the units for k are 1/M^(n-1)*s. n being the order of the reaction. Thus, if the reaction is first order the units are 1/s and second order 1/Ms and so on.
x-1 is just 1/x
Search found 105 matches
- Thu Mar 12, 2020 9:33 am
- Forum: General Rate Laws
- Topic: Units
- Replies: 4
- Views: 96
- Thu Mar 12, 2020 9:29 am
- Forum: First Order Reactions
- Topic: 7A7
- Replies: 3
- Views: 75
Re: 7A7
the units for k are 1/M^(n-1)*s. n being the order of the reaction. Thus, if the reaction is first order the units are 1/s and second order 1/Ms and so on.
- Thu Mar 12, 2020 9:20 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Review Powerpoint Partial pressure
- Replies: 3
- Views: 161
Review Powerpoint Partial pressure
for the problem that asks to solve for the partial pressures of each gas PCl3 + Cl2 =PCl5 .. I found the value of K=10 but was not sure how he got the ratio of 2x/x^2 . Can someone please explain this?
- Thu Mar 12, 2020 8:41 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: How do you know a cell can do work?
- Replies: 7
- Views: 111
Re: How do you know a cell can do work?
For a cell to do work there must be a difference in cell potential. The maximum work a cell can do is equal to the difference in cell potentials.
- Thu Mar 12, 2020 8:40 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Review Question #2
- Replies: 2
- Views: 120
Re: Review Question #2
Could you specify which question?
- Thu Mar 12, 2020 8:34 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Lavelle's review slides
- Replies: 3
- Views: 66
Re: Lavelle's review slides
For student A, start by writing each rate law as if it were the rate-limiting step. If the second step is the slow step, an intermediate is found in your rate law. the k in the rate law from stoichiometric coefficients corresponds with the rate constant for step two. Then, since intermediates are no...
- Wed Mar 11, 2020 8:16 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Mechanisms
- Replies: 7
- Views: 242
Re: Mechanisms
reaction mechanisms are different pathways in which a reaction can take place. Since reactions do not simply occur at once, they are broken down into steps for different reactions to take place.
- Wed Mar 11, 2020 8:14 pm
- Forum: Zero Order Reactions
- Topic: Orders
- Replies: 8
- Views: 134
Re: Orders
the total order of the reaction is the sum of the exponential coefficients. This can be determined based on graphs, a given rate law, or an integrated rate law.
- Wed Mar 11, 2020 7:09 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Temperature and Reaction Rate
- Replies: 6
- Views: 141
Re: Temperature and Reaction Rate
reaction rate increases as temperature increases, while reaction rate decreases as temperature decreases
- Wed Mar 11, 2020 7:09 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Molecularity
- Replies: 4
- Views: 112
Re: Molecularity
unimolecular would correspond with 1 molecule that initiates the reaction
bimolecular would correspond with 2 molecules colliding to start a reaction
termolecular would correspond with 3 molecules colliding
and higher molecularity is very rare
bimolecular would correspond with 2 molecules colliding to start a reaction
termolecular would correspond with 3 molecules colliding
and higher molecularity is very rare
- Wed Mar 11, 2020 7:02 pm
- Forum: Zero Order Reactions
- Topic: 7A.15A
- Replies: 3
- Views: 77
Re: 7A.15A
the ratio of the rates is one and when you change the concentrations the only exponent that will also give 1 as a result would be zero.
- Wed Mar 11, 2020 7:00 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Steady state
- Replies: 3
- Views: 66
Re: Steady state
No, Lavelle said in lecture to focus on pre-equilibrium
- Wed Mar 11, 2020 7:00 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Fast Step/Slow Step
- Replies: 7
- Views: 127
Re: Fast Step/Slow Step
If not indicated, the fast step will be in equilibrium and the slow step will not.
- Wed Mar 11, 2020 6:18 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Pre-Equilibrium Method
- Replies: 4
- Views: 139
Re: Pre-Equilibrium Method
The pre-equilibrium method assumes that the fast rate before the slow step creates a bottleneck as the product of the fast reaction will accumulate and we assume that this causes the first reaction to be in equilibrium. By using the equilibrium constant, you can use this to solve for any intermediat...
