Search found 143 matches
- Sun Mar 14, 2021 1:09 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Effect of Temp. on K constant
- Replies: 8
- Views: 494
Re: Effect of Temp. on K constant
For an exothermic reaction, if temperature increased, the K would decrease
- Sun Mar 14, 2021 1:08 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Value of N
- Replies: 24
- Views: 1083
Re: Value of N
N is the number of electrons being transferred. This can be found by determining the oxidation numbers of the species being reduced and oxidized
- Sun Mar 14, 2021 1:07 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Salt Bridges
- Replies: 12
- Views: 805
Re: Salt Bridges
A salt bridge helps prevent a build up of charge. As electrons flow from the anode to the cathode, the cathode begins to decrease in charge, making its ability to pull electrons weaker. In order to stop this, the salt bride sends an anion from the cathode solution to the anode in order to maintain t...
- Sun Mar 14, 2021 1:04 am
- Forum: General Rate Laws
- Topic: Intermediate
- Replies: 59
- Views: 3519
Re: Intermediate
An intermediate is a species that is not a reactant nor product in the overall balanced equation but is formed and then consumed in the elementary steps of the reaction.
- Sun Mar 14, 2021 1:03 am
- Forum: General Rate Laws
- Topic: Pseudo Rates
- Replies: 8
- Views: 678
Re: Pseudo Rates
They are used when we have multiple reactants and want to determine the order of each one. In doing so, we focus on one reactant at a time and make the concentration of all the other reactants very high so that they essentially do not change and, thus, we can ignore them
- Sun Mar 14, 2021 1:03 am
- Forum: General Rate Laws
- Topic: Pseudo Rates
- Replies: 8
- Views: 678
Re: Pseudo Rates
They are used when we have multiple reactants and want to determine the order of each one. In doing so, we focus on one reactant at a time and make the concentration of all the other reactants very high so that they essentially do not change and, thus, we can ignore them
- Sun Mar 14, 2021 1:01 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: K = kforward/kreverse
- Replies: 16
- Views: 1032
Re: K = kforward/kreverse
Yes! The ratio of the forward k and reverse k equals the equilibrium constant
- Sun Mar 14, 2021 1:00 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Catalyst
- Replies: 27
- Views: 1049
Re: Catalyst
It is changing the pathway for both the forward and reverse reaction by lowing the activation energy, increasing the speed of both
- Mon Mar 08, 2021 10:51 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: n in ∆G = -nFE
- Replies: 80
- Views: 3816
Re: n in ∆G = -nFE
n refers to the number of mols of electrons being transferred and to do find this look at the difference in oxidation numbers of the species being reduced and oxidized
- Mon Mar 08, 2021 10:50 am
- Forum: Ideal Gases
- Topic: Conditions
- Replies: 20
- Views: 1476
Re: Conditions
Pressure is 1 atm and and temperature is 273 K
- Mon Mar 08, 2021 10:49 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Q and K
- Replies: 40
- Views: 2635
Re: Q and K
If Q is larger than K, then the reaction will go in the reverse direction. If K is greater than Q then the reaction will move in the forward direction. And when Q equals K, then that means the reaction has reached equilibrium
- Mon Mar 08, 2021 10:48 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K
- Replies: 33
- Views: 1249
Re: K
Kc is the K value but when using concentrations to determine it. Both are equilibrium constants
- Mon Mar 08, 2021 10:47 am
- Forum: Calculating Work of Expansion
- Topic: Negative Work
- Replies: 30
- Views: 1174
Re: Negative Work
When the system is expanding/doing work, it is pushing eternal air out of the way in order to expand, therefore doing work. And when the system does work it is losing energy, making the work term a negative value
- Mon Mar 08, 2021 10:46 am
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: About k
- Replies: 26
- Views: 2744
Re: About k
If k is large that means that the forward reaction is favored because the products a more stable/favored.
- Mon Mar 08, 2021 10:45 am
- Forum: Calculating Work of Expansion
- Topic: Work and Delta V
- Replies: 20
- Views: 2427
Re: Work and Delta V
Yes in this class we are only focusing on work by expansion/reduction and if the volume is constant then we say that there is no work being donee.
