Search found 69 matches

by Chris Charton 1B
Sat Mar 14, 2020 9:47 pm
Forum: General Rate Laws
Topic: Initial Rate
Replies: 5
Views: 91

Re: Initial Rate

They will only change the concentration of one substance from trial to trial
by Chris Charton 1B
Sat Mar 14, 2020 9:45 pm
Forum: General Rate Laws
Topic: Factors Affecting k
Replies: 16
Views: 158

Re: Factors Affecting k

I believe we only go over temperature changing rate, however it can be changed by altering activation energy as well(adding or removing a catalyst) It is related in the Arrhenius equation; k=Ae^(-Ea/RT) I think we have to understand the concept of catalysts, but not necessarily how to compute an equ...
by Chris Charton 1B
Sat Mar 14, 2020 9:41 pm
Forum: General Rate Laws
Topic: Rate Constant
Replies: 3
Views: 74

Re: Rate Constant

Rate can be changed by altering temperature or activation energy (adding or removing a catalyst)

It is related in the Arrhenius equation; k=Ae^(-Ea/RT)
by Chris Charton 1B
Sat Mar 14, 2020 9:36 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Enthalpy
Replies: 12
Views: 260

Re: Enthalpy

Ivan Tadeja 1G wrote:
Fiona Latifi 1A wrote:Examples of state functions include density, internal energy, enthalpy, and entropy.


Could you also give examples of what would not be a state function?


Work is an example of a non-state (path) function
by Chris Charton 1B
Sat Mar 14, 2020 9:33 pm
Forum: General Rate Laws
Topic: Kr Units for Different Order Reactions
Replies: 3
Views: 83

Re: Kr Units for Different Order Reactions

Because rate is expressed in M/s, you have to adjust the units for k depending on the order. 0 order; units from [concentration (m/l)]^0 is removed, so k's units are M/s 1st order; units from [concentration (m/l)]^1 is present, so k's units are 1/s 2nd order units from [concentration(m/l)]^2 needs t...
by Chris Charton 1B
Sat Mar 14, 2020 9:21 pm
Forum: Balancing Redox Reactions
Topic: flipping equations
Replies: 7
Views: 125

Re: flipping equations

The E(cell) has to be positive, so the cathode will always be the larger (more positive) reduction potential value, and the anode will then "be flipped" so that it is giving off an electron (oxidized).
by Chris Charton 1B
Sat Mar 14, 2020 9:14 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: intensive vs extensive
Replies: 7
Views: 150

Re: intensive vs extensive

Intensive properties are not effected by the amount of the substance. For example boiling point or molecular weight.

Extensive properties are effected by the amount of the substance. For example mass or volume of a gas.
by Chris Charton 1B
Sat Mar 14, 2020 9:10 pm
Forum: Administrative Questions and Class Announcements
Topic: Grading Scale
Replies: 14
Views: 287

Re: Grading Scale

From my understanding he will only curve up if the class average is significantly lower than expected. Otherwise It's as simple as adding all your points together and dividing by 500.
by Chris Charton 1B
Sat Mar 14, 2020 9:07 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Exam Time
Replies: 13
Views: 260

Re: Final Exam Time

It opens Sunday at 11:15 AM and closes at 3 1/2 hours later at 2:45. 6 Questions.
by Chris Charton 1B
Sun Mar 08, 2020 10:13 pm
Forum: First Order Reactions
Topic: Graphing 1st order reaction rates
Replies: 6
Views: 45

Re: Graphing 1st order reaction rates

With a first order reaction graphing [A] vs t will produce a curve of exponential decay. By taking ln[A] we are able to make the graph a straight line.
by Chris Charton 1B
Sun Mar 08, 2020 10:11 pm
Forum: Zero Order Reactions
Topic: Identifying Zero vs. First vs. Second Order Reactions
Replies: 7
Views: 68

Re: Identifying Zero vs. First vs. Second Order Reactions

You can do so by looking at the graphs produced by modeling the system as 0th, 1st or 2nd order. Which ever order produces a straight line is the correct order.
by Chris Charton 1B
Sun Mar 08, 2020 10:09 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: K
Replies: 11
Views: 69