- Tue Mar 10, 2020 6:41 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Thermodynamics problem 4.58
- Replies: 2
- Views: 101
Thermodynamics problem 4.58
(a) Verify that there is no difference in the state function S for a process in which 1.00 mol of nitrogen molecules in a cylinder of volume 3.00 L at 302 K undergoes the following three steps: (i) cooling at constant volume until T 5 75.6 K; (ii) heating at constant pressure until T 5 302 K; (iii) ...
- Mon Mar 09, 2020 12:16 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Synthesis gas 4.26
- Replies: 1
- Views: 43
Synthesis gas 4.26
The problem: A certain synthesis gas is 40.0% by volume carbon monoxide, 25.0% hydrogen gas, 10.0% noncombustible gases, and the rest methane. What volume of this gas must be burned to raise the temperature of 5.5 L of water by 5 8C? Assume the gas is at 1.0 atm and 298 K and that all three gases ar...
- Mon Mar 09, 2020 10:23 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: calculating delta H for an expansion
- Replies: 3
- Views: 142
calculating delta H for an expansion
In problem 4.17, I calculated parts a-d; however do not understand how to obtain delta H for this reaction: A technician carries out the reaction 2 SO2(g) 1 O2(g) S 2 SO3(g) at 25 8C and 1.00 atm in a cylinder fitted with a piston and maintained at constant pressure. Initially, 0.030 mol SO2 and 0.0...
- Sun Mar 08, 2020 8:14 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Calculate G independent of temperature
- Replies: 1
- Views: 66
Calculate G independent of temperature
Assume H and S are independent of temperature, calculate G for each reaction at 80C. What temperature range will each reaction be spontaneous. For part a, B2O3 +6HF --> 2BF3 +3H2O when I started this problem I used the standard heat of formations for the products - reactants and the standard entropy...
- Thu Mar 05, 2020 9:22 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Standard Cell Potential and Equilibrium
- Replies: 2
- Views: 38
Re: Standard Cell Potential and Equilibrium
since Estandard=-rt/nf (lnK)
as you increase the value of K, increasing the amount of product, you increase the Estandard of the cell.
as you decrease the value of K, increase the amount of reactant, you decrease the Estandard of the cell.
as you increase the value of K, increasing the amount of product, you increase the Estandard of the cell.
as you decrease the value of K, increase the amount of reactant, you decrease the Estandard of the cell.
- Thu Mar 05, 2020 9:16 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Gibbs free energy and balancing redox reactions
- Replies: 2
- Views: 82
Re: Gibbs free energy and balancing redox reactions
Yes, you must balance each half reaction to determine n, the number of electrons transferred in the reaction.
- Thu Mar 05, 2020 9:15 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: question on 6M.5 part c
- Replies: 1
- Views: 52
Re: question on 6M.5 part c
the reduction of cr2o7 2- goes from oxidation number (6+-->3+) which is a transfer of 3 electrons, but since there are two, it would transfer 6 electrons. The coefficients of the reaction do not influence the cell potential so you would not divide the cell potential by this value. 1 electron is tran...
- Sun Mar 01, 2020 9:59 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: Neuron Potential 6.61
- Replies: 1
- Views: 40
Neuron Potential 6.61
If the concentration of K+ is 20-30x greater inside the cell than outside. What is the potential difference between the inside and the outside of the cell (due only to imbalance in K+ ions)? the reduction of K+ to K is -2.93... I am not sure how to approach this problem. I considered using Q but the...
- Sun Mar 01, 2020 8:48 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: Rust and Cathodic Protection
- Replies: 1
- Views: 57
Rust and Cathodic Protection
I don't remember going over the idea of cathodic protection and/or rust in lecture (i.e the activity series, and the factors involved in determining the best form of cathodic protection). There was 2 homework questions regarding this in section N. Are we responsible for knowing this for the test?