- Mon Mar 08, 2021 10:45 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: mmol
- Replies: 6
- Views: 372
Re: mmol
There are 1000 mmol in every mol. Therefore to convert mmol to mol simple divide your mmol value by 1000.
- Sun Feb 28, 2021 11:47 pm
- Forum: Phase Changes & Related Calculations
- Topic: Endothermic v. Exothermic
- Replies: 139
- Views: 10309
Re: Endothermic v. Exothermic
Yes an endothermic reaction always has a positive delta H value and exothermic reaction always has a negative delta H value.
- Sun Feb 28, 2021 11:46 pm
- Forum: Phase Changes & Related Calculations
- Topic: State Property
- Replies: 71
- Views: 2910
Re: State Property
It means that you only need to know the final and initial conditions in order to measure this property.
- Sun Feb 28, 2021 11:44 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Spontaneous vs Nonspontaneous
- Replies: 4
- Views: 249
Re: Spontaneous vs Nonspontaneous
The reaction is spontaneous if delta G naught is a negative value and/or E naught is positive
- Sun Feb 28, 2021 11:43 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Anodes and Cathodes
- Replies: 22
- Views: 963
Re: Anodes and Cathodes
Cathode has the higher potential and, therefore, electrons typically flow into the cathodes
- Sat Feb 27, 2021 5:25 pm
- Forum: Balancing Redox Reactions
- Topic: Sapling #5
- Replies: 1
- Views: 135
Sapling #5
For question 5 on weeks 7 and 8 sapling assignment it asks you to balance the equation Cl2O7(g)+H2O2(aq)⟶ClO−2(aq)+O2(g). I identified that the Cl2O7 was the oxidizing agent and the H202 was the reducing agent but could someone please walk me through their thought process on how to balance this equa...
- Wed Feb 24, 2021 9:40 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: Electron Transfer
- Replies: 1
- Views: 138
Electron Transfer
Why is electron transfer in water faster in the presence of ions?
- Tue Feb 23, 2021 11:19 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: W(max) = delta G
- Replies: 3
- Views: 235
W(max) = delta G
Why is it that at constant temperature and pressure, W (max) = delta G
- Mon Feb 22, 2021 7:40 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Electrodes
- Replies: 4
- Views: 256
Electrodes
What exactly is an electrode? and why do you always need a solid/metal electrode
- Mon Feb 22, 2021 6:19 pm
- Forum: Balancing Redox Reactions
- Topic: Balancing redox reactions and standard reduction potential
- Replies: 7
- Views: 463
Balancing redox reactions and standard reduction potential
So in lecture Dr. Lavelle mentions that standard reduction potential is an intensive property so it stays the same. But I was wondering if when we multiply the reaction to balance it, do we also multiple the E value by the same number we multiplied the equation by (similar to how when we multiplied ...
- Sun Feb 21, 2021 7:05 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Irreversible vs. Reversible Work Functions
- Replies: 6
- Views: 450
Re: Irreversible vs. Reversible Work Functions
Reversible work functions occur when the external pressure and internal pressure are very close in value and the system is essentially in equilibrium. For an irreversible reaction the external pressure is much less than the internal pressure so the process expands quickly.
- Sun Feb 21, 2021 7:04 pm
- Forum: Calculating Work of Expansion
- Topic: Negative Work
- Replies: 30
- Views: 1174
Re: Negative Work
This is because when a system is expanding/voluume is increase, it is doing work of expansion so its losing energy, explaining why the sign for work would be negative
- Sun Feb 21, 2021 7:02 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: 4J.5 Standard change in gibbs free energy
- Replies: 6
- Views: 350
Re: 4J.5 Standard change in gibbs free energy
It just wants to make sure you understand the different ways of calculating free energy
- Sun Feb 21, 2021 7:01 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: C vs Cs/Cm
- Replies: 8
- Views: 1589
Re: C vs Cs/Cm
Molar heat capacity is the energy required to increase 1 mol of a substance by 1 degree (so its heat capacity divided by mols) and specific heat capacity is the energy required to increase 1 gram of a substance by 1 degree (so its heat capacity divided by grams
- Sun Feb 21, 2021 6:59 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Open vs closed
- Replies: 31
- Views: 2774
Re: Open vs closed
Open system means it can exchange matter and energy with its surroundings. Closed system means only energy can be exchanged with surroundings. And an isolated system means that neither matter nor energy can be exchanged.