Re: K

In kinetics k is defined by the arrhenius equation, thus the temperature and activation energy.
by Chris Charton 1B
Sun Mar 08, 2020 10:07 pm
Forum: General Rate Laws
Topic: Rate limiting step
Replies: 12
Views: 94

Re: Rate limiting step

The slow step is equivalent to the rate law. If the rate law isn't given, it will specify which step is slow.
by Chris Charton 1B
Sun Mar 08, 2020 10:04 pm
Forum: General Rate Laws
Topic: units
Replies: 12
Views: 84

Re: units

The equilibrium constant does not have units
by Chris Charton 1B
Sun Mar 01, 2020 9:52 pm
Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
Topic: Dissolved Metal
Replies: 3
Views: 83

Re: Dissolved Metal

If the metal is the cathode it will come out of solution and accumulate on the electrode. If it is the anode it will "dissolve" from the electrode and go into solution.
by Chris Charton 1B
Sun Mar 01, 2020 9:45 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: when to use K or Q
Replies: 18
Views: 233

Re: when to use K or Q

K indicates the equation is at equilibrium. Q indicates that the equation is not at equilibrium.
by Chris Charton 1B
Sun Mar 01, 2020 9:44 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Electrochemical Series
Replies: 5
Views: 46

Re: Electrochemical Series

The electrochemical series are the tables of electrode potential.
by Chris Charton 1B
Sun Mar 01, 2020 8:24 pm
Forum: Balancing Redox Reactions
Topic: oxidizing agents
Replies: 11
Views: 115

Re: oxidizing agents

Oxidizing agents cause Oxidation to a substance and get reduced in the process.
by Chris Charton 1B
Sun Feb 23, 2020 8:25 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: cell diagram
Replies: 2
Views: 30

Re: cell diagram

You have the oxidation reaction (anode) on the left side of the salt bridge and the reduction reaction (cathode) on the right side | indicates substances that are touching each other but in different phases || indicates the salt bridge You also need to include the inert conductor so; Cu(s) | Cu2+(aq...
by Chris Charton 1B
Sun Feb 23, 2020 8:18 pm
Forum: Van't Hoff Equation
Topic: Van't Hoff Equation
Replies: 7
Views: 104

Re: Van't Hoff Equation

You use it when you have a given equilibrium constant K at one temperature, and then you need to find the new equilibrium constant K at a new temperature.
by Chris Charton 1B
Sun Feb 23, 2020 7:53 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: 3rd law of thermodynamics
Replies: 3
Views: 100

Re: 3rd law of thermodynamics

Yes, at 0K atoms cease to move, have zero entropy and are in a solid state. 0K is theoretical, it is not actually possible to reach.
by Chris Charton 1B
Sun Feb 23, 2020 7:50 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Enthalpy
Replies: 12
Views: 260

Re: Enthalpy

State functions only depend on initial and final values, thus intermediate steps are irrelevant when calculating enthalpy or entropy.
by Chris Charton 1B
Sun Feb 23, 2020 7:43 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Question 1 on Midterm
Replies: 7
Views: 183

Re: Question 1 on Midterm

Via Le Chatelier removing reactants from equilibrium causes the reaction to shift towards reactants, and removing products causes the reaction to shift towards products.
by Chris Charton 1B
Sun Feb 09, 2020 9:09 pm
Forum: Phase Changes & Related Calculations
Topic: closed vs isolated
Replies: 10
Views: 110

Re: closed vs isolated

A closed system can transfer energy with the surroundings while an isolated system cannot. Neither exchanges matter with the surroundings
by Chris Charton 1B
Sun Feb 09, 2020 8:59 pm
Forum: Phase Changes & Related Calculations
Topic: Phase Change Calculations
Replies: 5
Views: 50

Re: Phase Change Calculations

You can see what is included on the equation sheet here; https://lavelle.chem.ucla.edu/wp-conten ... ations.pdf
by Chris Charton 1B
Sun Feb 09, 2020 8:52 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: solids and liquids in the rxn quotient
Replies: 8
Views: 109

Re: solids and liquids in the rxn quotient

Solids and Liquids have an activity level of 1, so even if you include them in the calculations they will have no effect on the results.
by Chris Charton 1B
Sun Feb 09, 2020 8:49 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Strong acids and bases as gases
Replies: 4
Views: 60

