Search found 103 matches
- Wed Mar 11, 2020 7:06 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Molecularity
- Replies: 4
- Views: 418
Re: Molecularity
The molecularity of a reaction is defined as the number of molecules or ions that participate in the rate-determining step.
- Wed Mar 11, 2020 7:06 pm
- Forum: *Enzyme Kinetics
- Topic: Adsorption vs. Absorption
- Replies: 8
- Views: 1461
Re: Adsorption vs. Absorption
Absorption is the process in which a fluid is dissolved by a liquid or a solid (absorbent). Adsorption is the process in which atoms, ions or molecules from a substance (it could be gas, liquid or dissolved solid) adhere to a surface of the adsorbent.
- Wed Mar 11, 2020 7:05 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Temperature and Reaction Rate
- Replies: 6
- Views: 488
Re: Temperature and Reaction Rate
As you increase the temperature the rate of reaction increases. As a rough approximation, for many reactions happening at around room temperature, the rate of reaction doubles for every 10°C rise in temperature.
- Wed Mar 11, 2020 7:03 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Frequency Factor
- Replies: 6
- Views: 507
Re: Frequency Factor
The pre-exponential factor (A) is part of the Arrhenius equation, which was formulated by the Swedish chemist Svante Arrhenius in 1889. The pre-exponential factor is also known as the frequency factor and represents the frequency of collisions between reactant molecules. Although often described as ...
- Wed Mar 11, 2020 7:02 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: 7D.1
- Replies: 4
- Views: 340
Re: 7D.1
The equation ln(k2/k1)=-Ea/R*(1/T2-1/T1) should be able to be used.
- Fri Mar 06, 2020 3:22 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: arrhenius equation
- Replies: 1
- Views: 266
- Fri Mar 06, 2020 3:20 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 6L.9
- Replies: 2
- Views: 257
Re: 6L.9
Since both K and Cl would dissolve in the water, they wouldn't be present in the half-reactions.
- Fri Mar 06, 2020 3:16 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Question 6.65
- Replies: 2
- Views: 271
Re: Question 6.65
I think you need to use 10^-14 because that's where you would compare ph 14 and 1. If you use that in the denominator and numerator you should get +.828 and -.828, respectively.
- Fri Mar 06, 2020 3:13 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: catalyst
- Replies: 4
- Views: 432
Re: catalyst
Catalysts are present as reactants in the very beginning and products at the end. Intermediates, on the other hand, are not present in the initial reaction but are produced within one of the steps and then consumed within another step. Also, catalysts are used throughout the reaction. So according t...
- Fri Mar 06, 2020 3:12 pm
- Forum: Van't Hoff Equation
- Topic: delta G, pressure and. K
- Replies: 2
- Views: 412
Re: delta G, pressure and. K
I think this explains it well:
https://chem.libretexts.org/Bookshelves ... rown_et_al.)/19%3A_Chemical_Thermodynamics/19.7%3A_Free_Energy_and_the_Equilibrium_Constant
Essentially they are all linked through an equation.
https://chem.libretexts.org/Bookshelves ... rown_et_al.)/19%3A_Chemical_Thermodynamics/19.7%3A_Free_Energy_and_the_Equilibrium_Constant
Essentially they are all linked through an equation.
- Fri Mar 06, 2020 3:09 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 6L.3 part d
- Replies: 1
- Views: 287
Re: 6L.3 part d
I think the reason why O2 and H+ are on the same side is because the reaction would not be oxidizing if it was either
H+ -> O2 or
O2 -> H+
The equation has to be H2O -> O2 + H+ because then the reaction will be oxidizing for H in H2O -> H+
H+ -> O2 or
O2 -> H+
The equation has to be H2O -> O2 + H+ because then the reaction will be oxidizing for H in H2O -> H+
- Fri Mar 06, 2020 3:02 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Inert electrode
- Replies: 9
- Views: 605
Re: Inert electrode
Whenever the anode/cathode has no solids in its half-reaction.
