Search found 27 matches

by Laila Sathe 1D
Thu Mar 10, 2016 9:36 pm
Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
Topic: Naming with cis/trans
Replies: 1
Views: 333

Re: Naming with cis/trans

No, when naming a cyclic molecule you only use cis/trans or E/Z when there are 2 substituents.
by Laila Sathe 1D
Sat Mar 05, 2016 10:14 pm
Forum: *Alkynes
Topic: Alkene and Alkyne
Replies: 2
Views: 750

Re: Alkene and Alkyne

What happens if the numbering would be equivalent either way?
by Laila Sathe 1D
Sun Feb 28, 2016 1:05 pm
Forum: *Alkanes
Topic: "Ethoxy" substituent
Replies: 1
Views: 317

"Ethoxy" substituent

In the examples in the course reader, there's one on page 96 that has the substituent "ethoxy" on a parent chain. How do you know to name the substituent this?
by Laila Sathe 1D
Mon Feb 22, 2016 10:18 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Sig figs
Replies: 2
Views: 407

Re: Sig figs

do you know what lavelle's policy is with temperature sig figs? a ta mentioned that we should ignore sig figs in temperature.
by Laila Sathe 1D
Mon Feb 22, 2016 10:13 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7951
Views: 1120037

Re: Chemistry Jokes

Einstein, Pascal, and Newton are playing hide and seek. Einstein is counting while Newton and Pascal hide. Pascal runs off and hides while Newton doesn’t move an inch. Instead, he draws a square around himself in the dirt. After Einstein finishes counting, he opens his eyes and says, “Found you Newt...
by Laila Sathe 1D
Sat Feb 13, 2016 2:40 pm
Forum: General Rate Laws
Topic: concentration of first-order integrated rate law
Replies: 1
Views: 449

Re: concentration of first-order integrated rate law

Look at the units of the constants given (initial concentration and k) and the units that should be in your answer.


You should multiply 3 quantities to get your answer.
by Laila Sathe 1D
Fri Feb 05, 2016 12:41 pm
Forum: Balancing Redox Reactions
Topic: Question 14.11 (d)
Replies: 3
Views: 568

Re: Question 14.11 (d)

How do you know what reaction takes place between the O2 and H+? I understand that they react because they are on the same side of the double line in the cell diagram, but I don't get how you figure out what reaction takes place.
by Laila Sathe 1D
Wed Feb 03, 2016 10:31 am
Forum: Balancing Redox Reactions
Topic: Balancing Basic Redox Reactions (HW 14.5 A)
Replies: 2
Views: 415

Re: Balancing Basic Redox Reactions (HW 14.5 A)

How do you know oxygen is being reduced? It goes from a neutral triatomic molecule to a neutral diatomic molecule. Does the oxidation state change in the reaction of O3-->O2?
by Laila Sathe 1D
Mon Feb 01, 2016 11:04 am
Forum: Balancing Redox Reactions
Topic: Basic or acidic solution?
Replies: 5
Views: 582

Re: Basic or acid solution?

I think the question will indicate that.
by Laila Sathe 1D
Sat Jan 23, 2016 6:47 pm
Forum: Calculating Work of Expansion
Topic: Work of Expansion
Replies: 1
Views: 328

Re: Work of Expansion

Work is negative relative to the system when the system expands because the system loses energy as it does work on the surroundings. It's positive when the system is compressed because the surroundings do work on the system. Because, in this case, delta V is negative, the value for work will be posi...
by Laila Sathe 1D
Fri Jan 15, 2016 11:11 am
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reversible Systems
Replies: 1
Views: 365

Re: Reversible Systems

Yes, there is. In fact, the work done by the system on the surroundings is maximized in a reversible system.
by Laila Sathe 1D
Thu Jan 07, 2016 11:37 am
Forum: Phase Changes & Related Calculations
Topic: Temperature Changes during Phase Changes
Replies: 1
Views: 369

Re: Temperature Changes during Phase Changes

Temp does not increase because the energy being added to the system is being used to break bonds and change the phase of matter instead of increasing the temperature. During the period of ice melting/freezing at 0 o C, the substance is actually a combination of water and ice, and energy is being add...
by Laila Sathe 1D
Fri Dec 04, 2015 2:56 pm
Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
Topic: Solving Buffers
Replies: 1
Views: 594

Re: Solving Buffers

When you add a strong base, like NaOH, to a solution it will dissociate fully, meaning it will completely ionize into Na + and OH - ions. Thus, the H + ions from the dissociation of the weak acid (HA) will bond with the hydroxide ions to form water. More because A - and H + are both on the same side...
by Laila Sathe 1D
Fri Dec 04, 2015 2:51 pm
Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
Topic: Buffer Region on a pH Curve
Replies: 2
Views: 596

Re: Buffer Region on a pH Curve

The buffer region ends when the pH starts to change significantly.
by Laila Sathe 1D
Tue Dec 01, 2015 3:42 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Q vs. K
Replies: 3
Views: 555