Re: Strong acids and bases as gases

I believe we only need to know about how acids and bases behave in aqueous form.
by Chris Charton 1B
Sun Feb 09, 2020 8:48 pm
Forum: Ideal Gases
Topic: Change in pressure
Replies: 7
Views: 133

Re: Change in pressure

Because the system want to remain at equilibrium, increasing pressure will cause the equation to shift towards the side with fewer moles of gas.
by Chris Charton 1B
Mon Feb 03, 2020 6:24 pm
Forum: Phase Changes & Related Calculations
Topic: Steam?
Replies: 8
Views: 93

Re: Steam?

In order to break the hydrogen bonds found in liquid water, quite a bit of additional energy is required to be added to change water's phase from liquid to gas. This energy stays with the vaporized water molecules and it is released when it condenses back to liquid.
by Chris Charton 1B
Mon Feb 03, 2020 6:19 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Car Engine
Replies: 4
Views: 54

Re: Car Engine

It exchanges both heat and matter with the surroundings. It takes in gasoline and air and gives off exhaust. Heat is also exchanged with the air entering and exiting the engine, as well as radiation from the hot engine block.
by Chris Charton 1B
Mon Feb 03, 2020 6:15 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Specific heat capacity
Replies: 7
Views: 75

Re: Specific heat capacity

Specific heat capacity is per gram of substance. It can be converted to molar heat capacity by dividing it by the substances molar weight.
by Chris Charton 1B
Mon Feb 03, 2020 6:13 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Closed Systems
Replies: 14
Views: 215

Re: Closed Systems

An example of changing energy of a closed system would be adding or removing heat, or compression/expansion. An isolated system cannot transfer energy with its environment.
by Chris Charton 1B
Mon Feb 03, 2020 6:10 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Isolated system
Replies: 10
Views: 154

Re: Isolated system

It's my understanding that a perfectly isolated system is theoretical and impossible to create. A thermos is an example of a practically isolated system- it exchanges energy at a slow enough rate to be considered isolated for a question.
by Chris Charton 1B
Sun Jan 26, 2020 8:47 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Method 3
Replies: 3
Views: 43

Re: Method 3

Method 3 is more accurate than Method 2, you can use it as long as you know the standard enthalpy of formation of all the products and reactants. Something like O2 in gaseous form will not have a listed standard enthalpy of formation because by definition the standard enthalpy of formation for an el...
by Chris Charton 1B
Sun Jan 26, 2020 8:40 pm
Forum: Phase Changes & Related Calculations
Topic: Enthalpy is said to be additive
Replies: 10
Views: 105

Re: Enthalpy is said to be additive

This is because Enthalpy is a state property. Only the initial and final values are relevant, the path taken to get to the final value does not matter.
by Chris Charton 1B
Sun Jan 26, 2020 8:36 pm
Forum: Phase Changes & Related Calculations
Topic: phase changes
Replies: 2
Views: 44

Re: phase changes

When calculating total enthalpy you have to account for whether or not the substance is its standard phase. For example if its a gas in its standard state and is currently a liquid, you would have to add the enthalpy of its vaporization to total enthalpy.
by Chris Charton 1B
Sun Jan 26, 2020 8:32 pm
Forum: Phase Changes & Related Calculations
Topic: Phase Changes
Replies: 7
Views: 89

Re: Phase Changes

When the substance is not in its standard state at the given temperature, you have to add the enthalpy of its phase changes. For example if its a gas in its standard state and is currently a solid, you would have to add the enthalpy of its sublimation.
by Chris Charton 1B
Sun Jan 26, 2020 8:24 pm
Forum: Ideal Gases
Topic: R Constant
Replies: 18
Views: 249

Re: R Constant

R is the gas constant. It has different values depending on what units you are using.
by Chris Charton 1B
Sun Jan 19, 2020 8:53 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Not including solids and liquids
Replies: 7
Views: 74

Re: Not including solids and liquids

Pure liquids and solids have an activity level of 1, and thus do not need to be included in equilibrium equations.
by Chris Charton 1B
Sun Jan 19, 2020 7:56 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Stoichiometric coefficients for pH/pOH
Replies: 3
Views: 34

Re: Stoichiometric coefficients for pH/pOH

Raising concentrations to their stoichiometric coefficient is only required for the equilibrium equations.
by Chris Charton 1B
Sun Jan 19, 2020 7:51 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: When do we use the equilibrium sign?
Replies: 7
Views: 62

Re: When do we use the equilibrium sign?

