Search found 80 matches
- Sat Mar 14, 2020 4:35 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: determining a catalyst
- Replies: 5
- Views: 377
Re: determining a catalyst
It is also important to distinguish between a catalyst and an intermediate in that one (the catalyst) is consumed by a step but regenerated by a later step; the other (intermediate) is created by a step but consumed by a later step.
- Sat Mar 14, 2020 4:32 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Calculating K
- Replies: 4
- Views: 506
Calculating K
When given values for standard enthalpy of reaction and value for K at one temperature, how do you find the K at another temperature (assuming that the standard enthalpy and entropy of the reaction stay constant over this temperature change)
- Sat Mar 14, 2020 4:28 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Electrode Mass
- Replies: 10
- Views: 4600
Electrode Mass
Can someone explain the effect of changing the mass of the electrode on the cell potential?
- Sat Mar 14, 2020 4:24 pm
- Forum: General Rate Laws
- Topic: Initial Rate
- Replies: 5
- Views: 458
Initial Rate
When finding the initial rate or initial concentrations, is it possible that there'll be a case where you won't have constant initial concentrations to figure out each of the order of reactants? I think I came across this scenario once, so how would you approach the problem? This applies to problems...
- Sat Mar 14, 2020 4:14 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Arrhenius Equation "A"
- Replies: 3
- Views: 316
Re: Arrhenius Equation "A"
Yeah, A in the equation is the frequency factor or pre-exponential factor, which also includes # of collisions with the correct orientation!
- Thu Mar 05, 2020 8:01 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: max work and cell potential
- Replies: 3
- Views: 268
Re: max work and cell potential
The maximum work is done under conditions of constant T &P so Gibbs free energy, which is the amount of energy that is free to do work, is the same as maximum work. The equation for Gibbs free energy=-nFE so we see the same equation for max work.
- Thu Mar 05, 2020 7:52 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Temperature
- Replies: 2
- Views: 227
Re: Temperature
temperature and rate constant have a directly proportional relationship. When t2>T1, the right-side is +, so ln of the ratio of the two constants is +, which means that k2>K1. This makes sense conceptually too because increasing temperature increases the speed of molecules which increases the chance...
- Thu Mar 05, 2020 7:48 pm
- Forum: General Science Questions
- Topic: Reducing Math Errors
- Replies: 7
- Views: 680
Re: Reducing Math Errors
before you write down ur values, just doublecheck the numbers that appear and make sure you're writing the same number and right decimal points. Also, despite the sig figs needed for the end value, it's best not to use this to write down numbers during the actual calculation process.
- Thu Mar 05, 2020 7:45 pm
- Forum: Balancing Redox Reactions
- Topic: Values of Andode and Cathode
- Replies: 8
- Views: 599
Re: Values
value of what? If you are referring to the standard reduction potential of the anode and cathode, then yes.
- Thu Mar 05, 2020 7:44 pm
- Forum: Balancing Redox Reactions
- Topic: Strength of Reducing/Oxidizing Agents
- Replies: 4
- Views: 354
Re: Strength of Reducing/Oxidizing Agents
Adding on to that, the higher to the top of the electrochemical series, the more favorable the rxtn is for reduction. Conversely, the bottom of the list favors oxidation (giving away electron).
- Sun Mar 01, 2020 2:03 pm
- Forum: General Rate Laws
- Topic: Integrated Rate Law
- Replies: 5
- Views: 381
Integrated Rate Law
What is the significance of changing a differential rate law into an integrated rate law?
- Sun Mar 01, 2020 2:00 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Salt Bridge
- Replies: 10
- Views: 512
Re: Salt Bridge
The purpose of a salt bridge is to maintain a balance of charges, since the electrons are moving from one half cell to another. This allows for the continuation of electron flow.
- Sun Mar 01, 2020 1:55 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: cell diagrams: order of components in electrodes?
- Replies: 3
- Views: 279
Re: cell diagrams: order of components in electrodes?
anode left; cathode right -separate anode and cathode with a salt bridge denoted by 2 lines - separate different states with a single line but if it's the same state but different species, denote it with a comma - solids are on the outside (solid metal electrode) and if no metal in the reaction, use...
