## Search found 83 matches

Sat Mar 16, 2019 8:30 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Week 10 Discussion Notes (2E,2I,2K)
Replies: 6
Views: 10553

### Re: Week 10 Discussion Notes (2E,2I,2K)

Meachelle_Lum_1I wrote:Hi, does anyone know why delta H was 300 and not -300 when calculating the reverse activation energy? Didn't they give it as -300, and it's an exothermic reaction so deltaH should be negative?

Going in reverse, you'd switch the sign around. You're doing the reaction backwards.
Sat Mar 16, 2019 7:59 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Week 10 Discussion Notes (2E,2I,2K)
Replies: 6
Views: 10553

### Re: Week 10 Discussion Notes (2E,2I,2K)

Thank You!
Sat Mar 16, 2019 7:51 pm
Forum: *Enzyme Kinetics
Topic: true statement?
Replies: 4
Views: 368

### Re: true statement?

Yes. When you look at the Arrhenius equation we can see that increasing temperature makes the rate larger, as does lowering the activation energy, which is what a catalyst does, so doing these together should theoretically increase the enhancement of the rate. But isn't the statement saying that th...
Wed Mar 13, 2019 10:19 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Isothermal
Replies: 5
Views: 202

### Re: Isothermal

In isothermal dU=0, and we know that work is done so U=w, so what this means is that 0=q+w, q=-w/w=-q, while there's no temp change heat is released but counteracted by work. heat being measured in joules. If there was no heat across the system then it would be adiabatic system not isothermal.
Wed Mar 13, 2019 10:12 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Multistep entropy problems
Replies: 2
Views: 318

### Re: Multistep entropy problems

You can't assume that the pressure is constant, but you can assume that volume is constant. So youre able to calculate one change for that temp change and one change for the volume change. Since entropy is a state function, its independent of the path taken so you're able to calculate them separate...
Wed Mar 13, 2019 10:10 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Multistep entropy problems
Replies: 2
Views: 318

### Re: Multistep entropy problems

You can't assume that the pressure is constant, but you can assume that volume is constant. So youre able to calculate one change for that temp change and one change for the volume change.
Wed Mar 13, 2019 10:09 pm
Forum: *Enzyme Kinetics
Topic: true statement?
Replies: 4
Views: 368

### Re: true statement?

Yes. When you look at the Arrhenius equation we can see that increasing temperature makes the rate larger, as does lowering the activation energy, which is what a catalyst does, so doing these together should theoretically increase the enhancement of the rate.
Wed Mar 13, 2019 10:05 pm
Forum: General Rate Laws
Topic: determining the rate of reaction for individual components in the reaction
Replies: 1
Views: 71

### Re: determining the rate of reaction for individual components in the reaction

It'll be negative because in order to form products you have to lost matter from the reactants
Tue Mar 12, 2019 10:14 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Concentration cell textbook question 6N. 3A self test [ENDORSED]
Replies: 4
Views: 39875

### Re: Concentration cell textbook question 6N. 3A self test[ENDORSED]

jane_ni_2d wrote:so its correct that the anode is always on the left of the concentration cell right?

Yes.
Fri Mar 08, 2019 3:48 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: What is q equal to in the second law of thermodynamics?
Replies: 5
Views: 381

### Re: What is q equal to in the second law of thermodynamics?

BenJohnson1C wrote:T can be completely canceled out. Think of it as the -q=w. Because the function for work involves the multiplication of T but deltaS is q/T, the q is simply taken out and the negative sign is omitted.

Thanks Ben that helps!!!
Fri Mar 08, 2019 3:48 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: What is q equal to in the second law of thermodynamics?
Replies: 5
Views: 381

### Re: What is q equal to in the second law of thermodynamics?

Summer de Vera 2C wrote:
Lauren Huang 1H wrote:The second law of thermodynamics states that delta S=q/T=nRln(V2/V1). So q=nRTln(V2/V1) if you multiply both sides by temperature. I believe the unit for q is Joules.

Wouldn't you have to divide rather than multiply both sides by T?