- Sun Mar 01, 2020 3:17 pm
- Forum: Van't Hoff Equation
- Topic: Half reactions 6L.9
- Replies: 2
- Views: 58
Half reactions 6L.9
For 6L.9 ad 6L. 10, how do you know how the reaction will take place. In other words, how do you decipher which will be reduced and which will be oxidized when given potassium permanganate and FeCL2 react in an acidic solution. Would you use the standard cell potentials to determine the reaction tha...
- Sun Mar 01, 2020 1:03 pm
- Forum: Van't Hoff Equation
- Topic: Van't Hoff equation on 5J.15
- Replies: 1
- Views: 55
Van't Hoff equation on 5J.15
The question asks you to calculate the K value at 25C and 150C. I correctly found the K value for the reaction at 25 C using equation G=-RTlnK, but am not sure how to apply the vant hoff equation at 150C.. the reaction is NH4CL -> NH3 + HCl
- Wed Feb 26, 2020 12:13 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: 13.43(a) and cell writing question
- Replies: 2
- Views: 4508
Re: 13.43(a) and cell writing question
If Q= products/reactants, wouldn't the concentration of H+ be on te denominator resulting in -1 as the pH for this problem?
- Wed Feb 26, 2020 10:46 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: K and Cell potential
- Replies: 3
- Views: 73
K and Cell potential
If K is large, can we assume there will be a positive cell potential for a reaction, and if K is less than one will this result in a negative cell potential? Not sure if this is the correct relationship between K and E.
- Wed Feb 26, 2020 9:34 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Strength of a reducing agent
- Replies: 3
- Views: 78
Strength of a reducing agent
How do we determine the relative reducing strength of a metal without any standard cell potentials?
- Sat Feb 08, 2020 11:44 am
- Forum: Calculating Work of Expansion
- Topic: Constant Volume and Pressure Values
- Replies: 8
- Views: 118
Constant Volume and Pressure Values
Do we need to know the different C values at constant pressure for monoatomic, diatomic, and polyatomic gases?
ex) monoatomic Cv=3/2R Cp= 5/2R ; Diatomic Cv= 5/2R Cp= 7/2R; Polyatomic Cv = 7/2R Cp=9/2R
ex) monoatomic Cv=3/2R Cp= 5/2R ; Diatomic Cv= 5/2R Cp= 7/2R; Polyatomic Cv = 7/2R Cp=9/2R
- Mon Feb 03, 2020 8:57 am
- Forum: Calculating Work of Expansion
- Topic: Area under the curve
- Replies: 3
- Views: 42
Re: Area under the curve
Yes, the area under the curve indicates the amount of work done on/by a system by comparing pressure time volume. In an irreversible expansion, once the final volume is achieved, the work done by the system prior to that is no longer relevant thus only using the amount of work done from the final vo...
- Mon Feb 03, 2020 8:54 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: delta V
- Replies: 4
- Views: 51
Re: delta V
In any situation indicating a closed/isolated system where there is no change in volume (unless it is under a piston)
- Fri Jan 31, 2020 3:57 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Degeneracy
- Replies: 9
- Views: 133
Re: Degeneracy
Degeneracy is a way to quantify the possible number of positions a particular species can form. In relation to entropy, it can be seen as the number of Microstates/positions that are possible for a particular system.
- Fri Jan 31, 2020 3:52 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Open vs. Closed Internal Energies
- Replies: 3
- Views: 50
Re: Open vs. Closed Internal Energies
If the system is closed a change in volume can still occur in the case of a gas doing work on a piston. In an isolated system, there would be no change in volume.
- Fri Jan 31, 2020 3:49 pm
- Forum: General Science Questions
- Topic: Increasing Entropy
- Replies: 5
- Views: 132
Re: Increasing Entropy
Extreme disorder?
- Mon Jan 20, 2020 4:56 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Sig Figs for pH/pOH
- Replies: 7
- Views: 71
Re: Sig Figs for pH/pOH
number of sig figs in a pH or pOH only count after the decimal. For pH=3.489, there would be three sig figs since there are 3 decimal place. If the question is only 1 sig fig then the pH can be reported to 1 decimal place. Hope this makes sense!
