Search found 42 matches
- Thu Feb 22, 2018 4:21 pm
- Forum: Balancing Redox Reactions
- Topic: 14.13
- Replies: 1
- Views: 115
Re: 14.13
I'm pretty sure both ways are right especially if you got the right overall balanced reaction. The only way that it would definitely be Au(s) is if the table of reactions shows this reaction of having Au as a solid and aqueous product.
- Thu Feb 22, 2018 4:16 pm
- Forum: Balancing Redox Reactions
- Topic: Balancing H+
- Replies: 4
- Views: 304
Re: Balancing H+
Yes both are correct the difference is that H+ is the older way of writing the reaction and H3O+ is the new way. I don't think you will be penalized for using either or as long as you balance them correctly.
- Thu Feb 22, 2018 4:10 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation
- Replies: 3
- Views: 277
Re: Oxidation
By seeing the change in charges from the reactants to products side. If there is a gain of electrons for a molecule the product is reduced and if there is a loss of electrons the product is oxidized.
- Thu Feb 15, 2018 4:40 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: system vs surroundings
- Replies: 6
- Views: 493
Re: system vs surroundings
The only system is where the reaction occurs where as everything else in the universe is the surrounding which includes (both the beaker and the atmosphere).
- Thu Feb 15, 2018 4:38 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Cell potential
- Replies: 2
- Views: 1624
Re: Cell potential
In addition to Naomi's post if E°cell > 0, then the process is spontaneous but if E°cell < 0, then the process is non-spontaneous.
- Thu Feb 15, 2018 4:36 pm
- Forum: Balancing Redox Reactions
- Topic: Splitting Redox Reactions
- Replies: 3
- Views: 290
Splitting Redox Reactions
How do you know where to split the reaction into half reactions? I know that a part is oxidized and the other is reduced but what about the other molecules that don't change signs?
- Fri Feb 09, 2018 9:06 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Second Law of Thermodynamics [ENDORSED]
- Replies: 5
- Views: 524
Re: Second Law of Thermodynamics [ENDORSED]
It is true that human bodies are highly ordered but we give of heat, the food we consume becomes energy or becomes waste, your cells are constantly dying and multiplying which are all properties that increase the disorder in the world. An example that would help with the disorder aspect of humans is...
- Fri Feb 09, 2018 9:01 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: test question 5
- Replies: 5
- Views: 399
Re: test question 5
I think that part of it is that the cooler is most likely an electric one that works like a fridge rather than a styrofoam cooler which is more likely to be affected by the temperature of the environment.
- Fri Feb 09, 2018 8:59 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Isolated
- Replies: 9
- Views: 600
Re: Isolated
The isolated system is able to have reactions occur within its walls. It does not however allow for the environment to play a role as in the exchange of energy or matter by/to the system to the environment. It works like a hydro flask with ice, after many hours the ice will melt and there would be a...
- Fri Feb 02, 2018 10:23 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Reversible Processes
- Replies: 1
- Views: 157
Re: Reversible Processes
There can be more than one factor that isn't constant but then you'll have to combine other formulas like it would be a multi-step solution. A reversible process has the same entropy regardless if the reaction is favoring the reactants or products.
- Fri Feb 02, 2018 10:04 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: entropy
- Replies: 4
- Views: 270
Re: entropy
Lavelle compared temperature and entropy with sneezing in a library (low noise=temperature) vs. sneezing in a busy bus station (loud noise=high temperature). The noise caused by a sneeze would cause more of a reaction in a library than a noisy place the same way entropy is more affected by low tempe...
- Fri Feb 02, 2018 9:57 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Residual Molar Entropy?
- Replies: 3
- Views: 240
Re: Residual Molar Entropy?
There are 6 different possible configurations for SO2F2 so the degeneracy (W) is equal to 6.
So all you have to do is make S=kln[6^(6.02x10^-23)] with k being Boltzmann's constant.
So all you have to do is make S=kln[6^(6.02x10^-23)] with k being Boltzmann's constant.
- Thu Jan 25, 2018 8:39 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: HW 8.99
- Replies: 2
- Views: 257
Re: HW 8.99
By finding the limiting regent you can calculate the energy released by the reaction and therefore find temperature
- Thu Jan 25, 2018 8:35 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Gibbs Free Energy and Maximum Non-Expansion Work
- Replies: 1
- Views: 1184
Gibbs Free Energy and Maximum Non-Expansion Work
How can I calculate the maximum nonexpansion work by using Gibbs Free Energy?
- Thu Jan 25, 2018 8:33 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Entropy of an Ideal Gas
- Replies: 2
- Views: 210
Entropy of an Ideal Gas
How is the entropy of an ideal gas related to its volume in an isothermal expansion?