Re: Q vs. K

Q and K represent the same kind of value, but they're used at different times. K is the equilibrium constant, meaning it represents the ratio of products to reactants at equilibrium . Q is the reaction quotient, meaning it represents the ratio of products to reactants at some other point , not neces...
by Laila Sathe 1D
Thu Nov 26, 2015 11:03 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ICE Chart Original Value Change
Replies: 3
Views: 588

Re: ICE Chart Original Value Change

You can do it when it isn't obvious which direction the reaction will go. You push the reaction all the way to one side so you know what will be produced and consumed. You could also calculate Q to figure that out.
by Laila Sathe 1D
Fri Nov 20, 2015 12:13 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Endo vs. Exothermic
Replies: 6
Views: 3406

Re: Endo vs. Exothermic

I think there is, but for the purposes of this class we don't have to know that.
by Laila Sathe 1D
Sun Nov 15, 2015 4:18 pm
Forum: Naming
Topic: pentaaquachloroiron(III)
Replies: 1
Views: 506

Re: pentaaquachloroiron(III)

It's an ion, which means its charged. If it was Cl3, it would be trichloro instead of chloro
by Laila Sathe 1D
Fri Nov 13, 2015 12:18 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Conditions favoring production - pressure
Replies: 6
Views: 767

Re: Conditions favoring production - pressure

Actually, adding inert gasses has no effect on the equilibrium. As Dr. Lavelle mentioned, changing pressure changes concentrations and concentrations are then what affects the equilibrium position. When you add an inert gas, there is NO change to the concentrations of reactants (total volume and mol...
by Laila Sathe 1D
Fri Nov 06, 2015 12:09 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Relationship between Kc and Kp?
Replies: 2
Views: 609

Re: Relationship between Kc and Kp?

There is a formula... I would imagine Dr. Lavelle will teach it but he hasn't yet. It's derived from the Ideal Gas Law: K p =K c (RT) delta n This website may help: http://chemwiki.ucdavis.edu/Physical_Chemistry/Equilibria/Chemical_Equilibria/The_Equilibrium_Constant/Calculating_An_Equilibrium_Conce...
by Laila Sathe 1D
Wed Oct 28, 2015 9:09 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Trigonal Bipyramid Bond Angles
Replies: 1
Views: 540

Re: Trigonal Bipyramid Bond Angles

Think of just one pyramid with a square bottom. The atoms on each corner of the bottom of that pyramid will be 120 o away from one another. The atom at the top point of that pyramid will be 90 o away from the other atoms because it's in an orthogonal plane. When you add another atom on the opposite ...
by Laila Sathe 1D
Fri Oct 23, 2015 4:39 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Square Planar Angles
Replies: 4
Views: 1102

Re: Square Planar Angles

You're right, in a square pyramidal structure the bond angles are slightly less than 90 degrees according to VSEPR theory. And yes we do have to know about molecules in that form, which have the shorthand abbreviation AX5E.
by Laila Sathe 1D
Wed Oct 14, 2015 10:34 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration for Tungsten (W)
Replies: 1
Views: 1727

Re: Electron Configuration for Tungsten (W)

I was wondering this too and I found this: http://www.madsci.org/posts/archives/20"onclick="window.open(this.href);return false; ... .Ch.r.html Basically it's an exception to the exception. But Dr. Lavelle said we don't have to know any exceptions other than chromium and copper, so don't worry about...
by Laila Sathe 1D
Wed Oct 14, 2015 10:28 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration for Copper
Replies: 2
Views: 11331

Re: Electron Configuration for Copper

It's because copper is one of the exceptions to regular orbital filling rules: copper's electrons completely fill the 3d orbital and leave the 4s orbital with only one electron. Because the 4s orbital is a lower energy orbital than the 3d orbitals, the valence electron that is lost when Cu ionizes t...
by Laila Sathe 1D
Thu Oct 08, 2015 12:12 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Hunds Rule
Replies: 2
Views: 322

Re: Hunds Rule

Hund's rule basically says that due to the repulsive forces between electrons, electrons fill orbitals within a subshell in a specific way: they fill first all available orbitals in that subshell with just one electron, each with parallel spins. Then, only once each available orbital has one electro...
by Laila Sathe 1D
Thu Oct 08, 2015 12:07 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Degeneracy and Energy Levels
Replies: 2
Views: 393

Re: Degeneracy and Energy Levels

Yes, this has to deal with the concept of shielding. Electrons closer to the nucleus of the atom "shield" those that are farther away; the inner electrons' e-e repulsions with those that are farther away decrease the attractive force between the nucleus and those farther electrons.
by Laila Sathe 1D
Thu Oct 01, 2015 3:23 pm
Forum: Empirical & Molecular Formulas
Topic: Find purity using percentage composition and yield
Replies: 2
Views: 412

Re: Find purity using percentage composition and yield

How do you calculate the theoretical and percent yield in this problem?

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