I believe its divide;.
Fri Mar 08, 2019 3:46 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Unique Rates
Replies: 3
Views: 184

### Re: Unique Rates

If youre given the a small rate in a multi compound reaction then the one with the smallest rate has stoichiometric coefficient of 1 while the other rates will be relative to this value (x) divided by their own stoichiometric coefficients, which means all of these values will be equal to each other ...
Fri Mar 08, 2019 3:43 pm
Forum: Zero Order Reactions
Topic: Determining Rate Orders
Replies: 3
Views: 141

### Re: Determining Rate Orders

There's good examples of this in this weeks worksheets posted by a UA
Fri Mar 08, 2019 3:27 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Week 9 Worksheet (2E,I,K)
Replies: 13
Views: 4557

### Re: Week 9 Worksheet (2E,I,K)

Wed Mar 06, 2019 5:30 pm
Forum: First Order Reactions
Topic: How to do 15.11 6th edition?
Replies: 4
Views: 178

### Re: How to do 15.11 6th edition?

The problem tells you that N2O5 decomposes by a first order reaction, so the rate law will have the form rate = k[A] where A is the reactant, N2O5, and the it is raised to the first power since it is a first order reaction. You are also given k = 5.2 x 10^-3. As mentioned before, you don't need to ...
Wed Mar 06, 2019 4:38 pm
Forum: First Order Reactions
Topic: How to do 15.11 6th edition?
Replies: 4
Views: 178

### How to do 15.11 6th edition?

I cannot figure out how to solve this problem or how heat is even factored into it?
Thu Feb 28, 2019 4:53 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Problem 4A.9) 7th edition of the textbook [ENDORSED]
Replies: 7
Views: 36601

### Re: Problem 4A.9) 7th edition of the textbook[ENDORSED]

In this problem, the solutions manual says that heat lost by metal = - heat gained by water. Why would the heat gained by water be negative? Well thinking about it, if the metal loses heat its value will be negative and since that is negative, H(metal)=-H(water), H(metal)=-x, H(water)=-(-H(metal)= ...
Thu Feb 28, 2019 4:43 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagrams in 14.15 and 14.17 6th Ed
Replies: 4
Views: 189

### Re: Cell Diagrams in 14.15 and 14.17 6th Ed

When two aqueous solutions are in the same cell they're split with a comma while if they're other phases they're separated with a line. Right, but Ni(OH)3(s) and Ni(OH)2(s) are in the same phase still and is still separated by a line? Yeah, if theyre any other phase except aqueous they are split wi...
Thu Feb 28, 2019 4:41 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell potential
Replies: 2
Views: 102

### Re: Cell potential

As said above you get the cell potentials of the cathode and anode then do E(standard)=E(cathode)-E(anode).
Tue Feb 26, 2019 11:09 pm
Forum: Balancing Redox Reactions
Topic: Gibbs Free Energy
Replies: 2
Views: 148

### Re: Gibbs Free Energy

You'd use dG=-nFE. Where you need to find the electrons that flow between the two cells and that is your n while E is given and F is a constant, this gives you your gibbs free energy of the cell.
Tue Feb 26, 2019 11:07 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagrams in 14.15 and 14.17 6th Ed
Replies: 4
Views: 189

### Re: Cell Diagrams in 14.15 and 14.17 6th Ed

When two aqueous solutions are in the same cell they're split with a comma while if they're other phases they're separated with a line.
Tue Feb 26, 2019 11:06 pm
Forum: Balancing Redox Reactions
Topic: 6K.1 7th edition
Replies: 1
Views: 92

### Re: 6K.1 7th edition

In order to balance the waters, and hydrogens, and electrons of both half reactions you'll need to multiply by those coefficients.
Tue Feb 26, 2019 11:04 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Question for Test 2
Replies: 4
Views: 137

### Re: Question for Test 2

Yup everything up to the nernst equation
Sun Feb 24, 2019 11:04 pm
Forum: Balancing Redox Reactions
Topic: Mnemonic for Redox
Replies: 5
Views: 277

### Re: Mnemonic for Redox

I just try to remeber that when it says reducing it means reducing the oxidation number by making it more negative by gaining electrons which reduce the oxidation number while oxidating increases oxidation number.
Sun Feb 24, 2019 11:02 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Which equation to use
Replies: 2
Views: 110

### Re: Which equation to use

Youd use that when they are asking about equilibrium onstants, G=gstandard+RTln(q) when not at equilibrium, G=Gstan+RTln(p) when talking about pressure, and G=-RTln(k) when talking about equilibrium constant.
Sun Feb 24, 2019 11:00 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell diagram
Replies: 4
Views: 153

