What is the show cesium and iodine love watching together?
CSI
Search found 106 matches
- Fri Mar 12, 2021 10:51 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3912231
- Fri Mar 12, 2021 10:50 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3912231
Re: Post All Chemistry Jokes Here
How about the chemical workers… are they unionized?
- Fri Mar 12, 2021 10:49 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Problem with change in temperature and pressure
- Replies: 5
- Views: 449
Problem with change in temperature and pressure
If you have a chemistry problem where a gas expands in volume AND temperature and were asked to calculate entropy, would you first solve the problem using the equation for two different volumes, and then assume volume is constant and calculate the entropy for two separate temperatures and add them?
- Fri Mar 12, 2021 10:45 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Shorthand with more than 4 molecules
- Replies: 2
- Views: 219
Shorthand with more than 4 molecules
Could someone please explain how you would read a shorthand notation for a voltaic cell that has more than 4 molecules in its notation.
- Wed Mar 10, 2021 1:52 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Strongest reducing metal
- Replies: 8
- Views: 494
Strongest reducing metal
How do you find the most strongly reducing metal when given a series of metals?
- Mon Mar 01, 2021 5:17 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3912231
Re: Post All Chemistry Jokes Here
What should you do if no one laughs at your chemistry jokes?
Keep telling them until you get a reaction.
Keep telling them until you get a reaction.
- Mon Mar 01, 2021 5:15 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3912231
Re: Post All Chemistry Jokes Here
What is the chemical formula for "banana"? BaNa2
- Mon Mar 01, 2021 5:15 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Sapling #15
- Replies: 3
- Views: 251
Re: Sapling #15
You should add the two values together since you flipped the sign for one of the half-reactions. Doing so will result in a positive voltage. Remembering that the voltage should always be positive helps remember which sign to make the reactions.
- Mon Mar 01, 2021 5:12 pm
- Forum: Zero Order Reactions
- Topic: Equation with dt
- Replies: 6
- Views: 561
Re: Equation with dt
All the equations with dt represents differential rate laws, where it depicts rate versus concentration, but the integrated rate law is what shows rate versus time.
- Mon Mar 01, 2021 5:11 pm
- Forum: First Order Reactions
- Topic: Half Life caluclations
- Replies: 6
- Views: 372
Re: Half Life caluclations
It is however many times you need to divide the larger concentration to get to the second one. You could see this up as [larger concentration]/ 2^x =[lower concentration], and solve for x.
- Wed Feb 24, 2021 12:13 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3912231
Re: Post All Chemistry Jokes Here
The optimist sees the glass half full.
The pessimist sees the glass half empty.
The chemist see the glass completely full, half in the liquid state and half in the vapor state.
The pessimist sees the glass half empty.
The chemist see the glass completely full, half in the liquid state and half in the vapor state.
- Wed Feb 24, 2021 12:09 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: textbook problem 5G.17
- Replies: 2
- Views: 253
Re: textbook problem 5G.17
The curves dont cross eachother since they have two different pressures at equillibrium.
- Wed Feb 24, 2021 12:04 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Using Pressure in a deltaS equation
- Replies: 4
- Views: 418
Re: Using Pressure in a deltaS equation
Since in PV=nRT, pressure and volume have an inverse relationship, so you can replace V2 and V1 with P2 and P1.
- Wed Feb 24, 2021 11:58 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: H vs q
- Replies: 20
- Views: 965
Re: H vs q
Q is the energy transfer due to thermal reactions such as heating water, cooking, etc. anywhere where there is a heat transfer. H, is the state of the system, the total heat content.
- Wed Feb 24, 2021 11:36 am
- Forum: Balancing Redox Reactions
- Topic: Acidic/Basic Conditions
- Replies: 3
- Views: 208
Re: Acidic/Basic Conditions
In order to balance a redox reaction, you would follow these steps: 1. Balance elements in the equation other than O and H. 2. Balance the oxygen atoms by adding H2O molecules to the opposite side of the equation. 3. Balance the hydrogen atoms by adding H+ ions. 4. Add up the charges on each side an...
