Search found 140 matches
- Sat Mar 14, 2020 11:34 pm
- Forum: Second Order Reactions
- Topic: 1st order vs 2nd order graphs
- Replies: 2
- Views: 207
Re: 1st order vs 2nd order graphs
Second order has a negative slope because it is 1/[A] over time. As [A] is the reactant concentration, by decreasing over time, the second order graph increases because 1/[A] becomes bigger over time.
- Sat Mar 14, 2020 11:30 pm
- Forum: Van't Hoff Equation
- Topic: Celcius vs Kelvin for T1 and T2
- Replies: 84
- Views: 6444
Re: Celcius vs Kelvin for T1 and T2
I say stick to Kelvin because that is typically what we use. Plus in most equations, the gas constant is in the equation which is 8.314 J/(K * mol).
- Sat Mar 14, 2020 11:28 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat released/ gained
- Replies: 22
- Views: 936
Re: Heat released/ gained
When a bond is broken, energy is required because it takes energy to break bonds. Similarly, energy is released when bonds are formed.
- Sat Mar 14, 2020 11:25 pm
- Forum: First Order Reactions
- Topic: First order vs zero-order
- Replies: 4
- Views: 388
Re: First order vs zero-order
They are not the same precisely because of the y-axis. Because they are the integrated rate laws, they are supposed to be linear. They have to follow the y = mx+b format. As a result, the slope = -k, but the y axis are different: first order is ln[A] and zero order [A]. You could tell which order re...
- Sat Mar 14, 2020 11:17 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Pre-Equilibrium Approach
- Replies: 2
- Views: 302
Pre-Equilibrium Approach
What is this pre-equilibrium approach? How does this affect the rate law of a reaction?
- Sat Mar 14, 2020 10:48 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Endgame Q.9
- Replies: 1
- Views: 127
Endgame Q.9
I know we had to use Nernst equation, but what was the point of mention "3 moles of A(s)"? Was that supposed to trick us?
- Sat Mar 14, 2020 10:45 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Catalysts
- Replies: 3
- Views: 284
Catalysts
If given the reaction mechanisms, how can you identify if a catalyst was involved?
- Sun Mar 08, 2020 10:29 pm
- Forum: General Rate Laws
- Topic: Changing the mass of electrodes
- Replies: 6
- Views: 356
Changing the mass of electrodes
In Test 2, there was a problem that asked me what happens to the E(cell) if the mass of the anode is halved. What does happen to E(cell) if you change the mass or concentration of the electrode?
- Sun Mar 08, 2020 10:25 pm
- Forum: General Rate Laws
- Topic: arrhennius question
- Replies: 4
- Views: 278
Re: arrhennius question
The Arrhenius equation is used to find the rate constant at a different temperature. It shows the rate constant’s dependence on temperature.
- Sun Mar 08, 2020 10:21 pm
- Forum: General Rate Laws
- Topic: Rate constant vs. rate
- Replies: 4
- Views: 277
Re: Rate constant vs. rate
Rate constant is the comparative rates of reaction and product while rate is the measurement of how fast or slow a reaction occurs. A rate constant only changes with temperature but rate is affected by change in k or concentration.
- Sun Mar 08, 2020 10:06 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagrams
- Replies: 6
- Views: 401
Re: Cell Diagrams
If states are the same, you use a comma to separate the elements. If the elements are in different states use a vertical line.
- Sun Mar 08, 2020 10:04 pm
- Forum: Balancing Redox Reactions
- Topic: Why do we flip E for oxidation?
- Replies: 13
- Views: 1071
Re: Why do we flip E for oxidation?
Because all the E potentials are given as reduction values. You have to flip this value to get the oxidation value.
- Sun Mar 01, 2020 10:37 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Degree symbol
- Replies: 10
- Views: 954
Re: Degree symbol
(knot) just means that the E or Gibbs free energy are at standard conditions. So 25 degrees C, 1 atm, and 1.0 M.
- Sun Mar 01, 2020 10:35 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cathode/Right & Anode/Left
- Replies: 7
- Views: 991
Re: Cathode/Right & Anode/Left
Generally, that's what we assume the cathode and anode to be. If not, you would need to see the oxidation numbers to figure out which reaction is which.
- Sun Mar 01, 2020 10:33 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Nernst equation and ph
- Replies: 2
- Views: 214
Re: Nernst equation and ph
We know pH as the -log[H+].