- Sun Mar 01, 2020 1:51 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Determining "n" (6L.1)
- Replies: 1
- Views: 158
Re: Determining "n" (6L.1)
Since n is the number of electrons, you would use the half reactions to determine how many electrons were lost or gained (same #) and this is your value for n.
- Sun Mar 01, 2020 1:47 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: C(gr) state
- Replies: 4
- Views: 295
Re: C(gr) state
It means Carbon in the form of solid graphite.
- Sat Feb 22, 2020 9:50 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Pt
- Replies: 7
- Views: 484
Pt
In the cell diagrams, what does "Pt(s)" mean? And how does this change how we set up the diagram or chemical reaction equations?
- Sat Feb 22, 2020 9:48 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: relationship between concentration and Ecell
- Replies: 2
- Views: 238
Re: relationship between concentration and Ecell
Changing the concentration of the reactants or products would make Ecell either > or < E°cell, and we know from the Nernst Equation that the ratio of the concentration of products and reactants (Quotient value) is considered when calculating the value for cell potential (Ecell).
- Sat Feb 22, 2020 9:45 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Relationship between Gibbs free energy and E
- Replies: 2
- Views: 219
Re: Relationship between Gibbs free energy and E
Yes, there is that equation, but this equation can also be changed to include values for R constant, temperature, and the concentration of the products and reactants. Well, based on the equation, the spontaneity of the reaction would affect E since having a negative value for delta G (spontaneous) w...
- Sat Feb 22, 2020 9:38 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: property of E
- Replies: 6
- Views: 430
Re: property of E
When the chemical reaction is multiplied by a factor, delta G and delta°G is increased by that factor, but Ecell and E°cell stays the same. This is also because cell potential is independent of the cell size.
- Sat Feb 22, 2020 9:36 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Cell Potential
- Replies: 2
- Views: 222
Re: Cell Potential
When Ecell>E°cell, you are favoring product formation. AN increase in product concentration leads to an increase in delta G. Based on the equation, an increase in delta G would yield an increase in E cell so they are directly related! As for Ecell<E°cell, you are favoring reactant formation, which t...
- Sun Feb 16, 2020 8:39 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation Number
- Replies: 2
- Views: 215
Re: Oxidation Number
There are rules in determining the oxidation numbers and here are a few: 1)The oxidation number of a free element is always 0. 2)The oxidation number of a monatomic ion equals the charge of the ion. 3) There are some elements that already have a set oxidation number unless it is present in a compoun...
- Sun Feb 16, 2020 8:35 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Irreversible isothermal expansion of gas
- Replies: 4
- Views: 281
Re: Irreversible isothermal expansion of gas
Since delta S of the system is 3.84 Joules per Kelvins (from an isothermal, reversible expansion), and if we assume that delta S of the surroundings is also 0, the total delta S is 3.84 Joules per Kelvins as well. Both delta U and w is equal to 0, so the value of q is also 0, which accounts for the ...
- Sun Feb 16, 2020 8:27 pm
- Forum: Van't Hoff Equation
- Topic: Variable Explanations
- Replies: 3
- Views: 199
Re: Variable Explanations
There is also delta S (standard), however, we can assume this value is constant and just take in values of enthalpy and temperature
- Sun Feb 16, 2020 8:24 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: S = kblnW explanation
- Replies: 4
- Views: 533
Re: S = kblnW explanation
This equation is for residual or positional entropy where you take into consideration the degeneracy value to determine the entropy value (as opposed to the other equation that takes in values for heat and temperature)
- Sun Feb 16, 2020 8:22 pm
- Forum: Van't Hoff Equation
- Topic: Equilibrium Constant
- Replies: 4
- Views: 312
Equilibrium Constant
In the equation 0=standard delta G+RTlnQ, why is the value of Q the equilibrium constant of the reaction?
- Sat Feb 08, 2020 10:51 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Delta U at Constant V/P
- Replies: 4
- Views: 225
Re: Delta U at Constant V/P
Yes, at constant volume, delta U=qv and at constant pressure, delta U=qp+w (using qp=delta H, we can rewrite it as delta U=delta H-P*deltaV.