- Mon Jan 15, 2018 10:06 pm
- Forum: Phase Changes & Related Calculations
- Topic: Problem 8.29
- Replies: 4
- Views: 266
Re: Problem 8.29
In the textbook in section 8.10 there is a chart comparing linear and bent molecules with their molar heat capacities. "The molar heat capacity of NONlinear molecules is HIGHER than linear molecules because they can rotate about 3 rather than 2 axes." If you were to draw the lewis structur...
- Mon Jan 15, 2018 9:53 pm
- Forum: Phase Changes & Related Calculations
- Topic: Types of Systems
- Replies: 10
- Views: 869
Re: Types of Systems
A closed system is able to interact with its surroundings and exchange energy such as heat. However, an isolated system is completely independent and doesn't interact with its surroundings.
- Mon Jan 15, 2018 9:50 pm
- Forum: Phase Changes & Related Calculations
- Topic: Expansion Work
- Replies: 1
- Views: 187
Re: Expansion Work
Expansion work relates to pressure-volume work and is found with the equation w=-Pext*dV . Nonexpansion work deals with electricity and other forces such as friction and motion, and the maximum amount of nonexpansion work that can occur is given by Gibbs free energy.
- Wed Jan 10, 2018 3:45 pm
- Forum: Phase Changes & Related Calculations
- Topic: Energy and Phase Changes
- Replies: 5
- Views: 360
Re: Energy and Phase Changes
Heat=Energy so the heat being applied is being used to break the bonds between water molecules instead of to heat up the water. The Max temperature (boiling point) of water is 100 degrees so after the liquid water reaches this point the added heat is used as energy to break the bonds. Ice is less de...
- Wed Jan 10, 2018 3:38 pm
- Forum: Phase Changes & Related Calculations
- Topic: Endo and Exothermic Ways to Remember
- Replies: 28
- Views: 6117
Re: Endo and Exothermic Ways to Remember
Endo sounds like into so heat moving into it vs. exo which sounds like exit which means the heat is being moved out of whatever it may be.
- Wed Jan 10, 2018 3:36 pm
- Forum: Phase Changes & Related Calculations
- Topic: Enthalpy of Freezing
- Replies: 4
- Views: 585
Re: Enthalpy of Freezing
I think its the same symbol for both freezing and melting which is ∆Hfus. It's just freezing is from liquid to solid so the value is negative because the reaction is exothermic (-∆Hfus) where as melting is endothermic (+∆Hfus).
- Fri Dec 08, 2017 10:31 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Valence electrons [ENDORSED]
- Replies: 7
- Views: 664
Re: Valence electrons [ENDORSED]
The 2s electrons can be taken from the atom which would leave the other electrons from different orbitals behind, therefore shielding them from other electronegative atoms.
- Fri Dec 08, 2017 10:24 pm
- Forum: *Titrations & Titration Calculations
- Topic: ICE Box: How to find the equation to plug into the Quadratic Formula
- Replies: 2
- Views: 673
Re: ICE Box: How to find the equation to plug into the Quadratic Formula
When it comes to an equation what has the coefficient to do with the reaction? Like when figuring out when equilibrium is achieved?
- Wed Dec 06, 2017 12:52 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Cancelled Class [ENDORSED]
- Replies: 1
- Views: 220
Cancelled Class [ENDORSED]
Are we learning the material that we were supposed to cover today on Friday or will it not be in the Final?
- Sat Dec 02, 2017 2:29 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Monodentate vs Bidentate etc. [ENDORSED]
- Replies: 7
- Views: 3206
Re: Monodentate vs Bidentate etc. [ENDORSED]
Monodentate can be translated as "one tooth," referring to the ligand binding to the center through only one atom. Bidentate ligands have two donor atoms which allow them to bind to a central metal atom or ion at two points. Polydentate ligands range in the number of atoms used to bond to ...
- Sat Dec 02, 2017 12:35 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kc [ENDORSED]
- Replies: 3
- Views: 236
Kc [ENDORSED]
How does temperature affect Kc?
- Sat Nov 25, 2017 8:54 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Temperature and K [ENDORSED]
- Replies: 3
- Views: 271
Re: Temperature and K [ENDORSED]
A temperature change occurs when temperature is increased or decreased. This shifts chemical equilibria toward the products or reactants. In exothermic reactions, increase in temperature decreases the equilibrium constant, K, whereas, in endothermic reactions, increase in temperature increases the K...
- Sat Nov 25, 2017 8:51 pm
- Forum: Dipole Moments
- Topic: Dipole Moments
- Replies: 3
- Views: 262
Re: Dipole Moments
Dipole moments relate to the separation of the ends of the molecule and the magnitude of the charges. And you shouldn't have to draw them unless you are asked to or to make a concept clearer.
Re: TM naming
There are two naming conventions: Ex. the older naming convention would use "cyano" and the newest IUPAC naming rules use "cyanido." You should be familiar with both and both will be acceptable on any exams.