- Thu Feb 18, 2021 4:57 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3912231
Re: Post All Chemistry Jokes Here
Have you heard the one about a chemist who was reading a book about helium? He just couldn't put it down.
- Thu Feb 18, 2021 4:56 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Constant Volume
- Replies: 15
- Views: 937
Re: Constant Volume
Cv and Cp are used when there are constant volume and constant pressure, respectively, when the temperature is changing. I believe you use the table which states CV an CP for either atoms, linear, or non-linear molecules.
- Thu Feb 18, 2021 4:51 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Reversible process total entropy
- Replies: 2
- Views: 192
Re: Reversible process total entropy
Would this mean that the delta S surroundings is -nRln (V2/V1) or -nRln (P2/P1) ?
- Thu Feb 18, 2021 4:49 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: 2nd Law
- Replies: 11
- Views: 734
Re: 2nd Law
This law is also what dignifies the statement delta S total= S surroundings +S system.
- Thu Feb 18, 2021 4:48 pm
- Forum: Calculating Work of Expansion
- Topic: work of expansion and constant pressure
- Replies: 3
- Views: 196
work of expansion and constant pressure
If the volume changes but is at constant pressure, does that automatically make the work of expansion w=-Px (delta) V?
- Wed Feb 10, 2021 6:59 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3912231
Re: Post All Chemistry Jokes Here
Silver walks up to Gold in a bar and says, "AU, get outta here!"
- Mon Feb 08, 2021 8:10 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Textbook problem 4D.9
- Replies: 1
- Views: 147
Re: Textbook problem 4D.9
To do this problem, you would need to convert 1 mole of TNT into grams, then use density to convert grams to cm cubed, then use the conversion that 1 L is =1000 cm^3. Divide -67 kj by this number and you would have enthalpy change per liter.
- Mon Feb 08, 2021 7:55 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Progress of Rxn Diagram
- Replies: 4
- Views: 276
Re: Progress of Rxn Diagram
This is correct since we know that if Q<K, the reaction will favor the products and therefore occur spontaneously since that is the way it moves toward. When Q is greater than K, the reaction will favor the reactants and therefore need the energy to move in the forward direction.
- Mon Feb 08, 2021 7:44 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Sapling Week 5/6 #8
- Replies: 1
- Views: 141
Sapling Week 5/6 #8
Calculate the standard molar entropy of vaporization of water at 28.0 °C, given that its standard molar entropy of vaporization at 100.0 °C is 109.0 J⋅K−1⋅mol−1 and the molar heat capacities at constant pressure for liquid water and water vapor are 75.3 J⋅K−1⋅mol−1 and 33.6 J⋅K−1⋅mol−1 , respectivel...
- Mon Feb 08, 2021 7:24 pm
- Forum: Calculating Work of Expansion
- Topic: All Equations So Far
- Replies: 2
- Views: 195
Re: All Equations So Far
This is kind of an expansion to the first post, but when exactly would you use each equation?
- Mon Feb 01, 2021 6:56 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Change in Internal Energy Formula
- Replies: 3
- Views: 234
Re: Change in Internal Energy Formula
The -P delta V equation is used when volume changes in an irreversible reaction, where the external pressure is constant I believe.
- Mon Feb 01, 2021 6:53 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3912231
Re: Post All Chemistry Jokes Here
What do chemists call a benzene ring with iron atoms replacing the carbon atoms? A ferrous wheel.
- Mon Feb 01, 2021 6:52 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: 2 deltaG equations
- Replies: 6
- Views: 498
Re: 2 deltaG equations
You could use both these equations when solving for the change in the equilibrium constant, Keq, of a chemical reaction given change in temperature, T, given the standard enthalpy change, ΔH⊖, for the process.