- Sat Feb 08, 2020 10:47 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Standard enthalpies of formation
- Replies: 5
- Views: 134
Re: Standard enthalpies of formation
Yes, you would make sure the reaction is balanced first so that you can multiply the standard enthalpies of formation of each product/reactants by the corresponding stoichiometric coefficient. Then proceed with the equation where you subtract the sum of these values (reactants) from that of products.
- Fri Feb 07, 2020 8:13 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Standard Delata G Value
- Replies: 2
- Views: 186
Standard Delata G Value
When calculating the standard delta G, we can use the standard enthalpy of formation and standard molar entropy values of the reactants and products. However, are these values given to us in the question/table or do we have to compute these values separately as well?
- Fri Feb 07, 2020 8:09 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs Free Energy
- Replies: 5
- Views: 223
Gibbs Free Energy
Is there an easier way to think about the relationship of G, H, S, and temperature in the Gibbs free energy equation and how increasing/decreasing one variable will result in a positive/negative value for delta G?
- Fri Feb 07, 2020 8:07 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Larger S
- Replies: 1
- Views: 149
Larger S
For question 4G.5, how would you calculate the entropy value for the cis molecule? I still don't quite understand how to draw this out and determine the degeneracy value...
- Sat Feb 01, 2020 3:10 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Extensive/Intensive Property
- Replies: 4
- Views: 95
Extensive/Intensive Property
Why is heat capacity an extensive property and specific heat capacity an intensive property? What does this mean?
- Sat Feb 01, 2020 3:08 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat capacity
- Replies: 2
- Views: 81
Re: Heat capacity
yes, I believe heat capacity can be negative and this would indicate that when a system loses energy, its temperature increases.
- Sat Feb 01, 2020 3:04 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Energy of Systems
- Replies: 4
- Views: 285
Energy of Systems
Lavelle mentioned that there were 3 ways of changing the energy of a system, but can someone explain a little bit more about each?
- Sat Feb 01, 2020 3:00 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Enthalpy of Rxn
- Replies: 9
- Views: 435
Re: Enthalpy of Rxn
You would multiply 300kJ/mol by the 0.05 mol since we are trying to get rid of the mol unit. Keep in mind we are trying to find the enthalpy of the reaction which the units are in joules.
- Sat Feb 01, 2020 2:57 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Degeneracy
- Replies: 3
- Views: 219
Re: Degeneracy
The dog bones he had up there were representations of the various micro states that 2 atoms can be in. Degeneracy is the number of ways of achieving a given energy state, and for 2 particles, there are 4 micro states that can fulfill this (the 4 dog bones with different combos of A/B positioning).
- Sun Jan 26, 2020 1:41 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat Capacity
- Replies: 7
- Views: 400
Heat Capacity
What is the relationship between high/low heat capacity and overall transfer of energy?
- Sun Jan 26, 2020 1:39 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: State Function
- Replies: 1
- Views: 56
State Function
I still don't understand when it says that internal energy, volume, pressure, enthalpy, temp, density etc are state functions and the significance of this? Can someone explain it in the simplest terms with examples as well?
- Sun Jan 26, 2020 1:33 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Ideal Gas QUestions
- Replies: 8
- Views: 444
Re: Ideal Gas QUestions
yes, pressure and volume are inversely proportional (this is called Boyle's Law)
- Sun Jan 26, 2020 1:31 am
- Forum: Phase Changes & Related Calculations
- Topic: Hess's Law
- Replies: 3
- Views: 113
Re: Hess's Law
the two reactions can be "fused" together to yield the end reaction, where if the reactant for one reaction is the same as the product for the other reaction, they cancel each other out. Also, you can have the product of one reaction as the reactant for the second reaction to yield the fin...
- Sat Jan 25, 2020 4:12 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Decreasing volume
- Replies: 5
- Views: 202
Decreasing volume
why is it that decreasing volume (and conversely increasing pressure) and having more moles of gas on the reactant side, favors product formation? viceversa?
- Sat Jan 25, 2020 4:08 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Standard enthalpy
- Replies: 2
- Views: 55
Standard enthalpy
What is the relationship between standard reaction enthalpy and standard enthalpy of formation?
- Sat Jan 25, 2020 4:05 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bond Enthalpy
- Replies: 4
- Views: 189
Bond Enthalpy
What is bond enthalpy and why is it always a positive value?