Since Q is [products]/[reactants], we assume H+ to be a product.
For the Nernst equation, instead of E(knot) - (RT/nF)lnQ, we would use E(knot) - (0.0592/n)logQ.
Since Q is [products]/[reactants], we assume H+ to be a product.
For the Nernst equation, instead of E(knot) - (RT/nF)lnQ, we would use E(knot) - (0.0592/n)logQ.
- Sun Mar 01, 2020 10:28 pm
- Forum: Balancing Redox Reactions
- Topic: Reducing Agent
- Replies: 5
- Views: 413
Re: Reducing Agent
Yes, reducing agents are the ones that causes another substances to reduce (the substance oxidizes) and oxidizing agents are the ones that causes substances to be oxidized (the substance reduces).
- Sun Mar 01, 2020 10:22 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Test 2
- Replies: 4
- Views: 286
Re: Test 2
He is probably going to give us a list of half reactions and make us use only some of them. So yes, we would probably need to search for them on a table.
- Sun Mar 01, 2020 10:21 pm
- Forum: General Rate Laws
- Topic: Half Lives
- Replies: 3
- Views: 259
Half Lives
Can we use half lives to determine the time at which concentrations decreased by 1/4 instead of 1/2? Subsequently, what about decreasing to only 1/4 or 1/8 concentration? If so for the latter, do we take the half life, then take it once more? or do we multiply the half life by something?
- Sun Mar 01, 2020 10:17 pm
- Forum: General Rate Laws
- Topic: Differential Rate Law
- Replies: 3
- Views: 284
Differential Rate Law
What do we use the differential rate laws for? I know integrated rate laws are for concentration vs time, but when do we use the differential ones?
- Tue Feb 25, 2020 1:20 am
- Forum: Balancing Redox Reactions
- Topic: 6K.1
- Replies: 2
- Views: 205
6K.1
The following redox reaction is used in acidic solution in the Breathalyzer test to determine the level of alcohol in blood: H+ (aq) + Cr2O7^2- (aq) + C2H5OH(aq) ---> Cr^3+ (aq) + C2H4O(aq) + H2O(l) Identify the elements undergoing oxidation or reduction and indicate their initial and final oxidatio...
- Tue Feb 25, 2020 1:13 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Gibbs free energy and 6L.1
- Replies: 3
- Views: 255
Gibbs free energy and 6L.1
In the equation deltaG = -nFE, how do we figure out the n (if its moles of electrons).
For example, in part a 2Ce^+4(aq) + 3I^-(aq) + 2Ce^3+(aq) + I3^-(aq), Ecell° 5 11.08 V
How do I find the n in the equation?
For example, in part a 2Ce^+4(aq) + 3I^-(aq) + 2Ce^3+(aq) + I3^-(aq), Ecell° 5 11.08 V
How do I find the n in the equation?
- Sun Feb 23, 2020 10:27 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Vant Hoff Equation
- Replies: 9
- Views: 694
Re: Vant Hoff Equation
The Van't Hoff equation relates the change in equilibrium constant (K) and to a change in temperature, given that deltaH and deltaS are constant.
- Sun Feb 23, 2020 10:23 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: cell diagrams Pt
- Replies: 2
- Views: 103
Re: cell diagrams Pt
We had Pt because a metal is needed as an electrode for the cell diagram to proceed. As it is a solid conductor, Pt is chosen because it is inert (not changed in reaction but helps with reduction or oxidation).
- Sun Feb 23, 2020 10:20 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: G(not) and G
- Replies: 15
- Views: 699
Re: G(not) and G
G(not) is the standard Gibbs Free energy. So it's the energy in standard conditions. (1 M, 1atm, 25 degrees Celsius)
G is Gibbs Free energy in other conditions
G is Gibbs Free energy in other conditions
- Sun Feb 23, 2020 10:18 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagram to reaction
- Replies: 1
- Views: 110
Cell Diagram to reaction
From a cell diagram, how can you reverse back to the half reactions if both reactants and products are same states? And to that end, can we also figure out voltage from the diagram?
- Sun Feb 23, 2020 10:13 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagram
- Replies: 1
- Views: 99
Cell Diagram
In the salt bridge of the cell diagram, does the salt have to have the same charge as the electrodes for the ions to flow continuously? And would the E(not) of the diagram change if we change the conductors (the alligator clips and which they connect to)?