- Sun Feb 21, 2021 6:56 pm
- Forum: Calculating Work of Expansion
- Topic: adiabatic processes
- Replies: 18
- Views: 833
Re: adiabatic processes
adiabatic process are when no heat is exchanged so q = 0
- Sun Feb 21, 2021 6:56 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Forward vs. Reverse
- Replies: 22
- Views: 2011
Re: Forward vs. Reverse
Forward reactions are when the reaction goes from reactants to products and reverse reaction is when the process goes from products to reactants
- Thu Feb 18, 2021 2:25 am
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: 2nd Law
- Replies: 11
- Views: 632
2nd Law
Could someone please explain to me in simple terms what the 2nd law of thermodynamics is exactly?
- Sun Feb 14, 2021 1:49 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Sign of work
- Replies: 17
- Views: 746
Re: Sign of work
If the volume decreases (work being done on system) then the sign is positive. If the volume increases (system does work) then the sign is negative.
- Sun Feb 14, 2021 1:47 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Which R to use
- Replies: 42
- Views: 2862
Re: Which R to use
You use 8.314
- Sun Feb 14, 2021 9:33 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: delta U and delta H
- Replies: 8
- Views: 348
Re: delta U and delta H
Delat U and Delta H are not the same thing. Delta U represents the change in internal energy of the system whereas delta h represents the change in enthalpy. The two are, however, equal to one another when the volume is not changing (aka when no work is being done by/to the system).
- Sun Feb 14, 2021 9:31 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Cv and Cp
- Replies: 16
- Views: 1399
Re: Cv and Cp
We need to specify this because, unlike for solids and liquids, for gases, increasing the temperature will have an effect on either the volume or pressure of the system. Moreover, for gases Cp tends to be slightly larger in value than Cv as, in order to maintain a constant pressure, the volume would...
- Sun Feb 14, 2021 9:28 am
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: week 5 and 6 sampling hw #7
- Replies: 5
- Views: 323
Re: week 5 and 6 sampling hw #7
You are supposed to calculate the change in mass by subtracting the final mass by the initial mass. And then you convert this value to mols and divide it by the energy.
- Sun Feb 14, 2021 9:24 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Work on a system
- Replies: 27
- Views: 1032
Re: Work on a system
If you/the surroundings were to apply work on the system, then work will be a positive value. For instance, if one were to push down/compress the system, he or she would be applying work on the system.
- Sun Feb 14, 2021 9:23 am
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Temperature Question
- Replies: 8
- Views: 433
Re: Temperature Question
Although they are two different temperature scales, a change of 80 degrees celsius is the same as a change of 80 degrees K. This is apparent in this example as 100 °C - 20 °C and 373 K - 293 K both give you a change in temperature value of 80.
- Wed Feb 10, 2021 1:12 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Today's lecture
- Replies: 5
- Views: 250
Today's lecture
In today's lecture Dr. Lavelle said that when delta S (universe) is positive, then the process is favorable. Do we think of delta S (universe) and delta S (total) as the same thing? In other words, if we take the sum of the delta S (system) and delta S (surrounding) to get delta S (total) and it is ...
- Wed Feb 10, 2021 1:10 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: U at Equilibrium
- Replies: 4
- Views: 294
U at Equilibrium
I understand that when equilibrium is reached, delta u equals 0. But why at equilibrium is U a minimum.
- Sun Feb 07, 2021 4:50 pm
- Forum: Phase Changes & Related Calculations
- Topic: Endo vs. exo & bond strenghts
- Replies: 8
- Views: 359
Re: Endo vs. exo & bond strenghts
Typically for an endothermic reaction, the bonds of the reactants are stronger and for an exothermic reaction, the bonds of the products are stronger.