- Sun Nov 19, 2017 4:15 pm
- Forum: Naming
- Topic: Terminology
- Replies: 4
- Views: 280
Re: Terminology
Is the bonding of a ligand an effort of the atom to have a complete octet? If so why are the roman numbers used?
- Sun Nov 12, 2017 4:30 pm
- Forum: Properties of Light
- Topic: Velocity [ENDORSED]
- Replies: 13
- Views: 1015
Re: Velocity [ENDORSED]
Speed and velocity are pretty much equals except that the speed doesn't tell you the direction the person/object is moving in relatively to the starting point x=0. For example a car can be traveling at a speed of 40 miles per hour but that doesn't tell you whether the car is heading west or east. Th...
- Sun Nov 12, 2017 4:22 pm
- Forum: Hybridization
- Topic: Exceptions to Electron Orbitals
- Replies: 3
- Views: 1566
Re: Exceptions to Electron Orbitals
Atoms would rather have half filled shells then a fully filled one a partially filled one, this increases stability in the atoms such as in the case of Copper and Chromium.
- Fri Nov 03, 2017 3:39 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Electron Spin Quantum Number [ENDORSED]
- Replies: 12
- Views: 3106
Re: Electron Spin Quantum Number [ENDORSED]
The spin quantum numbers can only be 1/2 or -1/2.
- Fri Nov 03, 2017 3:36 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Midterm
- Replies: 8
- Views: 588
Re: Midterm
Nope, you're good! It's just chapters 1-3 and the fundamentals.
- Wed Oct 25, 2017 9:25 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic Bonds
- Replies: 3
- Views: 368
Re: Ionic Bonds
If an atom has less than 4 valence electrons they will typically lose their electrons to become like a Nobel gas. If an atom has more than 4 valence electrons they will typically gain their electrons to achieve the same octet state. When it comes to the ones that have exactly 4 valence electrons it ...
- Wed Oct 25, 2017 9:21 pm
- Forum: Lewis Structures
- Topic: Lewis Dot Structure
- Replies: 2
- Views: 180
Lewis Dot Structure
I know that in class the professor said that it didn't matter where you started drawing the dots but are the dots like orbitals where you have to spread out the dots like the arrows before you pair up the electrons on one side?
- Fri Oct 20, 2017 9:20 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: s-,p-, d-, and f- orbitals
- Replies: 7
- Views: 509
Re: s-,p-, d-, and f- orbitals
Yes, you can figure out how many electrons are in an atom by the orbitals. Each separate orbital can hold a max of 2 electrons.
- Fri Oct 20, 2017 9:15 pm
- Forum: Properties of Light
- Topic: Color of visible light
- Replies: 11
- Views: 817
Re: Color of visible light
No, all you have to know is that violet is about 400 nm and red is 700 nm. From this you can infer from ROY G BIV that Green would be about 550 nm since it's in the middle.
- Mon Oct 09, 2017 9:31 pm
- Forum: Properties of Light
- Topic: Experimental Value vs. Empirical Value
- Replies: 1
- Views: 188
Experimental Value vs. Empirical Value
On page 10 the experimental value of the constant is 5.67 X 10^-8 W X m^-2 X K^-4. Later on it restates the word constant for Wien's law but shows the constant as an empirical value that equals 2.9 K X mm. Is it safe to say that the Experimental value and the Empirical value are one in the same and ...
- Mon Oct 09, 2017 9:22 pm
- Forum: Properties of Light
- Topic: Transparency [ENDORSED]
- Replies: 2
- Views: 345
Re: Transparency [ENDORSED]
The way we see color is that the material/object is able to absorb all the different color wavelengths except the color that we see which is reflected off of the material. Ex. a red shirt absorbs orange-violet wavelengths but reflects the red wavelength which permits us to see the shirt as red. Surf...
- Sun Oct 08, 2017 11:45 am
- Forum: Balancing Chemical Reactions
- Topic: Percent yield [ENDORSED]
- Replies: 6
- Views: 717
Re: Percent yield [ENDORSED]
In most cases even though the difference is small there is still a difference, so you shouldn't assume that the theoretical and actual yield are the same unless it's stated otherwise. If anything this proves that your experiment was highly precise.
- Sun Oct 08, 2017 11:38 am
- Forum: Balancing Chemical Reactions
- Topic: H1 // Book Problem [ENDORSED]
- Replies: 7
- Views: 574
Re: H1 // Book Problem [ENDORSED]
If you were to add another O as a product the whole equation and the chemical reaction it expresses would be completely altered. The use of a new O would show a creation of new matter that wasn't a part of the reaction. Rather all you have to do is balance the equation to 2Cu+ SO2 ---> 2CuO+S.