- Mon Feb 01, 2021 6:51 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: delta U versus delta H
- Replies: 5
- Views: 201
Re: delta U versus delta H
The formula for delta U has delta H in it, as it is delta U= deltaH -P(delta V)
- Mon Feb 01, 2021 6:50 pm
- Forum: Ideal Gases
- Topic: Textbook 5G.5
- Replies: 4
- Views: 127
Re: Textbook 5G.5
Since these images show the same flask over time, the reaction that would be at equilibrium would be the one that has the forward and backward reaction occurring at the same rate. Since the forward reaction increases the number of moles, we know that as time goes on the number of molecules increasin...
- Wed Jan 27, 2021 4:07 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3912231
Re: Post All Chemistry Jokes Here
H2O is water and H2O2 is hydrogen peroxide. What is H2O4?
Drinking.
Drinking.
- Wed Jan 27, 2021 4:06 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: How Kc and heat relate
- Replies: 1
- Views: 112
Re: How Kc and heat relate
A higher Kc means that the equilibrium ratio of products to reactants will be higher than at a lower Kc. Therefore it is said to "favor the right", since it has a greater proportion these products.
- Wed Jan 27, 2021 3:54 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Textbook Q 6E 1
- Replies: 4
- Views: 209
Re: Textbook Q 6E 1
Since H2SO4 is a polyprotic and strong acid, you can assume that the first deprotonation ionizes completely, which is why the ICE table directly plugs in the concentration for the second deprotonation .
- Wed Jan 27, 2021 3:51 pm
- Forum: Ideal Gases
- Topic: Calculating Gibbs free energy
- Replies: 2
- Views: 137
Re: Calculating Gibbs free energy
In a problem like this, you would use the equation delta (G)= -RTlnK + RTlnQ, where K is given, and Q is the formula we learned to use in equilibrium, where in this case would be ([P i]^2/ [Pi2])
- Wed Jan 27, 2021 3:47 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Reversible Reactions
- Replies: 1
- Views: 88
Reversible Reactions
In the lecture today, Dr. Lavelle mentioned that reversible reactions do more work than non-reversible ones. Could someone please explain why this is so?
- Wed Jan 20, 2021 3:38 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3912231
Re: Post All Chemistry Jokes Here
Why did the noble gas cry? Because all his friends argon.
- Wed Jan 20, 2021 3:34 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Hess Law
- Replies: 10
- Views: 1756
Re: Hess Law
You add up the values of the enthalpies and "cancel" out the reactants if those reactants are the same as those on the product side of another equation. If in case the coefficients are different, the equations can be combined algebraically. If one side of a reaction had say, 4H2 on the rea...
- Wed Jan 20, 2021 3:20 pm
- Forum: Phase Changes & Related Calculations
- Topic: Phase Change
- Replies: 5
- Views: 344
Re: Phase Change
I think that state is state property since it doesn't matter the pathway that the chemical takes to get to that phase.
- Mon Jan 18, 2021 3:45 pm
- Forum: Phase Changes & Related Calculations
- Topic: heat capacity at constant volume vs constant pressure
- Replies: 3
- Views: 142
Re: heat capacity at constant volume vs constant pressure
I think for an ideal gas at constant pressure, it takes more heat to achieve the same temperature change than it does at constant volume. At constant volume all the heat added goes into raising the temperature.But at constant pressure some of the heat goes to doing work.
- Mon Jan 18, 2021 3:43 pm
- Forum: Ideal Gases
- Topic: Hw Question #4
- Replies: 5
- Views: 296
Re: Hw Question #4
With gas pressures, you can still set up an ICE table since the K is given in Kp. It would be set up the same way as you would given molarity.
- Thu Jan 14, 2021 2:20 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3912231
Re: Post All Chemistry Jokes Here
Have you heard of Boyle's Law? It's a law stating that the pressure of a given mass of an ideal gas is inversely proportional to its volume at a constant temperature. Now building on top of that, have you ever heard of Cole's Law? It's a salad dish of raw cabbage, carrots, and other vegetables mixed...
- Thu Jan 14, 2021 2:17 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: pKA and pH
- Replies: 8
- Views: 254
Re: pKA and pH
I think pka ad pkb aren't necessarily equal to ph and pOH, but they both will add to 14. If you think about the way Lavelle explains how p is (-log), then we can see how [H30+][OH-]=10^-14 and [Ka][Kb]=10^-14.