- Mon Jan 20, 2020 3:43 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: 6.23 Buffer Solutions
- Replies: 2
- Views: 48
6.23 Buffer Solutions
Not sure how to answer this problem, A buffer solution containing equal amounts of acetic acid and sodium acetate is prepared. What molar concentration of the buffer must be prepared to prevent a change in the pH by more than 0.20 after the addition of 1.00 mL of 6.00 m HCl(aq) to 100.0 mL of the bu...
- Sat Jan 18, 2020 4:03 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Fall Quarter Final
- Replies: 2
- Views: 53
Re: Fall Quarter Final
He said sometime during week 3, I assume there will be an email sent out to notify everyone.
- Sat Jan 18, 2020 4:02 pm
- Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
- Topic: Buffer questions
- Replies: 4
- Views: 132
Re: Buffer questions
6G has practice problems
- Sat Jan 18, 2020 4:01 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Different types of acids/bases
- Replies: 3
- Views: 38
Re: Different types of acids/bases
it is important to memorize the list of strong acids and Bases, since everything not on this list would be considered a weak acid or weak base.
- Sat Jan 18, 2020 4:00 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Effect of Temperature on Halogen Reaction (Homework 5J.11)
- Replies: 3
- Views: 78
Re: Effect of Temperature on Halogen Reaction (Homework 5J.11)
If a bond is being broken, energy is required thus the reaction would be endergonic
- Tue Jan 14, 2020 3:54 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Homework 5.35
- Replies: 3
- Views: 56
Re: Homework 5.35
to determine the ratio of the concentrations, record the final and initial concentrations of each gas, then determine ratio between them.
Ai=28 Af=18 f-i= 10
Bi=0 Bf=5 f-i= 5
Ci=0 Cf=10 f-i=10
the ratio of A:B:C is 2:1:2
Ai=28 Af=18 f-i= 10
Bi=0 Bf=5 f-i= 5
Ci=0 Cf=10 f-i=10
the ratio of A:B:C is 2:1:2
- Tue Jan 14, 2020 1:49 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5I.16
- Replies: 2
- Views: 40
5I.16
Difficulty understanding this problem... Would the K value be equal to the concentration of gas in products since the solid's are not included in the equation PV=nRT or the calculation of the equilibrium constant.
- Fri Jan 10, 2020 2:55 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Calculating eq constants with only one variable
- Replies: 3
- Views: 30
Re: Calculating eq constants with only one variable
You must use an ICE chart and assume that the products start with zero initially...
- Fri Jan 10, 2020 2:54 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: N2+3H2<->2NH3
- Replies: 5
- Views: 62
Re: N2+3H2<->2NH3
The reaction favors equilibrium so affecting one side will affect the other side of the reaction, and rxn will proceed to oppose/resist change.
- Fri Jan 10, 2020 2:52 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium Constant for Multiples of the Chemical Equation
- Replies: 2
- Views: 30
Re: Equilibrium Constant for Multiples of the Chemical Equation
this is due to the fact that multiplying the reaction by a value (2) would be doubling all the stoichiometric coefficients, ultimately squaring the entire K value. Thus raising the K value to any value n.
- Fri Jan 10, 2020 2:50 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Why Q would be greater than K
- Replies: 5
- Views: 39
Re: Why Q would be greater than K
Unless a change had been acted upon a system or reaction, there will be no change in equilibrium. Adding or removing P/R, affecting the concentration for both (aq) and (g) products/reactants.
- Fri Jan 10, 2020 11:10 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kp vs Kc
- Replies: 6
- Views: 42
Re: Kp vs Kc
Use KP for gases with partial pressure values and use KC for concentration gases, and aqueous conditions.
- Sat Dec 07, 2019 8:32 pm
- Forum: Identifying Acidic & Basic Salts
- Topic: 6D.11 (e) & (f)
- Replies: 2
- Views: 146
Re: 6D.11 (e) & (f)
octahedral complexes are the most common, so generally they will have 6 water molecules attached.