- Sun Feb 23, 2020 10:01 pm
- Forum: Balancing Redox Reactions
- Topic: Basic solutions
- Replies: 2
- Views: 173
Re: Basic solutions
In a basic solution, bases dissolve into OH- ions, so balancing these reactions require OH-. We would add OH- ions to whichever side that has H+ ions, so that water can form. 1. Separate half reactions. 2. Balance elements that aren't O or H 3. Balance O by adding H2O 4. Balance H by adding H+ 5. Ba...
- Sun Feb 23, 2020 9:55 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Concentration and Cell Potential
- Replies: 5
- Views: 2843
Re: Concentration and Cell Potential
Concentration affects cell potential because of Le Chatelier's principle. An increase in concentration in one of the reactants causes the reaction to proceed right to make more products. This means a higher positive voltage being produced.
- Sun Feb 23, 2020 9:51 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Nernst
- Replies: 7
- Views: 495
Re: Nernst
In the Nernst equation, E = E(not) - (RT/nF)lnQ.
E(not) is the standard cell potential
R is the gas constant (8.314 J/K mol)
T is temperature (in Kelvin)
n is the moles of electrons transferred
F is Faraday's constant . (96485 C/mol)
Q is the concentration of products over concentration of reactants
E(not) is the standard cell potential
R is the gas constant (8.314 J/K mol)
T is temperature (in Kelvin)
n is the moles of electrons transferred
F is Faraday's constant . (96485 C/mol)
Q is the concentration of products over concentration of reactants
- Mon Feb 17, 2020 10:31 pm
- Forum: Balancing Redox Reactions
- Topic: Electrical energy and Chemical energy
- Replies: 2
- Views: 203
Electrical energy and Chemical energy
Why is it that chemical energy and electrical energy can turn into one another?
- Mon Feb 17, 2020 10:25 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: deltaG in relation to K
- Replies: 3
- Views: 169
deltaG in relation to K
Can someone explain the part about K being less than or equal to 1? I understand that when deltaG is positive, it's spontaneous and if negative, nonspontaneous, but does that have anything to do with the sign of deltaS and deltaH?
- Mon Feb 17, 2020 10:21 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Van't Hoff part 2 [ENDORSED]
- Replies: 1
- Views: 49
Van't Hoff part 2 [ENDORSED]
If we are given deltaS and deltaH in nonstandard conditions, can we still use the Van't Hoff equation?
- Mon Feb 17, 2020 10:19 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Van't Hoff
- Replies: 6
- Views: 283
Van't Hoff
For the Van't Hoff equation, I know we use it to find K at different temperature, but does pressure matter or affect this equation?
- Mon Feb 17, 2020 10:16 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation numbers [ENDORSED]
- Replies: 4
- Views: 314
Oxidation numbers [ENDORSED]
Can someone explain how to figure out oxidation numbers? Like with the example Professor Lavelle used during class on Friday.
- Mon Feb 10, 2020 3:03 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Missing Calculator
- Replies: 1
- Views: 85
Missing Calculator
Hi guys, I know this is not a chemistry question but has anyone seen my calculator? It’s a Casio. I accidentally left it today at the 1 pm lecture. I sat in the middle row, around the 3rd seat to the front. Please tell me if you guys found it.
- Sun Feb 09, 2020 10:36 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Intensive
- Replies: 8
- Views: 474
Re: Intensive
Entropy is actually an extensive property, where the value depends on size or mass. Intensive means the value does not depend on the size.
- Sun Feb 09, 2020 10:33 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Gas v Liquids
- Replies: 4
- Views: 209
Re: Gas v Liquids
Gases have a higher entropy than liquids because they have a higher number of microstates. They occupy a greater volume than liquids and can move at greater speeds. As a result, they can occupy different positions and arrangements.
- Sun Feb 09, 2020 10:31 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: mCdeltaT
- Replies: 3
- Views: 135
mCdeltaT
Under what conditions would we use q=mCdeltaT? and for q=-q, does the phase of the substance matter? Or do we have to calculate both the change in temperature and the phase change?
- Sun Feb 09, 2020 10:22 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Specific Heat Capacity
- Replies: 5
- Views: 156
Specific Heat Capacity
When do we use specific heat capacity? And what equations would use this instead of molar heat capacity or even heat capacity in general?
- Sun Feb 09, 2020 10:12 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: qp=deltaH
- Replies: 6
- Views: 353
Re: qp=deltaH
At constant pressure, q (heat) equals delta H (the change in enthalpy).