- Thu Jan 14, 2021 10:16 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Textbook Problem 5J.5
- Replies: 2
- Views: 319
Re: Textbook Problem 5J.5
When the pressure is increased, the reaction is going to favor the side with fewer moles. This is because, by the equation PV=nRT, we see that an increase in pressure creates an increase in moles. In order to retain equilibrium, the reaction will favor the side with fewer moles. So no change should ...
- Tue Jan 12, 2021 11:35 am
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Video Module question 19
- Replies: 3
- Views: 89
Re: Video Module question 19
Since we need the concentration (M) for the equation, divide the number of moles by the 3 liters.
- Tue Jan 12, 2021 11:23 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Textbook 5G.9
- Replies: 3
- Views: 215
Re: Textbook 5G.9
I think this reasoning would be okay as well, since Le Chatilier's principle states that the reaction will always establish equilibrium again it would do so by forming more products. This results in more moles in the same volume, which by the PV=nrT equation shows that the pressure does increase.
- Fri Jan 08, 2021 3:18 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Textbook Problem 5J.11 Part D
- Replies: 3
- Views: 116
Re: Textbook Problem 5J.11 Part D
Knowing that breaking of bonds is an endothermic process, that means that heat is a reactant in the process. Therefore with a temperature increase, the system will shift towards where there is less heat, which is the product side.
- Fri Jan 08, 2021 3:15 pm
- Forum: Ideal Gases
- Topic: Bohr, Gay-Lussac, etc.
- Replies: 3
- Views: 197
Re: Bohr, Gay-Lussac, etc.
I think as long as you remember how to isolate each variable and solve it using the given information, you will be okay.
- Fri Jan 08, 2021 1:14 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Video Module Question 30 [ENDORSED]
- Replies: 3
- Views: 118
Re: Video Module Question 30 [ENDORSED]
With questions like this, it always helps me to immediately make sure all concentrations are given, so I always automatically convert given moles and grams to concentrations. Also, since there are no coefficients other than 1, after setting up the ICE table you would be able to solve an equation for...
- Tue Jan 05, 2021 2:16 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Q vs K
- Replies: 12
- Views: 637
Re: Q vs K
Something that helped me remember is that K is the constant of a certain reaction when it is in equilibrium, but Q is the same formula using products and reactants at any stage of a reaction.
- Mon Jan 04, 2021 3:46 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Problem 5G11
- Replies: 5
- Views: 303
Re: Problem 5G11
I believe the reaction quotient Q is the same as the Kc. There was a previous question that asked this on the chemistry community too from a while back, but it seems the reaction quotient Q follows the same rules where you do not take into account solids or liquids.
- Mon Jan 04, 2021 3:22 pm
- Forum: Ideal Gases
- Topic: Converting to Concentration and Pressure Values
- Replies: 7
- Views: 590
Re: Converting to Concentration and Pressure Values
Another way to think of it is to rearrange the variables in the equation. We know that moles/volume is concentration, so n/V in this case is concentration. Solving for n/V in PV=nrT shows that concentration is equal to P/(R*T)
- Mon Dec 07, 2020 12:20 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3912231
Re: Post All Chemistry Jokes Here
Why do chemists enjoy working with ammonia?
Because it's pretty basic stuff.
Because it's pretty basic stuff.
- Mon Dec 07, 2020 12:18 pm
- Forum: Conjugate Acids & Bases
- Topic: Conjugate Acids and Bases
- Replies: 4
- Views: 332
Re: Conjugate Acids and Bases
In general, a conjugate base is an anion that can absorb a proton in a chemical reaction. The conjugate acid is a cation that donates the proton or hydrogen in the reaction and loses the proton.
- Mon Dec 07, 2020 12:17 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: kbr?
- Replies: 3
- Views: 381
Re: kbr?
In general, I believe cations from group 1 and group 2 are considered weak lewis acids and do not generate H3O+, and does not affect the pH, making it nuetral.