- Fri Mar 06, 2020 3:01 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 6M.11
- Replies: 4
- Views: 439
Re: 6M.11
The phases are usually given in the equation. You can use those same ones in writing the cell diagram.
- Fri Mar 06, 2020 2:59 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: 6N.21
- Replies: 2
- Views: 313
Re: 6N.21
This is more of a conceptual question. The chapter itself talks about it in the last section, so we probably just have to understand the general idea.
- Fri Mar 06, 2020 2:54 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Forward and reverse reaction rates
- Replies: 4
- Views: 365
Re: Forward and reverse reaction rates
We use k vs k' to differentiate between the rates for forward and reverse reactions.
- Wed Feb 19, 2020 7:02 pm
- Forum: Van't Hoff Equation
- Topic: 5G.21
- Replies: 4
- Views: 535
5G.21
5G.21 Calculate the equilibrium constant at 25 8C for each of the following reactions, by using data in Appendix 2A: (a) the combustion of hydrogen: 2 H2(g) 1 O2(g) Δ 2 H2O(g) (b) the oxidation of carbon monoxide: 2 CO(g) 1O2(g) Δ 2 CO2(g) (c) the decomposition of limestone: CaCO3(s) Δ CaO(s) 1 CO2(...
- Tue Feb 18, 2020 7:32 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Standard Gibbs Free Energy Conditions
- Replies: 4
- Views: 393
Re: Standard Gibbs Free Energy Conditions
The standard state is 298 K or 25 degrees C.
- Tue Feb 18, 2020 7:31 pm
- Forum: Balancing Redox Reactions
- Topic: Concentration Cell
- Replies: 1
- Views: 198
Re: Concentration Cell
Concentration cells are of two types: 1. Electrode concentration cells: In these cells, the potential difference is developed between two electrodes at different concentrations dipped in the same solution of the electrolyte. For example, two hydrogen electrodes at different gaseous pressures in the ...
- Tue Feb 18, 2020 7:29 pm
- Forum: Balancing Redox Reactions
- Topic: Redox Reactions
- Replies: 2
- Views: 250
Re: Redox Reactions
An oxidizing agent is the substance that causes the oxidation in another substance. Common oxidizing agents include oxygen, hydrogen peroxide and halogens. A reducing agent is a substance that causes another substance to reduce. So to identify an oxidizing agent, simply look at the oxidation number ...
- Tue Feb 18, 2020 7:28 pm
- Forum: Van't Hoff Equation
- Topic: 5.55
- Replies: 2
- Views: 227
Re: 5.55
The standard Gibbs free energy of molecules is 0 for any element in its standard state.
- Tue Feb 18, 2020 7:26 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: reaction at equilibrium
- Replies: 6
- Views: 481
Re: reaction at equilibrium
No work is being done at equilibrium so the delta G value is 0.
- Tue Feb 18, 2020 4:51 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: delta vs. delta naught
- Replies: 3
- Views: 426
Re: delta vs. delta naught
The difference between the two is that delta G naught is at standard conditions. The reason Professor Lavelle emphasized it is because delta G naught is always the same because it is referring to when the reactants/products are at standard temperature/pressure. As the rxn goes towards equilibrium, d...
- Tue Feb 18, 2020 4:48 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Reversible and Irreversible
- Replies: 5
- Views: 486
Re: Reversible and Irreversible
Yes, since entropy is a state function, the second law can be applied to irreversible reactions.
- Tue Feb 18, 2020 4:47 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat Capacity for Calorimeters.
- Replies: 4
- Views: 493
Re: Heat Capacity for Calorimeters.
The difference between the two is that a regular calorimeter is simply a "thermally insulated container" while in a bomb calorimeter, the reaction takes place in a sealed metal container that is immersed in water in an insulated container.
- Tue Feb 18, 2020 4:46 pm
- Forum: Van't Hoff Equation
- Topic: Units of Partial Pressure in 5G-13, 5G-15
- Replies: 3
- Views: 283
Re: Units of Partial Pressure in 5G-13, 5G-15
Calculating the Q value with partial pressures gives you an answer without units. Therefore, it isn't necessary to convert the values in bars.