- Sat Dec 07, 2019 8:29 pm
- Forum: Identifying Acidic & Basic Salts
- Topic: Hw Problem 6D.11
- Replies: 4
- Views: 169
Re: Hw Problem 6D.11
you should know the strong acids and bases, so you will know that everything else would be weak.
- Sat Dec 07, 2019 12:50 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: coordination number and shape
- Replies: 1
- Views: 62
coordination number and shape
How do you determine the coordination number and shape of a coordination compound?
Why is K[Cu(en)2(CN)2]-1 coordination number 6 octahedral while [Co(OH)2C2O4]-1 is 4 square planar/tetrahedral?
Is the -1 charge playing a role in determining the + of ligands or is it the ion outside the complex?
Why is K[Cu(en)2(CN)2]-1 coordination number 6 octahedral while [Co(OH)2C2O4]-1 is 4 square planar/tetrahedral?
Is the -1 charge playing a role in determining the + of ligands or is it the ion outside the complex?
- Thu Dec 05, 2019 2:05 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: CH4 versus CCl4 (Boiling Point)
- Replies: 3
- Views: 47
Re: CH4 versus CCl4 (Boiling Point)
CCl4 is a much larger molecule, and has more electrons, so it will form more LDF's, which require more energy to break apart.
- Thu Dec 05, 2019 2:02 pm
- Forum: Air Pollution & Acid Rain
- Topic: Acid rain
- Replies: 2
- Views: 135
Re: Acid rain
Acid rain results from the reaction of H2O+CO2→ H2CO3 Increase in concentration of CO2 in the atmosphere will result in an increase of H2CO3, which is acidic forming acid rain. SO2, NO, and NO2 are also components of acid rain that form HNO3 and HSO4- (strong acids) A way to reduce this would be ins...
- Thu Dec 05, 2019 1:58 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: coordination number
- Replies: 6
- Views: 83
Re: coordination number
How does that tell you the coordination number?
- Thu Dec 05, 2019 1:56 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Weak vs Strong acids and bases
- Replies: 6
- Views: 133
Re: Weak vs Strong acids and bases
a weak base will not dissociate completely, so it won't yield as many OH- ions in the solution, and since a strong base does dissociate completely the OH- concentration is much higher in a solution with a strong base than one with a weak base.
- Thu Dec 05, 2019 1:54 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: chelate
- Replies: 3
- Views: 84
Re: chelate
Not all ring structures chelate though, make sure that the electron pairs are close together, otherwise they will only remain polydentate and will not chelate.
- Thu Dec 05, 2019 1:51 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: coordination number
- Replies: 6
- Views: 83
coordination number
How do you approach this problem? not sure of my answers... determine the coordination number of the metal ion in each of the following complexes: (a) [NiCl4]2–; (b) [Ag(NH3)2]1 ; (c) [PtCl2(en)2]21 ; (d) [Cr(edta)]2
- Tue Nov 26, 2019 7:23 pm
- Forum: Bronsted Acids & Bases
- Topic: J.17
- Replies: 2
- Views: 49
Re: J.17
the question is mostly focused on the fact that this reaction is in equilibrium and has a K constant
- Tue Nov 26, 2019 7:17 pm
- Forum: Hybridization
- Topic: s character
- Replies: 2
- Views: 40
Re: s character
More s character means that it has less electron-electron repulsion since there are less electrons in the p orbital, therefore the less repulsions would result in greater bond angle.
- Tue Nov 26, 2019 7:15 pm
- Forum: Biological Examples
- Topic: vitamin b12
- Replies: 3
- Views: 73
Re: vitamin b12
I think to know the biological context of vitamin b12 through the chelation of cobalt.
- Tue Nov 26, 2019 7:12 pm
- Forum: Hybridization
- Topic: double bonds
- Replies: 7
- Views: 126
Re: double bonds
The second bond would form as a result of an unhybridized orbital.
- Tue Nov 26, 2019 7:04 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 2
- Replies: 7
- Views: 108
Re: Test 2
I got my test back during discussion today, so I would say your next discussion section.