- Mon Dec 07, 2020 12:15 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: weak acid/base and pH
- Replies: 9
- Views: 795
Re: weak acid/base and pH
If the salt has the anion of a weak acid, it will make the solution basic. If the salt has a cation of a weak base, it will make the solution acidic.
- Mon Dec 07, 2020 12:14 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Electronegativity/acidity
- Replies: 5
- Views: 343
Re: Electronegativity/acidity
If an acid has a more electronegative cation, the acid will more readily lose H+ ions. This is because the resulting anion is more stable, making the two parts ionize more easily, hence increasing the acidity.
- Mon Dec 07, 2020 12:12 pm
- Forum: Polyprotic Acids & Bases
- Topic: Protonated Acid
- Replies: 3
- Views: 259
Protonated Acid
In the lecture, Dr. Lavelle referred to protonated and alkaline solutions, what exactly does this mean?
- Tue Dec 01, 2020 2:59 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3912231
Re: Post All Chemistry Jokes Here
I asked the guy sitting next to me if he had any Sodium Hypobromite…
He said NaBrO
He said NaBrO
- Tue Dec 01, 2020 2:57 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: radial distribution function
- Replies: 2
- Views: 260
Re: radial distribution function
The radial distribution function is the probability distribution to find the center of a particle in a given position at a radial distance r from the center of a reference sphere. I just think the most important part of this concept it knowing that orbitals and wavefunctions are what give us the pro...
- Tue Dec 01, 2020 2:50 pm
- Forum: Limiting Reactant Calculations
- Topic: Stoichiometric Problem
- Replies: 6
- Views: 476
Re: Stoichiometric Problem
Hi bff so in the stoichiometric problem you would use the chemical equation to find ratios between any two molecules. From there you can use the ratio of moles to convert from moles to grams using molar mass.
- Tue Dec 01, 2020 2:38 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligands and Chelating Complexes
- Replies: 2
- Views: 163
Re: Ligands and Chelating Complexes
if ligands are bidentate or more they can form a chelate. I believe this means they bind at more than one site.
- Tue Dec 01, 2020 2:27 pm
- Forum: Coordinate Covalent Bonds
- Topic: mono, bi, tridentate
- Replies: 2
- Views: 273
mono, bi, tridentate
Is whether a ligand is mono, bi, or tri dentate dependent on how many lone pairs it has?
- Tue Dec 01, 2020 2:16 pm
- Forum: Hybridization
- Topic: identification
- Replies: 5
- Views: 353
Re: identification
hybrid orbitals have to do with the regions of electron density. In this case, the five regions of electron density mean the hybridization is sp3d.
- Tue Dec 01, 2020 1:52 pm
- Forum: Naming
- Topic: Ligand Names
- Replies: 3
- Views: 229
Re: Ligand Names
I think that we have to know the general formula of ligand names( with the greek prefix) with the transition metal cation and the anion hydrate.
- Wed Nov 25, 2020 8:14 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3912231
Re: Post All Chemistry Jokes Here
Two chemists go into a bar. The first one says "I think I'll have an H2O." The second one says "I think I'll have an H2O too" — and he died.
- Wed Nov 25, 2020 8:13 am
- Forum: Hybridization
- Topic: Hybridization Clarification
- Replies: 9
- Views: 603
Re: Hybridization Clarification
In lecture, Dr. Lavells referred to many "unhybridized orbitals". How exactly can you identify these?
- Wed Nov 25, 2020 8:11 am
- Forum: Electronegativity
- Topic: How is electronegativity calculated?
- Replies: 4
- Views: 307
Re: How is electronegativity calculated?
After looking into it, it looks like electronegativity cannot be calculated from the number of subatomic particles in an atom. However, using Ionization Energy and Electron Affinity, one can calculate the Electronegativity of an atom using the above equation.
- Wed Nov 25, 2020 8:02 am
- Forum: Lewis Structures
- Topic: Octet Rule
- Replies: 17
- Views: 1239
Re: Octet Rule
I had a follow-up question to this discussion thread, is there a maximum number of electrons an expanded octect can accommodate?