- Sun Feb 07, 2021 4:48 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Internal Energy Definition
- Replies: 6
- Views: 223
Re: Internal Energy Definition
Internal energy is the energy of the system where as external energy is the energy of the surroundings (outside the system we are observing).
- Sun Feb 07, 2021 4:47 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Systems
- Replies: 24
- Views: 800
Re: Systems
The universe is considered an isolated system because the energy of the universe is constant. All activity we see in the universe is really one form of energy going to another.
- Sun Feb 07, 2021 4:45 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Sapling #20 Linear vs. nonlinear molecules
- Replies: 13
- Views: 533
Re: Sapling #20 Linear vs. nonlinear molecules
Yes I believe it is the same(:
- Sun Feb 07, 2021 4:44 pm
- Forum: Phase Changes & Related Calculations
- Topic: Water's Heating Curve
- Replies: 9
- Views: 503
Re: Water's Heating Curve
On the places that the curve is flat, there is a phase change occurring because at this point heat is still entering the system yet the temperature is not changing. At places where the curve is not flat, heat and temperature are changing
- Sun Feb 07, 2021 4:42 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: All the Cs
- Replies: 4
- Views: 214
Re: All the Cs
Cm is the molar heat capacity, which would be in units of J/(K*mol) and C alone is heat capacity, which does not depend on the amount of substance present
- Sun Feb 07, 2021 3:33 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Sapling Question 18
- Replies: 1
- Views: 254
Sapling Question 18
A 0.513 mol sample of Xe(g), initially at 298 K and 1.00 atm, is held at constant pressure while enough heat is applied to raise the temperature of the gas by 16.7 K.Calculate the amount of heat q required to bring about this temperature change, and find the corresponding total change in the interna...
- Sat Feb 06, 2021 8:24 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Friday's Lecture
- Replies: 8
- Views: 298
Friday's Lecture
In the last lecture, Dr. Lavelle said that q = -w, is this always true? Or only under certain conditions?
- Sun Jan 31, 2021 3:01 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Kelvin or Celsius?
- Replies: 86
- Views: 5174
Re: Kelvin or Celsius?
It is supposed to be in kelvin(:
- Sun Jan 31, 2021 2:58 pm
- Forum: Phase Changes & Related Calculations
- Topic: endothermic/exothermic
- Replies: 43
- Views: 4337
Re: endothermic/exothermic
If heat is required for the phase change to occur (like in the case of going from solid to liquid or liquid to gas) then it is endothermic and the reverse reaction would be exothermic. Another way to think about this is that if the thermal motion is increasing as a result of the phase change, then y...
- Sun Jan 31, 2021 2:55 pm
- Forum: Phase Changes & Related Calculations
- Topic: Endothermic v. Exothermic
- Replies: 139
- Views: 10309
Re: Endothermic v. Exothermic
Yes endothermic reactions will always have a positive enthalpy and exothermic reactions will always have a negative enthalpy/delta H
- Sun Jan 31, 2021 2:54 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: is HClO3 weak or strong? [ENDORSED]
- Replies: 49
- Views: 3974
Re: is HClO3 weak or strong? [ENDORSED]
I believe we are supposed to consider this a strong acid
- Sun Jan 31, 2021 2:53 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Neutralization
- Replies: 25
- Views: 984
Re: Neutralization
Neutralization is when an acid and base are combined in reaction and create water and a salt. In this case, HCl and NaOH will result in H2O and the salt NaCl
- Tue Jan 26, 2021 6:40 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Temperature Change
- Replies: 16
- Views: 739
Temperature Change
Why when you increase temperature, the k value increases for an endothermic reaction?
- Sun Jan 24, 2021 11:34 pm
- Forum: Phase Changes & Related Calculations
- Topic: when to assume x is insignificant
- Replies: 86
- Views: 6393
Re: when to assume x is insignificant
When the k value is less than 10^-4 we can assume the x value is insignificant. Also if the percent ionization is less than 5%, we know the x value is insignificant.