- Mon Nov 18, 2019 4:30 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Water attraction
- Replies: 1
- Views: 34
Water attraction
Would water attract Be2+ or Al3+ more strongly through the ion-dipole IMF?
- Mon Nov 18, 2019 4:07 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Stronger IMF's
- Replies: 2
- Views: 40
Stronger IMF's
How do you determine whether SiF4 or Si2F2 has stronger IMF's?
I know the linear structure creates stronger IMF's than trigonal planar. But would the larger number of e- in SiF4 allow for more IMF's?
I know the linear structure creates stronger IMF's than trigonal planar. But would the larger number of e- in SiF4 allow for more IMF's?
- Sat Nov 16, 2019 2:43 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Interaction Potential Energy
- Replies: 3
- Views: 57
Re: Interaction Potential Energy
This is the potential energy for the intermolecular interactions rather the ones within a molecule.
- Sat Nov 16, 2019 2:42 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Using Dipole moments to determine if a molecule is polar or non polar
- Replies: 2
- Views: 38
Re: Using Dipole moments to determine if a molecule is polar or non polar
I drew all three isomers. and since Cl is the most electronegative, it has the negative dipole in the 1,4 structure it is nonpolar since the dipoles are directly across from each other (so they cancel), but in isomer 1,3 and 1,2 the dipoles do not cancel thus they are polar.
- Sat Nov 16, 2019 2:37 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2E.19b
- Replies: 2
- Views: 35
2E.19b
How do you determine the shape of this molecule? (CH3)2Be. Not sure how to translate the ionic lewis structure into the shape since the central atom had two "branches".
- Tue Nov 12, 2019 12:16 pm
- Forum: Dipole Moments
- Topic: London forces
- Replies: 4
- Views: 57
Re: London forces
All molecules, whether they are polar or nonpolar, have London Dispersion forces. It is the only type of intermolecular force that exists between noble gases and nonpolar molecules.
- Tue Nov 12, 2019 12:13 pm
- Forum: Dipole Moments
- Topic: HW Question 3F1
- Replies: 5
- Views: 131
Re: HW Question 3F1
The polarity of so2 is due to the lone pairs on the S, which creat a bent shape. This will make more sense once we learn shape.
- Tue Nov 12, 2019 11:54 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: 2D.9
- Replies: 6
- Views: 207
Re: 2D.9
Polarizing power depends on size and charge. The smaller and higher the charge, the greater the ability to attract the electron cloud of the partial negative atom. Smaller atoms allow for less distance between atoms, so electrons can be easily distorted in a molecule, and a higher charge will allow ...
- Tue Nov 12, 2019 11:51 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Induced dipole-induced dipole interactions
- Replies: 2
- Views: 29
Re: Induced dipole-induced dipole interactions
These instantaneous "bounces" in temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles. Electron clouds of two relatively non-polar molecules have moments of attraction.
- Mon Nov 04, 2019 9:15 am
- Forum: Coordinate Covalent Bonds
- Topic: Dissociation energy
- Replies: 3
- Views: 201
Dissociation energy
Explain how covalent bond dissociation energy is related to covalent bond multiplicity, atomic radius, and the presence of unpaired electrons. Am mostly confused on the reference to the presence of unpaired electrons.
- Mon Nov 04, 2019 9:13 am
- Forum: Bond Lengths & Energies
- Topic: Factors
- Replies: 1
- Views: 39
Factors
What are the factors affecting covalent bond length and the effect of each?
- Mon Nov 04, 2019 9:12 am
- Forum: Electronegativity
- Topic: Difference
- Replies: 5
- Views: 90
Difference
What is the difference between electronegativity and polarizability?
- Mon Nov 04, 2019 9:11 am
- Forum: Lewis Structures
- Topic: Line structures
- Replies: 2
- Views: 37
Line structures
Should we be familiar with complex line structures for the midterm.. never went over it.
- Mon Nov 04, 2019 9:09 am
- Forum: Properties of Light
- Topic: General Concept
- Replies: 3
- Views: 77
General Concept
• Describe the nature of light as electromagnetic radiation (wave model) and as a stream of photons (photon model).
