MariahClark 2F
Sun May 06, 2018 8:01 pm
Forum: Trends in The Periodic Table
Topic: Electron Affinity
Replies: 3
Views: 146

Re: Electron Affinity

An easy way to think about electron affinity is the amount of energy required to [censored] an electron from a specific atom. This can also be thought of as how strong an atom's pull on its electrons are. If an atom has a high electron affinity, it would not be easy to pull off one of its electrons.
by MariahClark 2F
Sun May 06, 2018 6:44 pm
Forum: Trends in The Periodic Table
Topic: electronegativity
Replies: 4
Views: 129

Re: electronegativity

Electronegativity describes an atom's tendency to attract bonding pair electrons to itself, which can be determined mainly by the number of valence electrons in the outer shell. In theory, an atom wants 8 outer valence electrons to feel completely stable... so to satisfy that it will pull from other...
by MariahClark 2F
Sun May 06, 2018 5:58 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: electron configuration of chromium? [ENDORSED]
Replies: 3
Views: 176

Re: electron configuration of chromium? [ENDORSED]

The way I know Cr's electron configuration to be is: [Ar] 3d^5 4s^1... this is still different from the regular way we would find electron configuration for it, which is [Ar] 3d^4 4s^2 and it is one of the exceptions. In order for Cr to be more stable it would rather have its d and s energy level be...
by MariahClark 2F
Sun Apr 29, 2018 11:54 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Short hand for test
Replies: 2
Views: 66

Re: Short hand for test

I asked a question like that in class and Lavelle made it clear that shorthand could be used and it is indeed the closest noble gas. Im sure if he wanted the longer more detailed version he would specifically say on the test.
by MariahClark 2F
Sun Apr 29, 2018 11:50 pm
Forum: Trends in The Periodic Table
Topic: atomic radius
Replies: 4
Views: 123

Re: atomic radius

Im not quite sure if we will be asked to calculate the atomic radius ever but I think its worth knowing how to get a generalization with a periodic trend. In general, the size of an atom will decrease when you go from left to right on the periodic table but will increase as you go down a certain gro...
by MariahClark 2F
Sun Apr 29, 2018 11:44 pm
Forum: Trends in The Periodic Table
Topic: ionization energy
Replies: 3
Views: 98

Re: ionization energy

Atomic number, which correlates with atomic mass increases from left to right, top to bottom. Ionization energy increases from left to right, bottom to top. Hope this helps.
by MariahClark 2F
Sun Apr 29, 2018 11:44 pm
Forum: Trends in The Periodic Table
Topic: ionization energy
Replies: 3
Views: 98

Re: ionization energy

Atomic number, which correlates with atomic mass increases from left to right, top to bottom. Ionization energy increases from left to right, bottom to top. Hope this helps.
by MariahClark 2F
Sun Apr 29, 2018 11:33 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Pd electron configuration
Replies: 2
Views: 256

Re: Pd electron configuration

I looked up why that would be the case I sometimes dont understand how that d level works the way it does. What I found out was that full d orbitals are more stable than partially filled ones and that at higher energy levels are said to be degenerated. That means that the energy levels I guess are c...
by MariahClark 2F
Sun Apr 29, 2018 11:27 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron's Spin
Replies: 3
Views: 80

Re: Electron's Spin

So, the way it was discovered was shooting a beam of the e- through a passageway of two magnets, one north pole and one south pole. When the electrons went through they would either pull upwards or pull downwards, indicating that there was a type of spinning involved; Hopefully that answers your que...
by MariahClark 2F
Sun Apr 22, 2018 11:56 pm
Forum: Properties of Electrons
Topic: Heisenburg Indeterminancy Equation
Replies: 1
Views: 143

Re: Heisenburg Indeterminancy Equation

I just now realized this is in the wrong forum but the question still stands haha.
by MariahClark 2F
Sun Apr 22, 2018 11:53 pm
Forum: Properties of Electrons
Topic: Heisenburg Indeterminancy Equation
Replies: 1
Views: 143

Heisenburg Indeterminancy Equation

In class I was having trouble understanding the image Lavelle drew on the board to explain what the Heisenberg indeterminacy equation determines, can someone explain how the model worked because I am still lost on it. Also is the indeterminacy equation only good for showing the uncertainty of a spec...
by MariahClark 2F
Sun Apr 22, 2018 11:37 pm
Forum: Properties of Light
Topic: Test 2 Material
Replies: 12
Views: 373

Re: Test 2 Material

I believe it is new material... Lavelle sent out an email with the specific questions that Test 2 will cover.
by MariahClark 2F
Sun Apr 22, 2018 11:35 pm
Forum: Properties of Light
Topic: Amplitude and Intensity
Replies: 6
Views: 202

Re: Amplitude and Intensity

Light and intensity are not the same, although light can have varying intensities. Light consists of photons while intensity is simply a measurement. When measuring the intensity of light, it is specifically the amount of photons being emitted per unit of time. To use it in a situation is that even ...
by MariahClark 2F
Sun Apr 15, 2018 11:59 pm
Forum: Properties of Light
Topic: plancks constant
Replies: 2
Views: 61

Re: plancks constant

It relates the energy of one photon of electromagnetic radiation to the frequency of that radiation.
by MariahClark 2F
Sun Apr 15, 2018 11:58 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg formula
Replies: 1
Views: 47

Re: Rydberg formula

The Rydberg formula is used to predict the wavelength of light from when an electron is moving in between different energy levels of an atom. This is the formula: 1/λ = RZ2(1/n12 - 1/n22). Youll have to look up what the formula looks like because I cant paste it to look correctly haha.
by MariahClark 2F
Sun Apr 15, 2018 11:54 pm
Forum: Properties of Light
Topic: Wave particle duality
Replies: 3
Views: 57

Re: Wave particle duality

From all the sources that I looked up, because I thought your question was interesting, I think constructive and destructive interference only happens between two waves because you only add or subtract the amplitudes of two waves. I never saw anyone talk about how to do that with more than two waves...
by MariahClark 2F
Sun Apr 15, 2018 11:41 pm
Forum: Properties of Light
Topic: Amplitude
Replies: 3
Views: 68

Re: Amplitude

What do you mean by "will cause in an increase in effect"?

Go to advanced search