### Re: Cell diagram

Professor lavelle said the anode is always on the left and cathode on the right to represent electron flow.
Sun Feb 24, 2019 11:00 pm
Forum: Administrative Questions and Class Announcements
Replies: 179
Views: 12565

Thanks for the worksheet it helped a lot!
Sat Feb 09, 2019 7:11 pm
Forum: Phase Changes & Related Calculations
Topic: What exactly is 3/2RT and when do we use it?
Replies: 4
Views: 981

### Re: What exactly is 3/2RT and when do we use it?

Matthew Mar 1J wrote:I don't know if this is directly related, but 3/2R (without the T) is the specific heat capacity of a monatomic ideal gas at constant volume (Cv) which is used in entropy problems (/\S = n Cv ln(T1/T2)) which is a more practical application.

Then what about when it is constant pressure?
Fri Feb 08, 2019 3:35 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: If not Gibbs Free Energy then what is the last topic for midterm?
Replies: 4
Views: 134

### If not Gibbs Free Energy then what is the last topic for midterm?

The outline says through entropy but gibbs free energy is last and theres a few other things so what is it?
Wed Feb 06, 2019 3:34 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: What is q equal to in the second law of thermodynamics?
Replies: 5
Views: 381

### What is q equal to in the second law of thermodynamics?

As in how would it be presented in a problem and in what units?
Wed Feb 06, 2019 3:13 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Why does q=-w?
Replies: 1
Views: 100

### Why does q=-w?

Is this because the heat exploited is being contained by the same amount of work hence the dU=0 because they counteract each other?
Wed Feb 06, 2019 3:11 pm
Forum: Phase Changes & Related Calculations
Topic: What exactly is 3/2RT and when do we use it?
Replies: 4
Views: 981

### What exactly is 3/2RT and when do we use it?

Title
Wed Feb 06, 2019 12:09 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: 6th Edition Problem 8.21
Replies: 8
Views: 292

### Re: 6th Edition Problem 8.21

What would cp be in this equation?
Wed Feb 06, 2019 12:08 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: 6th Edition Problem 8.21
Replies: 8
Views: 292

### Re: 6th Edition Problem 8.21

What would cp be in this equation?
Thu Jan 31, 2019 1:28 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Homework
Replies: 9
Views: 317

### Re: Homework

Im extremely lost in this chapter as im using the sixth edition do you think finding a 7th edition would help?
Thu Jan 31, 2019 1:27 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: steam vs. water
Replies: 5
Views: 282

### Re: steam vs. water

Steam is hotter water, so hot it turned into a different phase state.
Thu Jan 31, 2019 1:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: What do do when moles are given
Replies: 5
Views: 197

### What do do when moles are given

when a problem says there is 3 moles or 6 moles of a certain molecule do we just use that value to find the concentration or do we put the moles given in the exponent of our equilibrium constant equation?
Thu Jan 24, 2019 11:26 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Neutral solutions
Replies: 2
Views: 101

### Re: Neutral solutions

The solution is neutral when K is between 10^-3 and 10^3 as the reaction does not significantly favor either sides reaction.
Thu Jan 24, 2019 11:21 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: When to ignore change in Acid
Replies: 5
Views: 205

### When to ignore change in Acid

Do you ignore the change in acid when its 1 x 10^-3 or less?
Thu Jan 17, 2019 11:31 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 6A.23
Replies: 2
Views: 111

### Re: 6A.23

This is problem 12.25 and when I added up the atomic number of BrOH2 and then divided the given grams by that I got 2.5x10^-2.
Thu Jan 17, 2019 11:26 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: pKa and pKb
Replies: 4
Views: 601

### Re: pKa and pKb

Remember that on the pH scale Acid is a lower number so when you have a low Pka that means its a strong acid.
Wed Jan 16, 2019 10:49 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Question 11.35 6th edition
Replies: 2
Views: 141

### Question 11.35 6th edition

If we are given pKa=2.12 would we find Ka by simply taking 10^2.12 = 131.825 or ? How do you find Ka from pKa?
Wed Jan 16, 2019 10:48 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Question 11.35 6th edition
Replies: 1
Views: 82

### Question 11.35 6th edition

If we are given pKa=2.12 would we find Ka by simply taking 10^2.12 = 131.825 or ? How do you find Ka from pKa?
Fri Jan 11, 2019 1:26 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Can you cause a shift in equilibrium by increasing pressure by adding in a non-gas?
Replies: 2
Views: 53