- Sat Jan 25, 2020 4:03 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Water Properties
- Replies: 5
- Views: 367
Water Properties
In the textbook, it stated that water is amphiprotic but that this was different than being amphoteric. Can someone explain the difference between the two?
- Sat Jan 25, 2020 3:59 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: work
- Replies: 5
- Views: 322
Re: work
work=opposing force x distance moved and work(w) is usually reported in joule (J).
This equation reflects the definition of work, which is the process of achieving motion against an opposing force
This equation reflects the definition of work, which is the process of achieving motion against an opposing force
- Fri Jan 17, 2020 7:04 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Conjugate Acids/Bases
- Replies: 2
- Views: 231
Conjugate Acids/Bases
What is a conjugate acid/base and what is its relationship to the acid/base in the same reaction?
- Fri Jan 17, 2020 7:01 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Autoprotolysis
- Replies: 1
- Views: 182
Autoprotolysis
Can someone explain more thoroughly the concept, autoprotolysis? I understand that its constant of water at 25 degrees celsius is 1x10^-14 (Kw), but how do we come to this value and what does it mean?
- Fri Jan 17, 2020 6:57 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Strength of an Acid/Base
- Replies: 2
- Views: 248
Strength of an Acid/Base
What is Ka and Kb? and what is its relationship to pKa/pKb and the strength/weakness of the acid/base?
- Sat Jan 11, 2020 10:14 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Calculating K
- Replies: 5
- Views: 183
Re: Calculating K
we don't include those two states because molar concentration of a pure substance doesn't change in a reaction
- Sat Jan 11, 2020 10:12 pm
- Forum: Ideal Gases
- Topic: PV = nRT
- Replies: 16
- Views: 1982
Re: PV = nRT
P= pressure
V=volume
n=# of moles
R=gas constant
T=temperature
V=volume
n=# of moles
R=gas constant
T=temperature
- Sat Jan 11, 2020 10:08 pm
- Forum: Ideal Gases
- Topic: Q and K
- Replies: 2
- Views: 105
Re: Q and K
K is used to calculate the concentration or pressure of a species at equilibrium while Q is used to predict the direction of a non-equilibrium reaction (whether the forward or reverse reaction is favored or if Q=K, reaction is at equilibrium). The equilibrium constant (K) is the ratio of the equilib...
- Wed Dec 05, 2018 10:06 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polar or nonpolar
- Replies: 4
- Views: 405
Re: Polar or nonpolar
It doesn't really matter where the Cl atoms are located. If the other two atoms surrounding the central atom are not chlorine, the molecule will be polar.
- Wed Dec 05, 2018 10:04 pm
- Forum: Naming
- Topic: Oxidation Numbers
- Replies: 3
- Views: 360
Re: Oxidation Numbers
No, oxidation numbers can be negative,too. For example, the element Fluorine always has an oxidation number of -1.
- Wed Dec 05, 2018 10:02 pm
- Forum: Hybridization
- Topic: hybridization
- Replies: 2
- Views: 228
Re: hybridization
I believe that sp3 would be just fine.
- Thu Nov 29, 2018 12:24 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Chelate
- Replies: 6
- Views: 613
Chelate
When a ligand binds at 1 site, it is monodentate, 2 sites it is bidentate, etc, but what is a chelate and how does it differ from the other ligands? What is its significance?
- Thu Nov 29, 2018 12:20 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordination Number
- Replies: 10
- Views: 965
Coordination Number
What is the coordination number and how do you find it?
- Thu Nov 29, 2018 12:19 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligands
- Replies: 2
- Views: 350
Ligands
I have a general idea of what a ligand is, but what is its significance and how does it relate to the lewis acids/bases?
- Tue Nov 20, 2018 10:28 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: higher polarizability
- Replies: 4
- Views: 442
higher polarizability
If two ions have the same charge, why is the smaller one the one with higher polarizing power?
- Tue Nov 20, 2018 10:26 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Difference in vocabulary terms
- Replies: 1
- Views: 178
Difference in vocabulary terms
What is the different between polarizability, polarizing power, and polarization?
- Tue Nov 20, 2018 10:25 pm
- Forum: Sigma & Pi Bonds
- Topic: Pi Bond
- Replies: 1
- Views: 242
Pi Bond
A pi bond has most of its electron density between the atomic nuclei.