- Wed Nov 25, 2020 7:58 am
- Forum: Dipole Moments
- Topic: Dipole Moments Cancelling out
- Replies: 10
- Views: 1166
Re: Dipole Moments Cancelling out
It is also important to note that different electronegativities between elements indicate different "vector" lengths when drawing the dipole moments out. This could result in a net vector or dipole in one direction.
- Thu Nov 19, 2020 9:06 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: Hydrogen bonds and dipole-dipole
- Replies: 11
- Views: 1198
Hydrogen bonds and dipole-dipole
If a molecule has hydrogen bonds does it mean it has dipole-dipole as well?
- Thu Nov 19, 2020 6:02 pm
- Forum: Electronegativity
- Topic: Electronegativity Trends
- Replies: 12
- Views: 1192
Re: Electronegativity Trends
Kind of as a follow-up question, how would you determine which element in a molecule would create a bigger difference in electronegativity? Like when trying to compare two molecules' iconic character?
- Thu Nov 19, 2020 3:37 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3912231
Re: Post All Chemistry Jokes Here
What do you call a tooth in a glass of water? One molar solution
- Wed Nov 18, 2020 1:56 pm
- Forum: Hybridization
- Topic: 2.a.13 part d sappling
- Replies: 2
- Views: 193
2.a.13 part d sappling
I had a question that came up as I was doing one of the textbook problems. I noticed that the first electron taken out of Cu to become an ion is taken from 4s. Why is this the case, if the electron configuration of NI is [Ar], 3d8, 4s2?
- Mon Nov 16, 2020 5:31 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shape generalities
- Replies: 4
- Views: 270
Re: Molecular Shape generalities
It isn't always the same, but I have found that usually when a molecule has the same number of electron densities it becomes easy to assume a shape. For example, when an atom has 4 electron densities around it and no lone pairs, the shape is tetrahedral. When there is one lone pair, the topmost atom...
- Mon Nov 16, 2020 5:24 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3912231
Re: Post All Chemistry Jokes Here
Why was the mole of oxygen molecules excited when he walked out of the singles bar?
He got Avogadro's number.
He got Avogadro's number.
- Fri Nov 13, 2020 8:35 pm
- Forum: Sigma & Pi Bonds
- Topic: Triple bond?
- Replies: 21
- Views: 950
Re: Triple bond?
So just to clarify, as the bond numbers increase (etc. single to triple), the number of sigma bonds stay the same and pi and delta increase?
- Fri Nov 13, 2020 8:33 pm
- Forum: Octet Exceptions
- Topic: Octet Rule Exceptions
- Replies: 20
- Views: 1493
Re: Octet Rule Exceptions
I believe that any elements past the atomic number 10 can have an expanded octect. This is because we see that when there are 5 or 6 groupson the central atom, d- orbitals are involved which allow octects to expand.
- Fri Nov 13, 2020 8:31 pm
- Forum: Dipole Moments
- Topic: Dipole dipole vs LDF
- Replies: 10
- Views: 3505
Re: Dipole dipole vs LDF
LDF happens between all molecules I believe, but dipole dipole will happen between polar ones. LDF only happens when symmetric molecules bind or molecules of the same molecular formula bind.
- Mon Nov 09, 2020 4:13 pm
- Forum: Bond Lengths & Energies
- Topic: Sapling #4 Bond Length
- Replies: 2
- Views: 95
Re: Sapling #4 Bond Length
To add on to the previous comment, I believe you would be able to tell which experimentally derived bond length fits which atom because the length is usually in between the single and double bond lengths, as in the example with CH above.
- Mon Nov 09, 2020 4:09 pm
- Forum: Dipole Moments
- Topic: Polarity
- Replies: 3
- Views: 180
Re: Polarity
I believe if the difference in electronegativity for the atoms in a bond is greater than 0.4, we consider the bond polar. If the difference in electronegativity is less than 0.4, the bond is essentially nonpolar. If the electronegativity difference is greater than 2 it is considered ionic, and if it...