### Re: Can you cause a shift in equilibrium by increasing pressure by adding in a non-gas?

If you add a solid you decrease the amount of volume which would increase pressure it seems to me?
Fri Jan 11, 2019 1:19 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kp
Replies: 9
Views: 298

### Re: Kp

Kp simply related to the equilibrium constant when everything reacting is a gas but the process of finding it is the same as the Kc equation.
Fri Jan 11, 2019 1:17 pm
Forum: Equilibrium Constants & Calculating Concentrations
Replies: 2
Views: 67

If there is a reaction in which there is only gas in the reactants and they form solids do you then just put a one in the denominator of the kc equation.
Sat Dec 08, 2018 3:49 pm
Forum: Air Pollution & Acid Rain
Topic: Acid Rain and Respiratory Acidosis
Replies: 1
Views: 272

### Re: Acid Rain and Respiratory Acidosis

I'd say at least learn the whole chemical formula, and why it acts that way behind the formation of acid rain.
Tue Dec 04, 2018 6:18 pm
Forum: Bronsted Acids & Bases
Topic: Negative pH
Replies: 1
Views: 133

### Re: Negative pH

Yup if the mol/l is greater than one then the pH is negative.
Tue Dec 04, 2018 5:58 pm
Forum: Naming
Topic: Ligand Charge
Replies: 1
Views: 56

### Re: Ligand Charge

Well you can determine the charge of the ligand by drawing the lewis strucuture and finding formal charge and by doing this you will find NH3 is neutral so the metal ion must have a 3+ charge
Tue Dec 04, 2018 5:56 pm
Forum: Student Social/Study Group
Topic: Tuesday Review Session
Replies: 1
Views: 309

### Re: Tuesday Review Session

Following this same exact reason.
Tue Dec 04, 2018 5:55 pm
Forum: Amphoteric Compounds
Topic: Acidic, Basic, and Amphoteric Oxides
Replies: 2
Views: 156

### Re: Acidic, Basic, and Amphoteric Oxides

Usually if it is binding with a metal it is basic, and if its binding with a non metal its acidic but you usually need to find out experimentally but generally the first two groups are basic.
Tue Dec 04, 2018 5:46 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Significance of Equilibrium Constants
Replies: 2
Views: 139

### Re: Significance of Equilibrium Constants

If the acid has a higher a equilibrium constant that means it is a stronger acid which means its bond is stronger which makes sense that it would have a higher equilibrium constant because it would have the hardest bond to break.
Wed Nov 28, 2018 3:09 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Identifying intermolecular forces
Replies: 4
Views: 182

### Re: Identifying intermolecular forces

The more Electronegative the atom the stronger it's force is so a Fluoride is very strong(because of how many valence electrons it has, and how small its atomic radius is) and extremely electronegative when compared to say a regular carbon bond, it's charge isn't entirely negated by bonding so its s...
Wed Nov 28, 2018 2:49 pm
Forum: Hybridization
Topic: Biological Importance
Replies: 1
Views: 83

### Re: Biological Importance

Hybridization allows for certain Transition metal Cations to form a complex with an electron rich molecule, this can form coordination compounds which have many important biological significances such as how Iron forms a Heme complex by bonding with a Porphyrin Ligand, then when you bind a heme comp...
Wed Nov 28, 2018 12:55 pm
Forum: Hybridization
Topic: Sigma and Pi bonds and hybridization
Replies: 1
Views: 68

### Re: Sigma and Pi bonds and hybridization

Because if you're forming sigma bonds, youre doing so through a new hybridized spx orbital, but Pi bonds are formed by electrons that do not leave the p block so they are just simple p block electrons that make non rotating bonds with other P orbitals.
Wed Nov 28, 2018 12:51 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Correct Bond Angles
Replies: 6
Views: 251

### Re: Correct Bond Angles

There will always be a slight difference between different molecules, and their intramolecular processes which we probably won't cover, but lmk if anyone gives you a table with Lavelles exact wants because right now it seems like as long as you're close it's okay.
Wed Nov 28, 2018 12:49 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 7th edition 2E.25 a)
Replies: 1
Views: 76