- Tue Feb 11, 2020 8:57 pm
- Forum: Phase Changes & Related Calculations
- Topic: Expansion Work
- Replies: 6
- Views: 478
Expansion Work
How do we tell if a reaction does expansion work or not?
- Mon Feb 10, 2020 8:21 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Thermodynamics
- Replies: 6
- Views: 324
Re: Thermodynamics
Yup, both would be negative.
- Thu Feb 06, 2020 1:14 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: sapling problems assignment 3
- Replies: 1
- Views: 100
Re: sapling problems assignment 3
C in C∆T is heat capacity, while C in mC∆T is specific heat (Cs). C = mass x Cs, so those two equations are essentially equivalent. You use heat capacity when you don't have a total mass. That is if you know the total mass of the system, you can use the specific heat capacity. In most problems where...
- Thu Feb 06, 2020 1:09 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Thermodynamics
- Replies: 6
- Views: 324
Re: Thermodynamics
Heat transfer to a system is positive, and heat transfer from a system is negative. W is positive if work is done by the system, and negative if work is done on the system.
- Thu Feb 06, 2020 1:08 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Entropy V.S Enthalpy QUestion
- Replies: 3
- Views: 396
Re: Entropy V.S Enthalpy QUestion
I think the table on this page does a good job of answering your question, though it also depends on temperature:
https://opentextbc.ca/introductorychemi ... erature-2/
https://opentextbc.ca/introductorychemi ... erature-2/
- Thu Feb 06, 2020 1:05 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Textbook question 4D.9
- Replies: 3
- Views: 150
Re: Textbook question 4D.9
To get energy density in kJ/L from kJ/L, you divide the amount of energy with the mass of one mole of TNT and multiply it by the density of TNT. The answer should be 23.9 x 10^3 kJ/L.
3292 / 227.13 x 1650=23.9 x 10^3 kJ/L
3292 / 227.13 x 1650=23.9 x 10^3 kJ/L
- Thu Feb 06, 2020 1:01 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Textbook question 4B.3
- Replies: 3
- Views: 134
Re: Textbook question 4B.3
I got 490 J as well. I believe the answer in the book is wrong.
- Sat Feb 01, 2020 1:30 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Degeneracy
- Replies: 1
- Views: 107
Re: Degeneracy
I found this online: "Degeneracy plays a fundamental role in quantum statistical mechanics. For an N-particle system in three dimensions, a single energy level may correspond to several different wave functions or energy states. These degenerate states at the same level are all equally probable...
- Sat Feb 01, 2020 1:28 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Textbook question 4D.3
- Replies: 1
- Views: 105
Re: Textbook question 4D.3
The heat of the reaction is equal to the negative heat of the calorimeter because the calorimeter is gaining heat from the reaction. Hence to calculate heat gained by the calorimeter, we use C(delta T). The question asks for the internal energy change for the reaction of 1.00 mol CO. We are given 1....
- Sat Feb 01, 2020 1:27 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Self-Test 6A.3A
- Replies: 2
- Views: 241
Re: Self-Test 6A.3A
Basically, because hydroiodic acid is a strong acid, it dissociates completely in an aqueous solution. This means that the hydronium concentration is equivalent to the initial molarity of the acid. The back of the book represented this value in micromoles, so instead of just writing it as 6.0x10^-5,...
- Sat Feb 01, 2020 1:26 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Textbook question 4D.9
- Replies: 3
- Views: 150
Re: Textbook question 4D.9
That is correct the O2 and N2 are diatomic gases in their most stable form and thus their standard enthalpy of formation is zero. Using the enthalpies of formation we calculate that CO2 requires -393.51 kJ/mol while H20 requires -241.82. Given TNT's enthalpy of formation we calculate: 28(-393.51 kJ/...