Why is this statement false? Also, where is most of its electron density located at then?
Why is this statement false? Also, where is most of its electron density located at then?
- Thu Nov 15, 2018 12:09 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polarity and Molecular Shape
- Replies: 1
- Views: 184
Re: Polarity and Molecular Shape
A molecular is polar if it has a partial negative charge on one side and a partial positive side on the other. The molecular shape shows the final shape of the molecule (since it accounts for the least amount of repulsion from lone pairs too). Molecules in which all of the atoms surrounding the cent...
- Thu Nov 15, 2018 12:03 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Arrangement vs Shape
- Replies: 3
- Views: 406
Re: Arrangement vs Shape
I think that when asked for the arrangement, it's asking for all single, double, triple bonds as well as lone pair electrons (Lewis Structure). For molecular shape, it may want just the positioning of the atoms without showing what kinds of bonds are attached (almost like a simple 3D drawing) and th...
- Thu Nov 15, 2018 11:58 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular shape
- Replies: 3
- Views: 375
Re: Molecular shape
The relative strength of the intermolecular forces helps determine the boiling points. Stronger intermolecular bonds require more energy to break, so substances with stronger bonds will have a higher boiling point.(vice versa) Furthermore, more branched particles have LESS surface area compared to a...
- Thu Nov 08, 2018 10:00 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Distortion and Polarization
- Replies: 3
- Views: 1348
Re: Distortion and Polarization
Polarization is the partial or complete separation of the positive and negative electric charges in a nuclear, atomic, molecular, or chemical system. The polarity depends upon the electronegativity of the bonding atoms; most electronegative atoms pull the electronic cloud towards itself. Polarizatio...
- Thu Nov 08, 2018 9:56 pm
- Forum: Dipole Moments
- Topic: dipole interaction
- Replies: 2
- Views: 236
dipole interaction
Can someone clarify for me the relationship between polarizability, dipole moments, and fluctuating electron distribution. Also, how does the dissociation energy and interaction potential energy relate to them?
- Thu Nov 08, 2018 9:48 pm
- Forum: Ionic & Covalent Bonds
- Topic: Dipole and Dipole Moments
- Replies: 2
- Views: 291
Re: Dipole and Dipole Moments
Dipole moments occur when there is a separation of charge. They can occur between two ions in an ionic bond or between atoms in a covalent bond. They also arise from differences in electronegativity, and the larger the difference in electronegativity, the larger the dipole moment.
- Thu Nov 01, 2018 4:39 pm
- Forum: Resonance Structures
- Topic: Delocalized electrons
- Replies: 2
- Views: 321
Delocalized electrons
What does it mean to have delocalized electrons or bonds?
- Thu Nov 01, 2018 4:36 pm
- Forum: Octet Exceptions
- Topic: Boron Trifluoride class example
- Replies: 3
- Views: 353
Re: Boron Trifluoride class example
It wouldn't be correct or rather very unlikely (as said by the comment above) because the boron atoms obey a sextet rule. In this compound, the boron atom only has six valence shell electrons, but the octet rule is satisfied by the fluorine atoms around it.
- Thu Nov 01, 2018 4:29 pm
- Forum: Lewis Structures
- Topic: Determining Lewis Structure
- Replies: 3
- Views: 263
Re: Determining Lewis Structure
Formal Charge of an atom indicates the gain or loss of an electron while forming covalent bonds. An easy way to understand this concept of formal charge and stability is to think about attaining the lowest formal charge for a given Lewis structure because the one with the lowest formal charges is th...
- Sat Oct 27, 2018 10:26 am
- Forum: Lewis Structures
- Topic: Drawing Lewis Structures with Charges
- Replies: 6
- Views: 878
Re: Drawing Lewis Structures with Charges
It is also important to note that when counting electrons, negative ions should have extra electrons placed in their Lewis structures and positive ions should have less electrons than the uncharged molecule. After the Lewis structure of the ion is written, place the entire structure in brackets, and...
- Sat Oct 27, 2018 10:23 am
- Forum: Trends in The Periodic Table
- Topic: Trends in the periodic table & electron configuration
- Replies: 5
- Views: 463
Re: Trends in the periodic table & electron configuration
There is definitely a relationship between trends and electron configurations. For example, as the period goes from left to right, the electron configuration changes so that more electrons are added to the levels. This reflects the increase in Ionization Energy, since IE increases going left to righ...