### Re: 7th edition 2E.25 a)

However the structure is tetrahedral, the way that the atoms align in real life will have the hydrogens on the dorsal side and the chlorines on the ventral(or vice versa), and because the the very different electronegativities of H and CL they will create an effective polar molecule.
Wed Nov 28, 2018 12:44 pm
Forum: Hybridization
Topic: Imagining Hybridization
Replies: 2
Views: 129

### Re: Imagining Hybridization

Awesome, thank you.
Fri Nov 23, 2018 10:29 am
Forum: Hybridization
Topic: Imagining Hybridization
Replies: 2
Views: 129

### Imagining Hybridization

When we say that at atom has entered 2sp^3 (say carbon) what exactly has happened to the electrons that broke in the S orbital and joined the P orbital and what does a sp3 orbital now look like?
Fri Nov 23, 2018 10:24 am
Forum: Dipole Moments
Topic: Chemistry Community
Replies: 5
Views: 176

### Re: Chemistry Community

You get points for all interactions, and also I have heard that the limit is not simply 3 a week but if you continue to interact you will be given more points.
Fri Nov 23, 2018 10:21 am
Forum: Hybridization
Topic: reason for hybridization
Replies: 9
Views: 2179

### Re: reason for hybridization

It is an experimentally observed way that bonds are formed, for instance in carbon there is 4 bonds made however carbon has 2s^2 and 2p^2 so technically it only has 2 valence electrons in an incomplete shell, so what happens when carbon is entering it's bonding state the 2s electrons diffract and jo...
Fri Nov 23, 2018 10:12 am
Forum: Balancing Chemical Reactions
Topic: Why do we balance chemical equations?
Replies: 13
Views: 1000

### Re: Why do we balance chemical equations?

I put to conserve the law of conservation of mass and I got it right.
Wed Nov 14, 2018 5:19 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape
Replies: 4
Views: 189

### Re: Molecular Shape

The number of bonding atoms (bond type is irrelevant), and the number of lone electrons on the central atom. We can see this in the VSEPR formulas AXE. A= central atom, X= bonding pairs to central atom, E= number of lone electron pairs, each of these is denoted with subscripts telling the quantity o...
Wed Nov 14, 2018 5:18 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability v. Polarizing Power
Replies: 2
Views: 177

### Re: Polarizability v. Polarizing Power

Cation refers to elements that want to give electrons while anions refer to elements that want to receive electrons. Anions are highly polarizable because they are highly electronegative which means they want to receive an electron, and a cation is highly polarizing because it has a highly positive ...
Wed Nov 14, 2018 5:12 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Strengths
Replies: 5
Views: 225

### Re: Bond Strengths

Because Ionic bonds are complete giving of one electron to another due to a high electonegative difference, while hydrogen bonding is the slight positive and negative sides of a molecule allowing two molecules to interact. The former is a stronger interaction.
Thu Nov 08, 2018 12:04 pm
Forum: Formal Charge and Oxidation Numbers
Topic: How do both intersect?
Replies: 3
Views: 218

### Re: How do both intersect?

They are basically the same oxidation is the number of electrons needed to fill, or number needed to take away to fill an octet, and formal charge shows the overall charge of an atom and what it needs to balance that charge which is usually done by the formation of an octet.
Thu Nov 08, 2018 12:01 pm
Forum: Resonance Structures
Replies: 11
Views: 740

Any atom with an unpaired valence electrong for instance sc2+.
Thu Nov 08, 2018 12:00 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration for Ions
Replies: 2
Views: 281

### Re: Electron Configuration for Ions

Because potassium in this instance does not ever fill it's d shell because it doesnt have the atomic configuration to be in that orbital while for scandium it has the atomic configuration(protons+neutrons+electrons) that has it fill the 3d orbital which is of higher energy than the 4s in the ion, an...
Thu Nov 08, 2018 11:37 am
Forum: Bond Lengths & Energies
Topic: Special Bond Length Rules
Replies: 3
Views: 171

### Re: Special Bond Length Rules

Nope! Shorter bond length= stronger attractions, longer bond length=weaker attraction.
Thu Nov 08, 2018 11:36 am
Forum: Ionic & Covalent Bonds
Topic: Periodic Trends
Replies: 3
Views: 187

### Re: Periodic Trends

The above comment is wrong, Ca is actually more electronegative. Electronegativity increases as you go up a group and across a row because the farther up a group the less protons which means less pull to the nucleus and across the row means more valence electrons which increases the negative charge,...
Thu Nov 08, 2018 11:20 am
Forum: Lewis Structures
Topic: Formal charges
Replies: 15
Views: 486