- Sat Feb 01, 2020 1:23 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: q and delta H
- Replies: 2
- Views: 182
Re: q and delta H
q is the amount of heat transferred to a system whereas is used to describe the change in enthalpy. Enthalpy is the total potential energy of a system, which is associated with the heat transferred to/from a system (q). However, at constant pressure which can make it difficult to see the difference ...
- Sun Jan 26, 2020 4:08 pm
- Forum: Phase Changes & Related Calculations
- Topic: Enthalpy vs. Energy
- Replies: 2
- Views: 119
Re: Enthalpy vs. Energy
Enthalpy is equal to the system's internal energy plus the product of its pressure and volume. In a closed system, the heat absorbed or released equals the change in enthalpy.
- Sun Jan 26, 2020 4:06 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: using volume in calculations
- Replies: 2
- Views: 168
Re: using volume in calculations
Yup, you assume that its a cylinder.
- Sun Jan 26, 2020 4:05 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Textbook question 4C.3
- Replies: 2
- Views: 121
Re: Textbook question 4C.3
a. 343 degrees K
b. 373 degrees K
b. 373 degrees K
- Sun Jan 26, 2020 4:03 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Method 3
- Replies: 2
- Views: 179
Re: Method 3
As long as pressure is at 1 atm and the temperature is 25 degrees Celsius, the reaction is in standard state.
- Sun Jan 26, 2020 4:02 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Enthalpies
- Replies: 3
- Views: 139
Re: Enthalpies
The standard enthalpy of formation is the change in enthalpy that accompanies the formation of one mole of the compound from its elements. The standard enthalpy of reaction occurs in a system when one mole of matter is transformed by a chemical reaction.
- Sat Jan 18, 2020 5:33 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 6D. 7
- Replies: 3
- Views: 154
Re: 6D. 7
To start this problem, you would need to convert the pH into molarity by using 10^-4.60. Then, set up an ICE table with the molarity found as the H3O+ equilibrium concentration. Set the initial condition of HClO to x then subtract the molarity found from that, which will be the final equilibrium of ...
- Sat Jan 18, 2020 5:22 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Pressure
- Replies: 3
- Views: 137
Re: Pressure
A change in pressure or volume will result in an attempt to restore equilibrium by creating more or less moles of gas. For example, if the pressure in a system increases or the volume decreases, the equilibrium will shift to favor the side of the reaction that involves fewer moles of gas.
- Sat Jan 18, 2020 5:21 pm
- Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
- Topic: Buffer questions
- Replies: 4
- Views: 745
Re: Buffer questions
If buffer questions were covered in either the chemical equilibrium or acids/bases outlines, then we probably have to know them.
- Sat Jan 18, 2020 5:20 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5G.1
- Replies: 2
- Views: 109
Re: 5G.1
Yup, temperature is the one thing that would affect the K value.
- Sat Jan 18, 2020 5:19 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 6D. 13
- Replies: 2
- Views: 139
Re: 6D. 13
B) C) D) are weak so you can calculate their pH using a regular ICE box.
A) is a strong acid so its pH is simply -log(0.00005)
A) is a strong acid so its pH is simply -log(0.00005)
- Wed Jan 08, 2020 5:25 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Reaction Direction
- Replies: 5
- Views: 287
Re: Reaction Direction
Q, which is the reactant quotient, is used to identify the direction of the reaction. By comparing the Q value, which is found with the same equation as the K value, with the K value, you can identify the direction. If Q < K then the reaction proceeds forwards but if Q > K then the reverse reaction ...
- Wed Jan 08, 2020 5:21 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Clarification on Q<K and R&P concentrations
- Replies: 2
- Views: 120
Re: Clarification on Q<K and R&P concentrations
Q is mainly used to determine the favored reaction direction. It doesn't necessarily signify that the reactants or products have a higher or less concentration than one another.
- Wed Jan 08, 2020 5:18 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: How to find stability based off of equilibrium concentrations
- Replies: 2
- Views: 166
Re: How to find stability based off of equilibrium concentrations
A large equilibrium constant favors the products of dissociation, which means F2 would tend to split apart into two F and is therefore unstable. So, in comparison, Cl2 is more stable.