- Sun Feb 02, 2020 11:35 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Open/Closed/Isolated System
- Replies: 3
- Views: 92
Re: Open/Closed/Isolated System
No, transfer of mass isn't allowed because mass is conserved within the boundaries of the system. Since heat or light aren't physical, they are allowed to transfer outside the system.
- Sun Feb 02, 2020 11:32 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: First Law
- Replies: 5
- Views: 323
Re: First Law
internal energy of a system refers to the sum of potential energy of the system along with kinetic energy.
- Sun Feb 02, 2020 11:16 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: p248
- Replies: 3
- Views: 136
Re: p248
isothermal expansion is where there is no change in temperature, temperature stays constant. In an ideal gas, the internal energy equal (3/2)nRT. From that, the change in internal energy is (3/2)nR(deltaT) because n and R are both constants. With deltaU also being q+w, we can say q+w=(3/2)nR(deltaT)...
- Sun Feb 02, 2020 11:00 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: 4C.1
- Replies: 2
- Views: 109
Re: 4C.1
Molar heat capacity is affected by molar mass. NO2 has a higher molar heat capacity because it is a larger molecule due to being bonded with 2 oxygen molecules instead of 1 like NO. Along with that, NO2 has a higher molar mass than NO.
- Sun Feb 02, 2020 10:51 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Week 4 lecture 3 calculating W question
- Replies: 2
- Views: 135
Re: Week 4 lecture 3 calculating W question
Microstates are a part of the Boltzmann equation. Microstates (W) is the number of ways in a system for energy of molecules to be arranged. In the example given, there are two atoms with two same energy states. Therefore, there are 4 different ways (micro states) of arranging the energy of the atoms...
- Sun Feb 02, 2020 10:44 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Irreversible vs Reversible
- Replies: 1
- Views: 38
Re: Irreversible vs Reversible
The main difference between irreversible and reversible expansion work is that the irreversible doesn't remain in thermodynamic equilibrium while reversible does. In reversible, the external and internal pressures of the system are equal throughout the process. In irreversible, there's a difference ...
- Sun Feb 02, 2020 10:38 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Volume and enthalpy
- Replies: 1
- Views: 84
Re: Volume and enthalpy
If the volume is constant, q (heat/enthalpy) equals the change in internal energy of the system (deltaU). Despite that, change in enthalpy equals deltaU + V(deltaP), because no work is being done on the system due to that constant volume.
- Sun Jan 26, 2020 5:33 pm
- Forum: Phase Changes & Related Calculations
- Topic: Steam Burns
- Replies: 9
- Views: 627
Re: Steam Burns
How is it that at 100C, both liquid and gas can exist at the same time? And why does steam require more energy to be converted?
- Sun Jan 26, 2020 5:31 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bond Enthalpies
- Replies: 3
- Views: 229
Re: Bond Enthalpies
Bond enthalpies can be used to calculate the net enthalpy change.
For the reactants, bond energies are positive because it takes energy for bonds to break. For products, energy is negative because when bonds form, energy is released. We then add all the energy values to gain the net enthalpy change.
For the reactants, bond energies are positive because it takes energy for bonds to break. For products, energy is negative because when bonds form, energy is released. We then add all the energy values to gain the net enthalpy change.
- Sun Jan 26, 2020 5:07 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bond Enthalpies
- Replies: 2
- Views: 46
Bond Enthalpies
Are bond enthalpies always given to us or do we have to figure them out? Also, does the amount of bonds being formed or broken matter when calculating the overall enthalpy change? For example, if 2 bonds of C-H were formed in a reaction, do we multiply its’ bond enthalpy by 2? And do coefficients ma...
- Sun Jan 26, 2020 4:57 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Standard enthalpy of solids and liquids
- Replies: 2
- Views: 57
Standard enthalpy of solids and liquids
Do solids and liquids have standard enthalpies of formations?
- Sun Jan 26, 2020 4:45 pm
- Forum: Phase Changes & Related Calculations
- Topic: Steam vs Water
- Replies: 4
- Views: 178
Steam vs Water
So in lecture, Professor Lavelle describes why steam causes severe burns compared to boiling water using a chart. Can someone explain the reasoning?
- Sun Jan 26, 2020 2:57 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ka &kb
- Replies: 2
- Views: 82
Re: ka &kb
Ka and Kb relate to pH and pOH from Kw.