### Re: Formal charges

I asked about this in class, you do not need to write the formal charge of each atom in its lewis structure, but if you're checking for resonance you'll need to calculate it and see if there are any alternate structures.
Thu Nov 08, 2018 11:18 am
Forum: Resonance Structures
Topic: Resonance Structures
Replies: 3
Views: 177

### Re: Resonance Structures

Check the formal charge of the lewis strucutre you drew, and then see if you can optimize it at all and come up with the same formal charge. If you can do this then there is resonance.
Thu Nov 08, 2018 11:15 am
Forum: Lewis Structures
Topic: Expanded octet
Replies: 4
Views: 206

### Re: Expanded octet

Because when molecules have access to the d orbital they are able to store more electrons.
Thu Nov 08, 2018 11:11 am
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge & Stable lewis structures
Replies: 6
Views: 335

### Re: Formal Charge & Stable lewis structures

Just try to limit the amount of charges, and the quantity of that charge as much as possible as that shows the most stable structure but yes the charges should add up from each atom to the overall formal charge. Also make sure that if you have to make a decision about where to put - or + charges the...
Fri Nov 02, 2018 2:46 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: f- orbital
Replies: 3
Views: 188

### Re: f- orbital

Observe the atom numbers of the elements in the f block,notice where they fit in with the rest of the table, everything with atomic numbers above 58 will have electrons in the f block.
Fri Nov 02, 2018 2:41 pm
Forum: Ionic & Covalent Bonds
Topic: 7th edition 2A.1 c
Replies: 1
Views: 45

### Re: 7th edition 2A.1 c

If you can figure out how to write the electron structure youll see Mn=[Ar]3d^54s^2. You see that there are 5 electrons in the last empty shell so it has 5.
Fri Nov 02, 2018 2:27 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Quantum Numbers related to Orbitals
Replies: 4
Views: 180

### Re: Quantum Numbers related to Orbitals

Pretty sure its completely arbitrary as long as the other electron in pair has the other sign.
Thu Oct 18, 2018 12:26 am
Forum: Trends in The Periodic Table
Topic: atomic orbitals
Replies: 2
Views: 107

### Re: atomic orbitals

Each shell consists of orbitals in which you can calculate the probability of finding electrons within certain parts of through mathematical processes like Schrodingers equation. You cannot determine the exact position or velocity of these electrons as they are so small and moving so fast we may onl...
Wed Oct 17, 2018 11:50 pm
Forum: SI Units, Unit Conversions
Topic: Significant Figures for Adding Numbers in Scientific Notation
Replies: 2
Views: 170

### Re: Significant Figures for Adding Numbers in Scientific Notation

Shouldn't it be three significant figures considering in the problem he has 1.11 which has 3 sig figs compared to 1.1 which only has two, despite the scientific notation of the 10^x?
Wed Oct 17, 2018 11:47 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Determining Orbitals
Replies: 1
Views: 132

### Re: Determining Orbitals

Each s,p,d,f all have their own specific numbers of orbitals they go like this s:1 p:3 d:5 and f:7 so the shells start at 1 and increase b two in every subsequent shell.
Sun Oct 07, 2018 2:18 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: E1
Replies: 3
Views: 95

### Re: E1

So the question is asking how long would 1.00 mol of Ag (6.022 x 10^23 atoms) strung together end to end would be. So, you know that the radius of each atom is 144pm, then the length of each atom would be double that, so now you have diameter 288, you then take 288pm(length of one atom in its entire...
Sun Oct 07, 2018 2:12 pm
Forum: Properties of Light
Topic: Topic 1A #3
Replies: 2
Views: 95

### Re: Topic 1A #3

I am unsure as to what book and problem you are referring to, I think the rules are that we need to post the full problem in context.
Sun Oct 07, 2018 12:17 pm
Forum: Limiting Reactant Calculations
Topic: Limiting Reactants M19
Replies: 4
Views: 203

### Re: Limiting Reactants M19

Well you would have to get the info that the composition of caffeeing is c(8)H(10)N(4)O(2), then you could construct a chemical equation and balance it, then using the known molecular mass, and the weight of the products we could use dimensional analysis and come up with the empirical, then molecula...