- Sun Jan 24, 2021 11:32 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Temperature Given in Problems
- Replies: 6
- Views: 176
Re: Temperature Given in Problems
I believed that knowing the actual temperature isn't necessarily important for the calculations we have been doing but it is important to know if temperature has changed or not because if temperature changes, then the kb/ka value will change as well.
- Sun Jan 24, 2021 11:30 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Sapling 9
- Replies: 10
- Views: 335
Re: Sapling 9
This is because if the ph is lower than the pKa value it means that the surrounding solution is more acidic than the actual species, therefore it the species will not deprotonate and will remain neutral
- Sun Jan 24, 2021 11:28 pm
- Forum: Phase Changes & Related Calculations
- Topic: weak/strong bases and acids
- Replies: 7
- Views: 418
Re: weak/strong bases and acids
In the case of acids, a low pKa or a high Ka is an indicator of a strong acid. Whereas for a base, a low pKb and/or a high Kb is an indicator of a strong base
- Sun Jan 24, 2021 11:27 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Ice Tables
- Replies: 28
- Views: 958
Re: Ice Tables
It depends on which way the reaction is moving. If it is going in the forward direction, then it would be -x for the reactants and +x for the products. If the reaction is moving in the reverse direction, then it would be -x for the products and +x for the reactants.
- Sun Jan 24, 2021 11:25 pm
- Forum: Phase Changes & Related Calculations
- Topic: Define Phase Change
- Replies: 78
- Views: 4911
Re: Define Phase Change
Phase change means that a substance has changed from one state of matter to another. An example of this would be liquid water becoming water vapor.
- Fri Jan 22, 2021 4:09 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Enthalpy units
- Replies: 7
- Views: 404
Enthalpy units
Are the units of ΔH⊖rxn always just Kj whereas the units of ΔH⊖f always Kj/mol?
- Sun Jan 17, 2021 3:10 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE Chart with Gas Pressures
- Replies: 8
- Views: 280
Re: ICE Chart with Gas Pressures
Yes we use them in the ice chart like we would with concentrations. You do not need to convert the units.
- Sun Jan 17, 2021 3:09 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: increasing/decreasing a solid/liquid
- Replies: 6
- Views: 272
Re: increasing/decreasing a solid/liquid
We do not include liquids nor solids in the equilibrium expression so the amount to solid or liquid won't cause a change in the equilibrium
- Sun Jan 17, 2021 3:07 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: shifts left or right
- Replies: 23
- Views: 1028
Re: shifts left or right
If the equation is shifting to the left, it means it will produce more reactants. If the equation is shifting to the right, it means it will produce more products
- Sun Jan 17, 2021 3:05 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Sapling HW Q10
- Replies: 2
- Views: 130
Re: Sapling HW Q10
Because the overall pH of the solution (9.57) is greater than the pKa, the neutral, deprotonated species of B will become more predominant in solution.
- Sun Jan 17, 2021 3:01 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Using the ICE table
- Replies: 36
- Views: 1314
Re: Using the ICE table
Yes you can use Ice table for both partial pressures and concentrations.
- Sun Jan 17, 2021 2:55 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: q vs k
- Replies: 62
- Views: 2375
Re: q vs k
Yes Q will eventually reach K. And Q is expressed when equilibrium has not yet been reached.
- Sun Jan 10, 2021 1:27 pm
- Forum: Ideal Gases
- Topic: Inert Gas
- Replies: 20
- Views: 565
Re: Inert Gas
Inert gases are just noble gases
- Sun Jan 10, 2021 1:26 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Calculating Equilibrium Concentrations
- Replies: 10
- Views: 386
Re: Calculating Equilibrium Concentrations
You do not include solids nor solvents because their concentrations do not change by any significant amount.
- Sun Jan 10, 2021 1:25 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: I in ICE Chart
- Replies: 11
- Views: 420
Re: I in ICE Chart
Yes if the reverse reaction were being executed then you would have an initial concentration for the products.