- Wed Oct 30, 2019 2:06 pm
- Forum: Ionic & Covalent Bonds
- Topic: 2D.9
- Replies: 1
- Views: 33
2D.9
Question: Arrange the cations Rb+, Be2+, Sr2+ in order of increasing polarizing power. I know this is based on, which is more electronegative, but don't know how to approach Rb+ and Sr2+ since they are isoelectronic.
- Sun Oct 27, 2019 4:16 pm
- Forum: Bond Lengths & Energies
- Topic: C-C bond lengths
- Replies: 4
- Views: 92
Re: C-C bond lengths
This is due to resonance. Resonance makes it so that the electrons are delocalized and the actual structure is a combination of all of the different resonant structures, which creates a "blend" or average of the bond lengths.
- Sun Oct 27, 2019 4:15 pm
- Forum: Lewis Structures
- Topic: Dots vs Lines in Lewis Structures
- Replies: 6
- Views: 121
Re: Dots vs Lines in Lewis Structures
dots normally represent lone pairs and the lines represent bonds, it is definitely important to represent bonds using the lines rather than dots to avoid confusion.
- Sun Oct 27, 2019 4:13 pm
- Forum: Trends in The Periodic Table
- Topic: 1F.17
- Replies: 1
- Views: 36
Re: 1F.17
Diagonal relationship: Some elements of certain groups in the second period resemble with the certain elements of the next higher group in the third period. This is called diagonal relationship. Thus lithium resembles magnesium (Mg), beryllium (Be) resembles aluminum (Al) and boron (B) resembles sil...
- Sun Oct 27, 2019 4:05 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Shielding
- Replies: 3
- Views: 38
Re: Electron Shielding
Basically the electrons that are closer to the nucleus (in smaller sublevels s<p<d<f) are better at shielding. For example, electrons in the s orbital are better at shielding than the p orbital since they are closer to the nucleus and experience a greater nuclear charge in addition to the fact that ...
- Sun Oct 27, 2019 4:01 pm
- Forum: Ionic & Covalent Bonds
- Topic: 2A.5
- Replies: 2
- Views: 25
Re: 2A.5
the Lanthanide series atomic number 57-70 comes before Bi3+
- Sun Oct 27, 2019 3:59 pm
- Forum: Ionic & Covalent Bonds
- Topic: 2A.5
- Replies: 2
- Views: 25
Re: 2A.5
Normally you wouldn't have to worry about this in the context of this class, but Bi3+ has 3 less electrons so the configuration from the closest noble gas, Xenon, would be [Xe]4f^14 5d^10 6s^2
- Sun Oct 27, 2019 3:57 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Where electrons are more likely to be found
- Replies: 1
- Views: 75
Re: Where electrons are more likely to be found
The nodes represent where the electrons cannot be found. It is less likely for an electron in the p orbital to be found close to the nucleus; however, it just depends on the electron-electron interactions as well as the effective nuclear charge experienced by that electron.
- Mon Oct 21, 2019 2:16 pm
- Forum: Trends in The Periodic Table
- Topic: Focus 1 Exercise 1.13
- Replies: 3
- Views: 34
Re: Focus 1 Exercise 1.13
IE for Oxygen is lower than N and F because having a half full or completely full orbital is more stable and favorable. Thus, since oxygen has 4 valence electrons, it is 1 electron too many to have a half full orbital (3 e-out of 6). Therefore, the Ionization Energy (energy to remove an electron) is...
- Mon Oct 21, 2019 2:12 pm
- Forum: Properties of Electrons
- Topic: Problem 1E.5
- Replies: 3
- Views: 114
Re: Problem 1E.5
My reasoning for this problem was: a) is false since Zeff is dependent on the # e- because the amount of shileding that can occur is affected by the number of electrons. More electrons, more shielding, lower Zeff. b) is true because the p and d orbitals are more effective at shielding since they are...
- Mon Oct 21, 2019 11:32 am
- Forum: SI Units, Unit Conversions
- Topic: Additional Practice
- Replies: 2
- Views: 149
Re: Additional Practice
Additional practice problems in the book work well for me.