Kw = Ka * Kb
With that, Kw = [H30+][OH-]
pH = -log[H30+] while pOH=-log[OH-]
Kw = Ka * Kb
With that, Kw = [H30+][OH-]
pH = -log[H30+] while pOH=-log[OH-]
- Sun Jan 19, 2020 11:46 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kw
- Replies: 2
- Views: 107
Kw
When do we use the Kw value?
- Sun Jan 19, 2020 11:44 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Q
- Replies: 6
- Views: 326
Re: Q
Q is the reaction quotient and is calculated at any time during a reaction. Q will change as time passes. Q and K are similar except that K is the value when the reaction is at equilibrium. If Q>K, the reverse reaction is favored, and if Q<K, the forward reaction is favored. IF Q=K, the both reverse...
- Sun Jan 19, 2020 11:41 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5% rule
- Replies: 2
- Views: 113
Re: 5% rule
If the change value, x, divided over the initial concentration is less than 5% of that initial, it's safe to assume that the change was negligible. This is to affirm that when we have a quadratic equation, we don't have to do the quadratic formula to solve for x.
- Sun Jan 19, 2020 11:38 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Combining Reactions
- Replies: 3
- Views: 139
Re: Combining Reactions
If both of those reactions are combined and form the third reaction, then we can add them. As a result, the K values can be multiplied together to find the K value of the third reaction.
- Sun Jan 19, 2020 11:34 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Ice Tables
- Replies: 4
- Views: 121
Ice Tables
When do we use ICE tables? I assumed it was when we had to find concentrations of the products, given K and the initial concentration(s).
- Sun Jan 19, 2020 11:29 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Le Chatelier Principle
- Replies: 4
- Views: 225
Le Chatelier Principle
Why does only a change in temperature affect K and not pressure or concentration? How does Le Chatelier principle apply to this if the principle sees the direction of the reaction due to changes?
- Sun Jan 19, 2020 11:02 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: pKa and pH
- Replies: 1
- Views: 79
pKa and pH
Is there a relationship between pKa and pH? If so, what is it?
- Sun Jan 12, 2020 3:33 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: 5J.13
- Replies: 4
- Views: 98
Re: 5J.13
Do we not have to calculate anything?
- Sun Jan 12, 2020 3:09 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: 5J.13
- Replies: 4
- Views: 98
5J.13
A gaseous mixture consisting of 2.23 mmol N2 and 6.69 mmol H2 in a 500.-mL container was heated to 600. K and allowed to reach equilibrium. Will more ammonia be formed if that equilibrium mixture is then heated to 700. K? For N2(g) + 3H2(g) <---> 2NH3(g), K=1.7x10^-3 at 600.K and 7.8x10^-5 at 700. K...
- Sun Jan 12, 2020 2:34 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE tables
- Replies: 1
- Views: 96
ICE tables
When doing the ICE tables, do we only use concentration of the reactions? What if we are given partial pressures?
- Thu Jan 09, 2020 1:06 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5G. 3
- Replies: 5
- Views: 151
5G. 3
Write the expression for K for each of the following reactions: (A) 2C2H4(g) + O2(g) + 4HCl(g) <—> 2C2H4Cl2(g) + 2H2O(g) Why is it that we write K for this problem using pressure yet for 5G.7 where we essentially do the same thing after balancing the reaction, they use Kc for the problem. Which is c...
- Wed Jan 08, 2020 10:15 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Liquids in Equilibrium Constant
- Replies: 3
- Views: 142
Liquids in Equilibrium Constant
Why are liquids not included in the equilibrium constant? Do we only included gases within K?
- Mon Jan 06, 2020 4:47 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium Constant
- Replies: 4
- Views: 105
Equilibrium Constant
What does the value of K supposed to tell us about the reaction? And what does strongly favor mean within equilibrium?
- Sun Dec 08, 2019 3:08 am
- Forum: Naming
- Topic: NH4[PtCl3(NH3)]
- Replies: 6
- Views: 832
NH4[PtCl3(NH3)]
The name is Ammonium amminetrichloridoplatinate(II). Why is it platinate and not platinum?
- Sun Dec 08, 2019 2:42 am
- Forum: Naming
- Topic: [Fe(OH)(OH2)5]Cl2
- Replies: 3
- Views: 2507
[Fe(OH)(OH2)5]Cl2
So the name for [Fe(OH)(OH2)5]Cl2 is pentaaquahydroxidoiron(III) chloride. But how did they get the charge on iron? And why is it chloride if there are two chloride, shouldn't it be dichloride?