- Sun Jan 10, 2021 1:24 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Units
- Replies: 27
- Views: 868
Re: Units
Because 1 bar is approximately equal to 1 atm we use both and don't necessarily prefer one over the other. However, I do believe the SI unit is bar
- Sun Jan 10, 2021 1:23 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Endothermic and Exothermic Reactions
- Replies: 6
- Views: 335
Re: Endothermic and Exothermic Reactions
If you have an endothermic reaction, then you can think of heat as a reactant so if you were to release heat, the reaction would shift to the left whereas if you increase heat, it would favor the products/forward reaction.
- Sun Jan 10, 2021 1:21 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: When to use ice table
- Replies: 4
- Views: 225
Re: When to use ice table
You typically use ice chart when you know the reactants aren't being used up to completion. Usually you are given the initial conditions and you are trying to find the change in concentrations in order to determine the final equilibrium concentrations.
- Fri Dec 11, 2020 6:09 pm
- Forum: Lewis Acids & Bases
- Topic: Aluminum Chloride naming in today's review
- Replies: 4
- Views: 228
Re: Aluminum Chloride naming in today's review
Because this bond is ionic, you do not use prefixes in naming it
- Fri Dec 11, 2020 6:07 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Chelating Ligands vs Polydentate ligands
- Replies: 5
- Views: 448
Re: Chelating Ligands vs Polydentate ligands
Polydentate ligands will form chelate/ring attached to the transition metal.
- Fri Dec 11, 2020 5:20 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 6
- Views: 272
Re: Bond Angles
If there are 4 regions of electron density with 3 of them being bonded pairs and one being lone pair, then the lone pair will create more repulsion, causing the bonded pairs to be pushed down, making their bonds closer together (so less than 109.5)
- Fri Dec 11, 2020 5:19 pm
- Forum: Polyprotic Acids & Bases
- Topic: Textbook 6C.19
- Replies: 7
- Views: 423
Re: Textbook 6C.19
HCl is a stronger acid because a strong acid is one that easily loses a proton/hydrogen. Cl has less electronegativity than F so the bond between H and Cl is weaker than that between H and F, making HCl the stronger acid. And for c, HClO2 is stronger because Cl has higher electronegativity than Br s...
- Fri Dec 11, 2020 5:15 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Relative Acidity
- Replies: 7
- Views: 291
Re: Relative Acidity
First compare bond length. If bonds are the same in the compounds you are comparing then compare stability of the anions (so compare electronegativity)
- Fri Dec 11, 2020 5:14 pm
- Forum: Hybridization
- Topic: hybridization
- Replies: 10
- Views: 708
Re: hybridization
It would be sp3 because there are 4 regions of electron density around the N (3 bonds with hydrogens and one lone pair)
- Sat Dec 05, 2020 2:12 pm
- Forum: Naming
- Topic: Textbook Question 9C.1
- Replies: 3
- Views: 206
Re: Textbook Question 9C.1
List the ligands in alphabetical order and add the suffix -ate when the complex has a negative charge
- Sat Dec 05, 2020 2:09 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Sapling Homework 9 Problem 2
- Replies: 10
- Views: 577
Re: Sapling Homework 9 Problem 2
use this list https://sites.google.com/site/chempendix/ligands to determine what type the ligand is.
- Sat Dec 05, 2020 2:08 pm
- Forum: Ionic & Covalent Bonds
- Topic: Polar and Nonpolar
- Replies: 37
- Views: 1678
Re: Polar and Nonpolar
Check to see if the dipoles cancel it. If they do, then the species is non polar and if they do not cancel out, the species is polar.
- Sat Dec 05, 2020 2:07 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Tetrahedral vs Square Planar Coordinate Complex
- Replies: 8
- Views: 459
Re: Tetrahedral vs Square Planar Coordinate Complex
For this class, you do not need to distinguish between tetrahedral and square planar. Just know that they are the common shape for coordination number 4.
- Sat Dec 05, 2020 2:06 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: coordination number
- Replies: 13
- Views: 740
Re: coordination number
Coordination number refers to the number of donor atoms from the ligands that are bonded to the central atom. To find this, determine what the ligands' types (mono dentate, bidentate, etc.) and based on this, count the number of atoms that are bonded to the centra atom. In [FeBr4]2 the coordination ...