Although only one arrow is required by strong acids/bases, I don't believe it's incorrect to use the equilibrium sign.
by Chris Charton 1B
Sun Jan 19, 2020 7:45 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5%
Replies: 4
Views: 39

Re: 5%

If you approximate the result with a small Ka (<10^-3) and end up with a change value of <5% of initial value then your approximation is valid. Otherwise you need to do the full quadratic calculation.
by Chris Charton 1B
Sun Jan 19, 2020 7:38 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Solids and Liquids
Replies: 6
Views: 56

Re: Solids and Liquids

Pure solids and liquids do not affect reactant amounts in the equation so they are not included in the equation. If you included them they would have an activity level of 1, thus not changing the equation.
by Chris Charton 1B
Sun Jan 12, 2020 7:33 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: increasing yield of NH3
Replies: 3
Views: 51

Re: increasing yield of NH3

By removing NH3 from the system, the numerator of the Qp equation will decrease, resulting in a smaller Qp value. When Qp is less than Kp the reaction moves forward, resulting in more NH3 being created. Yes it would decrease NH3 in the system, but overall you would have more NH3 (by adding NH3 in th...
by Chris Charton 1B
Sun Jan 12, 2020 7:27 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: increasing N2
Replies: 5
Views: 79

Re: increasing N2

Increasing N2 will result in a larger denominator for the Qp equation, resulting in a smaller value for Qp. When Qp is less than Kp, the reaction moves forward, meaning that more NH3 will be created from N2 and H2, resulting in H2 concentration decreasing.
by Chris Charton 1B
Sun Jan 12, 2020 7:23 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Inert gas
Replies: 6
Views: 58

Re: Inert gas

Reactant and Product concentrations will remain the same as volume does not change, therefore Kp is unchanged.
by Chris Charton 1B
Sun Jan 12, 2020 7:18 pm
Forum: Administrative Questions and Class Announcements
Topic: General HW question
Replies: 9
Views: 93

Re: General HW question

I believe it depends on the TA
by Chris Charton 1B
Thu Jan 09, 2020 6:53 pm
Forum: Administrative Questions and Class Announcements
Topic: Homework 1
Replies: 18
Views: 249

Re: Homework 1

I believe it is graded on completeness, also you can check your answers with the solutions manual.
by Chris Charton 1B
Wed Jul 31, 2019 12:37 am
Forum: Naming
Topic: CO3(2-) Carbanato
Replies: 2
Views: 266

Re: CO3(2-) Carbanato

Hmm, I saw it stated as such when looking it up earlier. I see in our textbook it's only referred to as monodentate so I'm just going to go with that.
by Chris Charton 1B
Wed Jul 31, 2019 12:08 am
Forum: Naming
Topic: CO3(2-) Carbanato
Replies: 2
Views: 266

CO3(2-) Carbanato

Because CO3(2-) can either be monodentate or bidentate do we use bi- tri- etc as the prefix or bis- tris-?
by Chris Charton 1B
Tue Jul 30, 2019 11:58 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Angles
Replies: 2
Views: 207

Re: Angles

In the seesaw shape, the lone pair does not effect the axial angles. So the angles are 90, <120, and 180.
by Chris Charton 1B
Tue Jul 30, 2019 11:37 pm
Forum: Conjugate Acids & Bases
Topic: Delocalization of charge and stability
Replies: 4
Views: 570

Re: Delocalization of charge and stability

One thing it can refer to is the electronegativity of the central atom of the conjugate base. For example; ClO4- vs H2PO4- Cl is more electronegative than P, so it handles the negative charge more effectively. HClO4 is thus a stronger acid than H3PO4.
by Chris Charton 1B
Tue Jul 30, 2019 11:19 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: how to draw lewis structure
Replies: 9
Views: 430

Re: how to draw lewis structure

With a radical you assign the lone electron to the atom with the lowest Electronegativity. For example in HOCO (17 e) the lone electron would be put on C.