- Sat Oct 27, 2018 10:17 am
- Forum: Lewis Structures
- Topic: Exceptions to octet rule
- Replies: 1
- Views: 246
Re: Exceptions to octet rule
H and He are exceptions to the Octet Rule because for them, a full shell contains only 2 electrons (1s shell). Li and Be are metals, so they're likely to lose electrons, therefore becoming cations (Li+, Be2+). When this happens, they revert to the "noble gas" configuration of He, which is ...
- Thu Oct 18, 2018 12:16 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: (6 Ed) Ch. 2 #29
- Replies: 1
- Views: 106
(6 Ed) Ch. 2 #29
#29 How many electrons can have the following quantum numbers in an atom? (a) n=2, l=1 (b)n=4, l=2, m1=-2 (c)n=2 (d)n=3 l=2 m1=+1
Thought I knew how to solve this question until I came upon the magnetic quantum number in (b). Can someone please explain what the question is asking and how to start it?
Thought I knew how to solve this question until I came upon the magnetic quantum number in (b). Can someone please explain what the question is asking and how to start it?
- Thu Oct 18, 2018 12:05 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: (6 Ed) Ch.1 #13
- Replies: 2
- Views: 309
(6 Ed) Ch.1 #13
I understand how to calculate the wavelength of radiation generated by the transition of n=1 to n=2, but how do you use this value to determine the series it belongs to and the color of light that will be emitted?
- Thu Oct 18, 2018 11:59 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Electron Configurations
- Replies: 1
- Views: 123
Electron Configurations
After doing a few of Chapter 2's homework problems, I have a couple questions: 1. What is the key difference between ground state and excited state and how does this change the electron configuration of that atom? 2. How do you obtain the magnetic quantum number from quantum number l or any other va...
- Sun Oct 14, 2018 8:25 pm
- Forum: Properties of Light
- Topic: 1A.3 7th Edition Question
- Replies: 4
- Views: 460
Re: 1A.3 7th Edition Question
As the frequency decreases, the waves broaden (wavelength increases). The extent of the change is the slope of the wave; therefore, the extent of the change also decreases.
- Sun Oct 14, 2018 7:22 pm
- Forum: Properties of Light
- Topic: Problem A9
- Replies: 5
- Views: 331
Re: Problem A9
First, use the equation c=wavelength x frequency(v). Rearrange this equation so that you are looking for the value of v, so v= c/wavelength. Then, convert nm to m. We know that the SI unit for nm is 1x10^-9m, so 2.5nm will be 2.5x10^-9m. Plug in this value as well as the speed of light constant (3.0...
- Sun Oct 14, 2018 7:01 pm
- Forum: Properties of Electrons
- Topic: Energy Q
- Replies: 4
- Views: 237
Re: Energy Q
It means that energy is only available in discrete (individual and separate) and small packets called quanta.
- Wed Oct 03, 2018 11:04 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Fundamentals E3- 7th Edition
- Replies: 3
- Views: 272
Re: Fundamentals E3- 7th Edition
In the visual, you see that there are a total of 9 Gallium atoms. Divide 9 by Avogadro's constant; this is the mole amount of Gallium on that balance. Multiply this number by 70 grams/mol (molar mass of Gallium) in order to find the mass of Gallium. Your value should come out to be 1.05x10^-21 Since...
- Wed Oct 03, 2018 10:26 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Determining the mass of salute for a given concentration
- Replies: 1
- Views: 407
Re: Determining the mass of salute for a given concentration
I believe you start by first converting the mL to L because Molarity uses the units mol/L. Since the Molarity and volume is given to you, you can find the amount in moles. After finding this value, find the molar mass of the pentahydrate and multiply this value with the mole amount. This should give...
- Wed Oct 03, 2018 10:13 pm
- Forum: Empirical & Molecular Formulas
- Topic: Molar Mass: E21
- Replies: 3
- Views: 370
Re: Molar Mass: E21
To find the amount (in moles), start by calculating the molar mass of the compound and then divide the given mass by this value. In order to find the number of molecules and formula units, multiply the mole amount by Avogadro's constant.