- Sun Dec 08, 2019 2:27 am
- Forum: Naming
- Topic: Polydentate
- Replies: 2
- Views: 192
Polydentate
How can you tell a ligand is a polydentate? And what are examples of anionic ligands, how are they different from anions?
- Sat Dec 07, 2019 8:37 pm
- Forum: Lewis Acids & Bases
- Topic: Bronsted vs Lewis Acid
- Replies: 1
- Views: 174
Bronsted vs Lewis Acid
How can you tell if an acid is a Bronsted acid or a lewis acid? Can an acid be considered both or does it have to be or the other?
- Sun Dec 01, 2019 11:35 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Oxoacids
- Replies: 1
- Views: 114
Oxoacids
Why are oxoacids more readily lose H+ ions? And what are "oxoacids"?
- Sun Dec 01, 2019 11:28 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: relationship between pH and pOH
- Replies: 2
- Views: 251
relationship between pH and pOH
Can we calculate the pOH from pH? What is their relationship?
- Sun Dec 01, 2019 11:27 pm
- Forum: Amphoteric Compounds
- Topic: Amphoteric compounds
- Replies: 1
- Views: 79
Amphoteric compounds
What are amphoteric compounds? What does it mean "amphoteric oxides"?
- Sun Dec 01, 2019 11:25 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Anion stability
- Replies: 6
- Views: 449
Anion stability
How do we know if an anion is stable? And what is Ka value?
- Sun Dec 01, 2019 11:23 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: pOH
- Replies: 3
- Views: 111
pOH
When do we need to find pOH and why would be beneficial to find it?
- Mon Nov 25, 2019 12:01 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: What is a chelating complex?
- Replies: 1
- Views: 98
Re: What is a chelating complex?
Yes, it is essentially a complex that contains the ligand and forms a ring of atoms that includes the central metal atom.
Re: -dentate
Polydentates refers to a ligand molecule with more than one donor atom.
Bidentates have two atoms that can bond to a central atom or ion.
Ambidentate are like monodentates where they have one atom that can bond to a central atom or ion, but can do it at two possible locations.
Bidentates have two atoms that can bond to a central atom or ion.
Ambidentate are like monodentates where they have one atom that can bond to a central atom or ion, but can do it at two possible locations.
- Sun Nov 24, 2019 11:54 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular shape of carbon Dioxide
- Replies: 10
- Views: 579
Re: Molecular shape of carbon Dioxide
It is linear as it has 16 valence electrons. The carbon does not have lone pairs and forms double bonds with the oxygens. So it would be AX2.
- Sun Nov 24, 2019 11:51 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: NH3
- Replies: 4
- Views: 323
NH3
Why is NH3 considered a neutral atom?
- Sun Nov 24, 2019 11:48 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Seesaw shape
- Replies: 5
- Views: 228
Re: Seesaw shape
Seesaw shape occurs when you have 4 atoms surrounding the central atom along with a lone pair. It would occur because during the trigonal bipyramidal, we would have three atoms in the planar, 120 degrees apart, and then an atom on the top and bottom of the central atom, making them 90 degrees from t...
- Sun Nov 24, 2019 11:37 pm
- Forum: Hybridization
- Topic: hybridization
- Replies: 3
- Views: 106
Re: hybridization
It means that the orbitals are not completely an s,p,d orbital. It is a mix of them, with a different energy and shape.
- Sun Nov 24, 2019 11:34 pm
- Forum: Hybridization
- Topic: 2F.5
- Replies: 3
- Views: 248
Re: 2F.5
a) sp
b) sp2
c) sp3
d) sp3
b) sp2
c) sp3
d) sp3
- Sun Nov 24, 2019 11:20 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: Dipole-Dipole
- Replies: 2
- Views: 243
Dipole-Dipole
When does a dipole-dipole intermolecular force occur?
- Sun Nov 24, 2019 11:18 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Cisplatin and Transplatin
- Replies: 2
- Views: 155
Cisplatin and Transplatin
How does Cisplatin stop cell division? Why doesn't Transplatin have the same effect when forming a coordinate compound with DNA?