- Sun Oct 20, 2019 3:42 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: 1.B.15?
- Replies: 2
- Views: 32
Re: 1.B.15?
for part A, just use the equation (velocity)=(frequency)(wavelength) for part B, the question asks about the relationship between energy and frequency so you would use E=hf for part C, then using the energy you just determined, use the equation E= (hc) /(wavelength) so solve for the wavelength. for ...
- Sun Oct 20, 2019 3:35 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: What does the H mean?
- Replies: 9
- Views: 101
Re: What does the H mean?
What exactly are you referring to? It could also mean H-atom
- Sun Oct 20, 2019 3:33 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: 1D. 25
- Replies: 4
- Views: 52
Re: 1D. 25
Its important to remember during this question where the electron is both in the orbital and the periodic table is extremely helpful in working that out.
- Mon Oct 14, 2019 9:58 pm
- Forum: Photoelectric Effect
- Topic: 29B and 30C
- Replies: 1
- Views: 87
29B and 30C
28. Light hits a sodium metal surface and the velocity of the ejected electron is 6.61 x 105 m.s-1. The work function for sodium is 150.6 kJ.mol-1. Answer the following three questions. A. What is the kinetic energy of the ejected electron? 1.99*10^-19J 29. B. How much energy is required to remove a...
- Mon Oct 14, 2019 7:31 pm
- Forum: *Shrodinger Equation
- Topic: Hamiltonian
- Replies: 5
- Views: 89
Re: Hamiltonian
It's also significant when considering the fact that the second derivative of the trig function will return to the original function (possible change of sign, but that is not important)
- Mon Oct 14, 2019 3:57 pm
- Forum: Photoelectric Effect
- Topic: frequency and speed
- Replies: 7
- Views: 115
Re: frequency and speed
If the electromagnetic radiation is light, then it can be thought of as an EM wave. So since E=hv, the energy per photon would be proportional to the frequency not necessarily the speed. Correct?
- Mon Oct 14, 2019 3:41 pm
- Forum: Photoelectric Effect
- Topic: frequency and speed
- Replies: 7
- Views: 115
Re: frequency and speed
since 1/2mv^2= hf - threshold?
- Mon Oct 14, 2019 3:41 pm
- Forum: Photoelectric Effect
- Topic: frequency and speed
- Replies: 7
- Views: 115
Re: frequency and speed
But if kinetic energy is = energy of a photon - threshold energy, then wouldn't the velocity of the photon be proportional to the frequency.
- Mon Oct 14, 2019 3:19 pm
- Forum: Photoelectric Effect
- Topic: frequency and speed
- Replies: 7
- Views: 115
frequency and speed
Why does the speed of radiation decrease when the frequency decreases?
- Wed Oct 09, 2019 12:54 pm
- Forum: SI Units, Unit Conversions
- Topic: Sig Fig Help! [ENDORSED]
- Replies: 6
- Views: 168
Re: Sig Fig Help! [ENDORSED]
The leading zeroes do not influence sig figs unless you are adding, then the decimal place is important.
- Wed Oct 09, 2019 12:53 pm
- Forum: Properties of Light
- Topic: Homework Problems
- Replies: 3
- Views: 96
Homework Problems
What Pages are the homework problems on for this chapter? having hard time figuring out which section they apply to...
- Wed Oct 09, 2019 12:47 pm
- Forum: General Science Questions
- Topic: Balancing Chemical Equations
- Replies: 5
- Views: 140
Re: Balancing Chemical Equations
In the reactants, there is an O2.
- Wed Oct 09, 2019 12:45 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Light energy
- Replies: 3
- Views: 84
Re: Light energy
You should have a pretty good idea of the visual light spectrum, but besides that I think that should be it.
- Wed Oct 09, 2019 12:44 pm
- Forum: Photoelectric Effect
- Topic: Threshold energy
- Replies: 6
- Views: 64
Re: Threshold energy
Threshold energy depends on the problem. Remember, for an electron to be emitted, a specific wavelength and energy must be reached. This is unique to every situation.