- Sun Nov 08, 2020 9:02 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Distortion
- Replies: 8
- Views: 258
Re: Distortion
I think the reason anions that are pulled into the shared region are classified as covalent is because a covalent bond indicates that two electrons are being shared by two molecules and unlike an ionic bond, are completely transferred over to the other molecule. In the shared region, the two electro...
- Thu Nov 05, 2020 5:23 pm
- Forum: Lewis Structures
- Topic: Sapling Week5/6 Q3
- Replies: 5
- Views: 293
Re: Sapling Week5/6 Q3
You could start this by drawing out the lewis structures for the nitrite, nitrate, phosphite, and phosphate ions. Nitrite has the formula NO2, which when drawn out without minimizing formal charges, would have single bonds between both Os and the N, leaving a formal charge of -1 on both Os and a for...
- Thu Nov 05, 2020 5:16 pm
- Forum: Octet Exceptions
- Topic: Identifying Radicals
- Replies: 24
- Views: 1307
Re: Identifying Radicals
I believe that if there ever if one electron that is not paired in a molecule it would be considered a radical.
- Mon Nov 02, 2020 1:23 pm
- Forum: Octet Exceptions
- Topic: Sulfur Octet Exception
- Replies: 2
- Views: 184
Re: Sulfur Octet Exception
Just for further explanation, for atoms in the fourth period and beyond, higher d orbitals can be used for additional shared pairs beyond the octet. The energetic cost of using these higher orbitals to accommodate bonding electrons becomes smaller, as shown by the different atomic orbital energies.
- Mon Nov 02, 2020 1:15 pm
- Forum: Lewis Structures
- Topic: Different Lewis Structures
- Replies: 6
- Views: 353
Different Lewis Structures
If two resonance structures have a mirror image of eachother (have the same outer atoms connected to it), are they still considered two different resonance structures or can they be considered the same?
- Fri Oct 30, 2020 10:08 am
- Forum: Quantum Numbers and The H-Atom
- Topic: Principal quantum number
- Replies: 2
- Views: 182
Re: Principal quantum number
Another trend like this is seen in the l subshells, as you can find the number of subshells using 2l+1. For example, when l is 1, there are three subshells(2*1+1), -1, 0 and 1. when l is 2, there are five subshells(2*2+1), -2,-1, 0 and 1 and 2.
- Wed Oct 28, 2020 4:29 pm
- Forum: Trends in The Periodic Table
- Topic: Atomic Radius
- Replies: 30
- Views: 3222
Re: Atomic Radius
An easy way to remember it is that as you go down a group, additional levels of shells are added, which adds tangible size to the atom. Across a period, the atomic radii decreases because as more electrons are added in the same shell, the effective nuclear charge, or Zeff, increases. This is the opp...
- Wed Oct 28, 2020 4:26 pm
- Forum: Ionic & Covalent Bonds
- Topic: Is ionic or covalent stronger?
- Replies: 31
- Views: 17041
Re: Is ionic or covalent stronger?
Ionic bonds are stronger than covalent bonds because the electronegativity difference between the two elements is much greater than that of two elements in a covalent bond. In a covalent bond electrons are shared between the two elements and will often favor one element over the other depending on p...
- Mon Oct 26, 2020 1:31 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Chromium and Copper
- Replies: 5
- Views: 316
Re: Chromium and Copper
The same is true for period 5 as it shows the same trend. for example, the electron configuration of silver is [Kr] 4d¹⁰ 5s¹ and the configuration for molybdenum is [Kr] 4d₅ 5s₁.
- Mon Oct 26, 2020 1:29 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Hund's Rule
- Replies: 4
- Views: 224
Re: Hund's Rule
Hund's rule tells us about how the electrons in an atom should be placed into degenerate orbitals and is important for distinguishing characteristics of bonding because of how the electrons are placed.