- Sun Nov 17, 2019 11:56 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shape vs Electron Geometry
- Replies: 4
- Views: 382
Re: Molecular Shape vs Electron Geometry
Molecular shape excludes the electron lone pairs while electron geometry involves them.
- Sun Nov 17, 2019 11:36 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 9
- Views: 490
Re: Bond Angles
We got to memorize the basic angles like 90, 120, and 180 and we should be able to predict if they are greater than or less than these angles. We don’t need to know the unique ones. I just imagine what the molecule looks like in a 3D setting based on the name of the shape.
- Sun Nov 17, 2019 11:30 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shape
- Replies: 1
- Views: 89
Re: Molecular Shape
Lone pairs aren’t considered in identifying a molecules’ shape because they are not bonded to the atom. When lone pairs are around the central atom, the atoms bonded to it are forced to move due to the electron repulsion from the lone pairs.
- Sun Nov 17, 2019 11:24 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: IMF
- Replies: 3
- Views: 142
Re: IMF
Ion- dipole is between an ion and a polar molecule while dipole-dipole is between polar molecules.
- Sun Nov 17, 2019 11:17 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Repulsion Strength
- Replies: 5
- Views: 380
Repulsion Strength
Why is the electron repulsion strength stronger for lone-lone PR> lone-bonding PR> bonding-bonding PR?
- Sun Nov 17, 2019 11:11 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR Notation
- Replies: 4
- Views: 377
VSEPR Notation
Can someone re-explain how to write VSEPR notation? I did not write the notation at all during my notes.
- Sun Nov 10, 2019 11:39 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: London Dispersion Forces
- Replies: 1
- Views: 84
Re: London Dispersion Forces
London dispersion forces are the weakest of the intermolecular forces. I think they take priority in larger atoms because of more surface area to distort the electrons.
- Sun Nov 10, 2019 11:36 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: What’s the Difference
- Replies: 6
- Views: 520
Re: What’s the Difference
Polarizability is the tendency by the anion to be polarized by the cation and polarizing refers to the power of the cations to distort the electrons of the anion.
- Sun Nov 10, 2019 11:33 pm
- Forum: Bond Lengths & Energies
- Topic: Rankings
- Replies: 2
- Views: 107
Re: Rankings
There are bonds within a molecule like covalent and ionic bonds and bonds between molecules like london dispersion forces and hydrogen bonding. The intramolecular (covalent/ionic) are stronger than the latter (intermolecular).
- Sun Nov 10, 2019 11:31 pm
- Forum: Dipole Moments
- Topic: Dipole Moment vs Interactions
- Replies: 2
- Views: 97
Dipole Moment vs Interactions
How does a dipole moment differ from a dipole interaction? Is it possible for a molecule to have both? And also, what is ion-ion dipole?
- Sun Nov 10, 2019 11:18 pm
- Forum: Dipole Moments
- Topic: H Bonding
- Replies: 4
- Views: 258
H Bonding
Does H bonding only work with Fluorine, Oxygen, and Nitrogen? Why only them and not other elements? Why is this type of bonding not as strong as covalent bonding?
- Sun Nov 10, 2019 11:14 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: The spin of a quantum number
- Replies: 6
- Views: 504
Re: The spin of a quantum number
You can't really tell. You can say it's positive or negative but the other electrons in the other subshells have to have the same spin.
- Sun Nov 10, 2019 11:13 pm
- Forum: Dipole Moments
- Topic: Shape of Molecule
- Replies: 2
- Views: 200
Shape of Molecule
How does the shape of the molecule affect the strength of the dipole interactions? And why would it matter?
- Sun Nov 10, 2019 11:06 pm
- Forum: Dipole Moments
- Topic: Dipole Moment
- Replies: 6
- Views: 306
Dipole Moment
How do we know if a molecule has a dipole moment? And why does the arrow have to point to the lowercase delta positive?
- Sun Nov 03, 2019 11:46 pm
- Forum: Ionic & Covalent Bonds
- Topic: Covalent and Ionic Bonds
- Replies: 6
- Views: 311
Covalent and Ionic Bonds
Can someone explain the concept of a molecule having both ionic and covalent characters. How do we determine which is more?
- Sun Nov 03, 2019 11:38 pm
- Forum: Resonance Structures
- Topic: Drawing Resonance Structures on Test?
- Replies: 4
- Views: 202
Re: Drawing Resonance Structures on Test?
We have to indicate that it is the hybrid of all the resonance structures.