- Wed Jan 08, 2020 5:17 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: reactants compared to products
- Replies: 4
- Views: 167
Re: reactants compared to products
The equilibrium constant would be smaller with a higher concentration of reactants since the reactants make up the denominator of the formula.
- Wed Jan 08, 2020 5:13 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: units
- Replies: 3
- Views: 217
Re: units
By definition, the equilibrium constant has no units, as we're supposed to be using active masses instead of the molarity/ concentrations of the respective substances.
- Sun Dec 08, 2019 6:22 pm
- Forum: Octet Exceptions
- Topic: Octet exception
- Replies: 14
- Views: 1324
Re: Octet exception
Any element beyond Na would have the exception.
- Sun Dec 08, 2019 6:21 pm
- Forum: General Science Questions
- Topic: 50 post grade
- Replies: 25
- Views: 1923
Re: 50 post grade
I think it depends on your TA.
- Sun Dec 08, 2019 6:20 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR of S02
- Replies: 4
- Views: 864
Re: VSEPR of S02
Yup, bent and AX2E
- Sun Dec 08, 2019 6:19 pm
- Forum: Student Social/Study Group
- Topic: Class Grading
- Replies: 44
- Views: 3898
Re: Class Grading
I hope he ends up curving the class.
- Sat Dec 07, 2019 9:15 pm
- Forum: Lewis Structures
- Topic: ClF4+ Lewis Structure
- Replies: 2
- Views: 2785
ClF4+ Lewis Structure
Why does the lewis structure for ClF4+ place a formal charge of -1 on the central Cl atom when you could double bond one of the F atoms and move the formal charge of -1 to one of the non-central atoms?
- Wed Nov 27, 2019 4:36 pm
- Forum: Amphoteric Compounds
- Topic: Amphoteric Compounds other than Be, Al, Ga, Sn, Pb, and Sb
- Replies: 3
- Views: 273
Re: Amphoteric Compounds other than Be, Al, Ga, Sn, Pb, and Sb
The definition of amphoteric is a species that is able to act as both a base and acid, which means it should be able to accept and donate a proton when need be. The easiest way to remember is if the elements in question are part of the metalloid oxides section of the periodic table as opposed to the...
- Wed Nov 27, 2019 4:33 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Acids
- Replies: 13
- Views: 1620
Re: Acids
He will probably ask questions about acid/base strength based on the list given. As long as you know how to find strength, you would be able to answer the questions based on those 7.
- Wed Nov 27, 2019 4:30 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Inorganic vs organic
- Replies: 5
- Views: 349
Re: Inorganic vs organic
Acids and bases containing carbon are known as organic. Acids and bases that DO NOT contain carbon are known as inorganic.
- Wed Nov 27, 2019 4:29 pm
- Forum: Naming
- Topic: Simple Definitions
- Replies: 1
- Views: 178
Re: Simple Definitions
A coordination complex is the product of a Lewis acid-base reaction in which neutral molecules or anions (called ligands) bond to a central metal atom (or ion) by coordinate covalent bonds. Compounds that contain a coordination complex are called coordination compounds. Ligands are Lewis bases - the...
- Wed Nov 27, 2019 4:28 pm
- Forum: Biological Examples
- Topic: EDTA
- Replies: 8
- Views: 589
Re: EDTA
EDTA is used for chelation therapy. Chelation means "to grab" or "to bind." When EDTA is injected into the veins, it "grabs" heavy metals and minerals such as lead, mercury, copper, iron, arsenic, aluminum, and calcium and removes them from the body. It is used to treat...
- Tue Nov 19, 2019 4:22 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: SO3(2-)
- Replies: 3
- Views: 1348
SO3(2-)
Is SO3(2-) polar or nonpolar?
- Tue Nov 19, 2019 3:55 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: 3F.1 C
- Replies: 3
- Views: 188
Re: 3F.1 C
Molecular size determines intermolecular interaction strength. Since Iodine is a larger atom than Fluorine, it has stronger intermolecular strength and therefore a higher melting point.