Sapling
In the compound [Cd(en)Br2], what does the en stand for?
- Sat Dec 05, 2020 1:55 pm
- Forum: Naming
- Topic: Coordination Compound vs complex ion
- Replies: 4
- Views: 2629
Coordination Compound vs complex ion
What is the difference between a coordination compound and a complex ion? Is a complex ion just a coordination compound with a nonzero net charge.
- Sun Nov 29, 2020 11:40 pm
- Forum: Resonance Structures
- Topic: Resonance Structure Confusion
- Replies: 5
- Views: 440
Re: Resonance Structure Confusion
This is because the structures have different atom connectivities.
- Sun Nov 29, 2020 11:38 pm
- Forum: Significant Figures
- Topic: 40. versus 40
- Replies: 23
- Views: 1524
Re: 40. versus 40
Yes because, without a decimal present, ending zeros are not counted as significant digits
- Sun Nov 29, 2020 11:37 pm
- Forum: Sigma & Pi Bonds
- Topic: Pi and Sigma bonds
- Replies: 4
- Views: 188
Re: Pi and Sigma bonds
Sigma bonds are single bonds whereas pi bonds occur in any bonds other than single bonds. Sigma bonds are more flexible whereas pi bonds are more fixed in their positions.
- Sun Nov 29, 2020 11:35 pm
- Forum: Hybridization
- Topic: Sigma and Pi bonds
- Replies: 29
- Views: 2589
Re: Sigma and Pi bonds
Sigma bonds are more flexible and are single bonds whereas pie bonds are more fixed in their position and occur in double and triple bonds.
- Sun Nov 29, 2020 11:33 pm
- Forum: Resonance Structures
- Topic: Resonance
- Replies: 11
- Views: 634
Re: Resonance
This is because different resonance structures may have atoms with higher or lower formal charges. The resonance structure that is most stable is the one with atoms with the lowest magnitude of formal charge.
- Sun Nov 29, 2020 11:32 pm
- Forum: Hybridization
- Topic: Delocalized Pi Bond
- Replies: 10
- Views: 769
Re: Delocalized Pi Bond
Delocalized pie bonds occur when pie orbitals extend across more than 2 atoms in a molecule. In terms of lewis structures, you can show this by drawing multiple resonance structures.
- Tue Nov 24, 2020 1:51 am
- Forum: Lewis Structures
- Topic: Octet Rule
- Replies: 17
- Views: 1016
Re: Octet Rule
Atoms that are in the 3rd row or lower can have more than 8 electrons because they can fill their d states with electrons.
- Tue Nov 24, 2020 1:50 am
- Forum: Resonance Structures
- Topic: Atom Connectivities
- Replies: 5
- Views: 457
Re: Atom Connectivities
It means that the atoms are not being moved but rather it is the actual electrons that are delocalized/move to create different resonance structures.
- Tue Nov 24, 2020 1:49 am
- Forum: Lewis Structures
- Topic: Dot stucture
- Replies: 11
- Views: 505
Re: Dot stucture
Yes! And once you have found the total number of electrons, try to make each atom achieve an octet. If the central atom is in the 3rd group or lower, however, it can get an extended octet and have more than 8 electrons around it
- Tue Nov 24, 2020 1:46 am
- Forum: Quantum Numbers and The H-Atom
- Topic: Silver Electron Configuration
- Replies: 9
- Views: 2711
Re: Silver Electron Configuration
This is because the species is more stable if all of the orbitals in the d state are filled with 2 electron so an electron from the 5s state will move to the 4d state
- Tue Nov 24, 2020 1:44 am
- Forum: Electronegativity
- Topic: determining electronegativity
- Replies: 40
- Views: 5563
Re: determining electronegativity
Electronegativity is essentially an atom's pull on electrons. The trend is that electronegativity increases as you go across a period and decreases as you go down a group
- Tue Nov 24, 2020 1:42 am
- Forum: Dipole Moments
- Topic: Polarity
- Replies: 30
- Views: 1268
Re: Polarity
If the dipoles of the polar bonds cancel each other out, then the overall species would still be considered non polar.