I checked out ClO2, it involves something called a triple electron bond, which is beyond this class.
by Chris Charton 1B
Tue Jul 30, 2019 11:09 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar v. Nonpolar
Replies: 11
Views: 1460

Re: Polar v. Nonpolar

Yes, the vectors would cancel out with that shape, but more importantly C-H is not a polar covalent bond, they both have similar Electronegativities. CH3+ would also be a symmetrical shape with canceling vectors, but again, the bonds are not polar.
by Chris Charton 1B
Tue Jul 30, 2019 10:57 pm
Forum: Conjugate Acids & Bases
Topic: Water as an Acid/Base
Replies: 20
Views: 639

Re: Water as an Acid/Base

You can recognize it because it will have a H+ to give, and be able to receive an H+.

An example would be HPO4 (2-)
by Chris Charton 1B
Tue Jul 30, 2019 10:54 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Strength of Acids vs. Number of Oxygens
Replies: 6
Views: 875

Re: Strength of Acids vs. Number of Oxygens

Yes, if the acid is polyprotic, it will be strongest when it has the most H. For example, H3PO4 is a stronger acid than H2PO4-

This is because it is easier to remove the first H.
by Chris Charton 1B
Tue Jul 30, 2019 10:47 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: shape
Replies: 2
Views: 304

Re: shape

Chem_Mod wrote:Because there are 6 ligands, 3 from the Na and 3 from the oxalate, it will have an octahedral shape.


I thought oxalate was bidentate, and thus 3 of them would provide the 6 areas.
by Chris Charton 1B
Mon Jul 29, 2019 11:31 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: What are polydentate ligands ?
Replies: 4
Views: 404

Re: What are polydentate ligands ?

Hexadentate is 6 binding sites.
by Chris Charton 1B
Mon Jul 29, 2019 11:28 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic vs covalent
Replies: 8
Views: 498

Re: Ionic vs covalent

If the difference is between 1.5 and 2 does the bond exhibit qualities of both ionic and covalent bonds?
by Chris Charton 1B
Mon Jul 29, 2019 12:38 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Oxidation states
Replies: 5
Views: 363

Re: Oxidation states

I think they might be referring to finding the oxidation state of a metal in a coordination compound.
by Chris Charton 1B
Mon Jul 29, 2019 12:30 am
Forum: Formal Charge and Oxidation Numbers
Topic: charges and roman numerals
Replies: 5
Views: 592

Re: charges and roman numerals

The Roman Numeral indicates the Oxidation State.
by Chris Charton 1B
Mon Jul 29, 2019 12:25 am
Forum: Coordinate Covalent Bonds
Topic: Why can h20 only donate 1 lone pair?
Replies: 5
Views: 787

Re: Why can h20 only donate 1 lone pair?

In my understanding with coordinate covalent bonding the element can only donate one pair to another element, no matter how many lone pairs it may have.
by Chris Charton 1B
Fri Jul 05, 2019 2:56 pm
Forum: Photoelectric Effect
Topic: kinetic energy of electron
Replies: 8
Views: 601

Re: kinetic energy of electron

How can something be released with a KE of 0? That would mean it has no velocity, so its position would not change.
by Chris Charton 1B
Thu Jun 27, 2019 10:12 am
Forum: SI Units, Unit Conversions
Topic: Use of Kelvin
Replies: 6
Views: 483

Re: Use of Kelvin

Temperature is the measure of the average kinetic energy of the particles of a substance. At absolute zero the kinetic energy of the particles is zero, ie they stop moving. Because you can't have negative kinetic energy, you can't go past zero.
by Chris Charton 1B
Thu Jun 27, 2019 10:06 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Moles and Molarity HW Problem E.29b
Replies: 2
Views: 265

Re: Moles and Molarity HW Problem E.29b

In each molecule of CuCl2 there will be two ions of Cl, hence you need to double the amount of moles found of CuCl2 to find the number of moles of Cl- ions.
by Chris Charton 1B
Thu Jun 27, 2019 9:59 am
Forum: Molarity, Solutions, Dilutions
Topic: the mole
Replies: 4
Views: 347

Re: the mole

Grams per cubic centimeter is also commonly used.

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