- Tue Nov 19, 2019 3:51 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 2 related HW problems
- Replies: 2
- Views: 253
Re: Test 2 related HW problems
The questions on the syllabus from 3F, 2E, and anything that covers sigma and pi bonds, so 2F.1 will cover topics on the test.
- Tue Nov 19, 2019 3:49 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Thiosulfate Ion
- Replies: 4
- Views: 336
Re: Thiosulfate Ion
If the formal charges should be on the atom with the greatest electronegativity, then shouldn't the double bonds be to one oxygen and one sulfur? Then the other two oxygen would both have a formal charge of -1.
- Tue Nov 19, 2019 1:36 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Thiosulfate Ion
- Replies: 4
- Views: 336
Re: Thiosulfate Ion
That would create a formal charge of -1 on both the single-bonded oxygen and sulfur. If you put double bonds on all of them, it would create a formal charge of -2 on the central sulfur. Isn't that identical in terms of formal charge?
- Tue Nov 19, 2019 12:38 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Thiosulfate Ion
- Replies: 4
- Views: 336
Thiosulfate Ion
What is the lewis dot structure for a thiosulfate ion? I drew it with a Sulfur in the middle with double bonds to three oxygen and the other sulfur. This would give the central sulfur a -2 formal charge.
- Sat Nov 16, 2019 6:00 pm
- Forum: Resonance Structures
- Topic: Resonance Structures
- Replies: 1
- Views: 251
Re: Resonance Structures
CO has 10 valence electrons in total. A triple bond would be 6 electrons and a lone pair on both the C and the O would add another 4, making 10 total while also fulfilling the octet rule for both.
- Sat Nov 16, 2019 5:58 pm
- Forum: Dipole Moments
- Topic: Polarity
- Replies: 7
- Views: 490
Re: Polarity
CCl4 has a tetrahedral shape that is symmetrical. Therefore, the bond polarity is canceled out.
- Thu Nov 14, 2019 1:17 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Rotation of Polar Molecules in Dipole-Dipole Forces
- Replies: 1
- Views: 185
Rotation of Polar Molecules in Dipole-Dipole Forces
How does the rotation of various energy orientations work in dipole-dipole forces? Essentially, what does the explanation for figure 3F.5 mean?
- Thu Nov 14, 2019 1:16 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Dipole-Dipole vs. Ion-Dipole
- Replies: 2
- Views: 220
Dipole-Dipole vs. Ion-Dipole
Why does the strength of the interaction in dipole-dipole forces depend more heavily on distance than the strength of interaction in ion-dipole forces?
- Thu Nov 14, 2019 1:12 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Ion-Dipole
- Replies: 2
- Views: 123
Ion-Dipole
Does a larger extent of hydration mean a stronger intermolecular attraction?
- Sun Nov 10, 2019 10:47 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: central atom
- Replies: 21
- Views: 1069
Re: central atom
What do you do for exceptions? Such as in an atom consisting of N and O, which would be the central atom? O technically has the lower ionization energy than N. Does the number of desired bonds matter when considering the central atom more than the electronegativity? I believe the atom with the lowe...
- Sun Nov 10, 2019 10:45 pm
- Forum: Bond Lengths & Energies
- Topic: test 2
- Replies: 16
- Views: 931
Re: test 2
Also, is test 2 worth the same amount as test 1?
- Sun Nov 10, 2019 10:44 pm
- Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
- Topic: Viscosity
- Replies: 25
- Views: 3398
Re: Viscosity
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. Liquids with high viscosity have more of a resistance to deformation.
- Sun Nov 10, 2019 10:43 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: polarizability and polarizing power
- Replies: 4
- Views: 320
Re: polarizability and polarizing power
Polarizing power follows the same trend as electronegativity while polarizability follows the trend of atomic radius.