- Fri Oct 23, 2020 10:35 pm
- Forum: DeBroglie Equation
- Topic: DeBroglie derivation
- Replies: 2
- Views: 161
DeBroglie derivation
Could someone please explain the conceptual significance of the derivation of the DeBroglie particle equation?
- Fri Oct 23, 2020 10:30 pm
- Forum: Empirical & Molecular Formulas
- Topic: workshop question emp formula
- Replies: 3
- Views: 247
Re: workshop question emp formula
The general process I use to find empirical formulas from combustion is as follows: 1. Balance the combustion reaction, 2. Convert CO2 and H2O to moles. 3. convert moles of co2 and h20 into moles of c and h, respectively, and convert into grams of each element. 3. Subtract sum of grams of C and H fr...
- Wed Oct 21, 2020 3:23 pm
- Forum: Ionic & Covalent Bonds
- Topic: 2A23 Part E
- Replies: 4
- Views: 607
Re: 2A23 Part E
The group 5 elements have five valence electrons in their highest-energy orbitals so they can form ionic compounds by gaining three electrons, forming anions, but I believe they more frequently form compounds through covalent bonding. Bismuth can lose either their outermost p electrons to form 3+ ch...
- Wed Oct 21, 2020 3:20 pm
- Forum: Photoelectric Effect
- Topic: Absorption of a photon
- Replies: 4
- Views: 104
Re: Absorption of a photon
Once the frequency of the light exceeds the threshold frequency, photoemission begins. I did some more research regarding this and found Plank's quantum hypothesis, which states that the vibrational energy of atoms in a solid is not continuous but has only discrete values, which I believe would mean...
- Mon Oct 19, 2020 3:45 pm
- Forum: *Shrodinger Equation
- Topic: Schrodinger for exam
- Replies: 20
- Views: 917
Re: Schrodinger for exam
Schrodinger's equation is important because wavefunctions of certain electrons are obtained as solutions to this equation. For example, atomic orbitals would be one.
- Fri Oct 16, 2020 8:46 pm
- Forum: Photoelectric Effect
- Topic: Sapling #4 Homework Part 2
- Replies: 9
- Views: 556
Re: Sapling #4 Homework Part 2
The second part of the question is basically asking how many electrons will be ejected when the energy of each photon is equal to the work function. This occurs when the kinetic energy of the electrons is zero. You would divide the given 7.21 x 10^-7 J by the found work function to find the number o...
- Thu Oct 15, 2020 11:41 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Difference regarding atomic spectroscopy and molecular spectroscopy
- Replies: 3
- Views: 340
Difference regarding atomic spectroscopy and molecular spectroscopy
I saw on the chemistry outline for the Quantum World there was one point that states: With respect to electron transitions that give rise to a UV or visible spectrum: understand the difference between electronic transitions in atomic orbitals (atomic spectroscopy) and electronic transitions in molec...
- Wed Oct 14, 2020 3:35 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: E 29 part c
- Replies: 15
- Views: 3324
Re: E 29 part c
Hi, we did this problem in discussion today but I missed the answers. For part a) I ended up getting 0.0423 moles and I was wondering why I got a different answer than posted above? I multiplied 8.61 g * (1 mol/ 202.484 g/mol). I got 202.484 g/mol by adding up the molar mass. I think it has to do w...
- Wed Oct 14, 2020 3:27 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Difference Between Absorption and Emission Spectroscopy
- Replies: 3
- Views: 371
Re: Difference Between Absorption and Emission Spectroscopy
So I was curious regarding this concept after the module as well and after doing some research I found that atomic emission spectroscopy uses transfer and differences in transfers of wavelengths to see how much was absorbed. It does go off of the fact that the wavelengths that are mitted are recorde...
- Mon Oct 12, 2020 11:53 am
- Forum: Properties of Electrons
- Topic: Experiments of electrons
- Replies: 5
- Views: 419
Re: Experiments of electrons
An easy way to remember that electrons behave as particles in the photoelectric experiment is to remember that when intensity of light was increased, it did not help to remove any more electrons from the metal. Here, increasing intensity of light increased the wavelength which had no effect on the e...