- Sun Nov 10, 2019 10:41 pm
- Forum: Ionic & Covalent Bonds
- Topic: Bond Strength
- Replies: 3
- Views: 187
Re: Bond Strength
Giving electrons is a lot stronger than sharing electrons.
- Sun Nov 03, 2019 11:28 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: rydberg equation
- Replies: 2
- Views: 154
Re: rydberg equation
What's the way Lavelle taught us how to solve it?
- Sun Nov 03, 2019 11:25 pm
- Forum: Trends in The Periodic Table
- Topic: ionization energy vs electronegativity
- Replies: 4
- Views: 196
Re: ionization energy vs electronegativity
Ionization energy: the energy required to remove an electron from a neutral atom.
Electronegativity: the ability of an atom in a molecule to draw bonding electrons to itself.
Electronegativity: the ability of an atom in a molecule to draw bonding electrons to itself.
- Sun Nov 03, 2019 9:39 pm
- Forum: DeBroglie Equation
- Topic: Ch.1 #41 [ENDORSED]
- Replies: 7
- Views: 2473
Re: Ch.1 #41 [ENDORSED]
The answer is 3956 m/s.
- Sun Nov 03, 2019 5:58 pm
- Forum: Properties of Electrons
- Topic: Question 1.15 on homework
- Replies: 16
- Views: 10494
Re: Question 1.15 on homework
How can you tell that the transition is in the Lyman series from the fact that it is in the ultraviolet spectrum of atomic hydrogen? Lyman series are the only series found in the ultraviolet spectrum of atomic hydrogen. By knowing that the transition is in the ultraviolet spectrum allows us to know...
- Sun Nov 03, 2019 5:36 pm
- Forum: Properties of Light
- Topic: HW #1.7
- Replies: 5
- Views: 1396
Re: HW #1.7
SammiOrsini_1B wrote:I think i am a little confused too. I thought there were 10^-9 meters in a nanometer and 10^-12 meters in picometer.
This should be right. Use dimensional analysis with these numbers in order to convert from meters to nanometers/picometers.
- Sun Oct 27, 2019 7:58 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: p-orbitals
- Replies: 11
- Views: 495
Re: p-orbitals
If we're writing a larger p-orbital values, can we use a noble gas to substitute? Ex. [Ne]3s^1
- Sun Oct 27, 2019 7:54 pm
- Forum: Ionic & Covalent Bonds
- Topic: Double and single bond lengths
- Replies: 6
- Views: 285
Re: Double and single bond lengths
The double bond consists of two types of bonds, the pi bond and the sigma bond. The sigma bond is stronger than the pi bond which results in a shorter bond length. As for a triple bond, there are two pi bonds and one sigma bond, which results in an even shorter bond length. What is the difference b...
- Sun Oct 27, 2019 7:52 pm
- Forum: Trends in The Periodic Table
- Topic: Ionization energy vs. electron affinity
- Replies: 1
- Views: 82
Re: Ionization energy vs. electron affinity
I don't exactly know what questions will be asked about the two but they are different. Ionization energy refers to the amount of energy necessary to remove the outermost electron of an atom or molecule. Electron affinity refers to the amount of energy necessary for a neutral ion to gain an electron...
- Sun Oct 27, 2019 7:49 pm
- Forum: Ionic & Covalent Bonds
- Topic: Homework
- Replies: 13
- Views: 689
Re: Homework
Nathan Rothschild_3D wrote:I would recommend doing it on the chemical bonds section but since part of this last week included the quantum realm, it should still be okay to do some problems from that section.
From what I've seen, this is right. It should be okay to do problems from either section.
- Sun Oct 27, 2019 7:43 pm
- Forum: Ionic & Covalent Bonds
- Topic: Covalent Bonds
- Replies: 11
- Views: 577
Re: Covalent Bonds
504939134 wrote:Covalent bonds can only be formed by nonmetals, and metals are more likely to form ionic bonds. Remember that metals often times become cations because it is easier for them to give up electrons. Non metals have high ionization energy.
Nonmetals can also form ionic bonds, right?
- Sun Oct 20, 2019 4:19 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Quantum Numbers
- Replies: 9
- Views: 413
Re: Quantum Numbers
I believe they are used in more complicated experiments and more detailed chemistry, but in terms of this class, we probably won't be going over them since those elements don't come up.
- Sun Oct 20, 2019 4:17 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: paired and parallel electrons
- Replies: 3
- Views: 177
Re: paired and parallel electrons
When two electrons are parallel, both will be having the same spin or both going up/going down. When two electrons are paired, they will have opposite spins, one going up and one going down. If two electrons are in the same orbital they will always have opposite spins (paired). If they are in two di...
- Sun Oct 20, 2019 4:16 pm
- Forum: Properties of Electrons
- Topic: Subshell Exceptions
- Replies: 6
- Views: 513
Re: Subshell Exceptions
"Exceptions are based on the fact that half-full or full shells or subshells are more stable than partially filled ones. When the difference in energy levels between two subshells is small, an electron may transfer to the higher level shell to fill or half-fill it. The electron occupies the hig...
- Sun Oct 20, 2019 2:56 pm
- Forum: Photoelectric Effect
- Topic: Sodium Vapor Lamps (1.19 hw) [ENDORSED]
- Replies: 7
- Views: 14484
Re: Sodium Vapor Lamps (1.19 hw) [ENDORSED]
Ohhhh, just got it. Thank you!
- Tue Oct 15, 2019 11:56 pm
- Forum: Photoelectric Effect
- Topic: Sodium Vapor Lamps (1.19 hw) [ENDORSED]
- Replies: 7
- Views: 14484
Re: Sodium Vapor Lamps (1.19 hw) [ENDORSED]
b) First, you convert mg to g 5.00 mg * (1g/1000mg) = 5.00 x 10^-3 g of Na Since, it's asking for the how much energy is emitted by an excited SODIUM, you use the molar mass of Na 5.00x10^-3 g Na * (1 mol Na/ 23g Na) * (6.022 x10^23 atoms Na/ 1 g Na) = 1.31 x10^20 atoms of Na (1.31 x10^20 atoms Na)...
- Sun Oct 13, 2019 9:35 pm
- Forum: Administrative Questions and Class Announcements
- Topic: How to find my posts
- Replies: 163
- Views: 177246
Re: How to find my posts
You can find your grades on the study list on myUCLA. Next to each class is a link to your grades for that class.
- Sun Oct 13, 2019 9:33 pm
- Forum: Student Social/Study Group
- Topic: Final Jitters
- Replies: 457
- Views: 432016
Re: Final Jitters
Getting a good night's sleep is important and helps me with anxiety before tests.
- Sun Oct 13, 2019 9:30 pm
- Forum: Properties of Light
- Topic: Frequency, Wavelength, Amplitude, and Velocity
- Replies: 4
- Views: 188
Re: Frequency, Wavelength, Amplitude, and Velocity
Velocity is a product of wavelength and frequency in terms of wavelength.
- Sun Oct 13, 2019 8:30 pm
- Forum: SI Units, Unit Conversions
- Topic: knowing how many sig figs to use
- Replies: 17
- Views: 824
Re: knowing how many sig figs to use
Is it usually safe to have four decimal places for calculations and answers?
- Sun Oct 13, 2019 8:26 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3931741
Re: Post All Chemistry Jokes Here
How often do I tell chemistry jokes? Periodically!
- Fri Oct 04, 2019 1:16 am
- Forum: Molarity, Solutions, Dilutions
- Topic: E 27
- Replies: 6
- Views: 1307
Re: E 27
Yup, that's what I got too.
- Thu Oct 03, 2019 11:06 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: E 29 part c
- Replies: 15
- Views: 3326
Re: E 29 part c
Because it is just the percentage of mass of oxygen, then the original mass of 8.61g copper(II) chloride tetrahydrate doesn't matter. No matter how many grams of the sample you have the percentage mass of oxygen should always be the same because of the molar ratios. Correct me if I'm wrong! Yup, th...