Search found 49 matches

by Veronica Rasmusen 2B
Wed Mar 14, 2018 7:58 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 887359

Re: Post All Chemistry Jokes Here

What is the name of the molecule CH2O?
Seawater
by Veronica Rasmusen 2B
Wed Mar 14, 2018 7:57 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 887359

Re: Post All Chemistry Jokes Here

What do chemists call a benzene ring with iron atoms replacing the carbon atoms?
A ferrous wheel
by Veronica Rasmusen 2B
Sat Mar 10, 2018 6:09 pm
Forum: Zero Order Reactions
Topic: graph of 0 order
Replies: 10
Views: 438

Re: graph of 0 order

For differential rate law, you would graph rate vs. concentration, and since rate only depends on k and not concentration, it would be a horizontal line that drops straight down when the reactants are consumed. For integrated rate law, you graph concentration vs. time for zero order reactions, the y...
by Veronica Rasmusen 2B
Sat Mar 10, 2018 6:05 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 887359

Re: Post All Chemistry Jokes Here

Why do white bears dissolve in water?
Because they're polar.
by Veronica Rasmusen 2B
Sat Mar 10, 2018 5:59 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 887359

Re: Post All Chemistry Jokes Here

A small furry animal walks into a bar and orders a drink.
The bartender says, "Sorry, our maximum occupancy is 6.02 x 10^23. We can't a serve a mole."
by Veronica Rasmusen 2B
Sat Mar 10, 2018 5:55 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 887359

Re: Post All Chemistry Jokes Here

How many moles are in guacamole?
Avocado's number
by Veronica Rasmusen 2B
Sat Mar 10, 2018 5:48 pm
Forum: Second Order Reactions
Topic: Differential vs Integrated
Replies: 4
Views: 328

Re: Differential vs Integrated

You would use differential rate law if you need to find the rate given certain concentrations.
Integrated rate law is used for finding concentrations given a certain time, or finding a final concentration from an initial concentration.
by Veronica Rasmusen 2B
Sat Mar 10, 2018 5:39 pm
Forum: First Order Reactions
Topic: Log vs ln
Replies: 9
Views: 436

Re: Log vs ln

There aren't really any cases log will be more convenient than ln, so just stick with natural log as it will always be more simple.
by Veronica Rasmusen 2B
Sat Mar 10, 2018 5:37 pm
Forum: General Rate Laws
Topic: Stoichiometric coefficients and order
Replies: 5
Views: 228

Re: Stoichiometric coefficients and order

For the most part, you should not use the balanced reaction and stoichiometric coefficients to find the order of a reaction. The order of the reaction will most likely be given in a question, or you will be given experimental data or a graph which you can use as well.
by Veronica Rasmusen 2B
Tue Feb 27, 2018 3:00 pm
Forum: Zero Order Reactions
Topic: zero order slopes
Replies: 5
Views: 204

Re: zero order slopes

If you are graphing rate vs. time the slope will be zero, however if you are graphing [A] vs. time there will be a slope = -k
by Veronica Rasmusen 2B
Tue Feb 27, 2018 2:50 pm
Forum: General Rate Laws
Topic: Negative Sign [ENDORSED]
Replies: 7
Views: 268

Re: Negative Sign [ENDORSED]

We always want positive rates. Since [R] is decreasing it will be negative, and a negative sign will need to be added to counteract that.
by Veronica Rasmusen 2B
Mon Feb 26, 2018 10:37 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Q and K
Replies: 7
Views: 261

Re: Q and K

Q and K are usually associated with equilibrium therefore the concepts regarding K>1 (products are favored) or Q>K (reactants are favored) or Q<K (products favored) are also constant
by Veronica Rasmusen 2B
Mon Feb 26, 2018 10:34 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: When do you need to include Pt? [ENDORSED]
Replies: 5
Views: 179

Re: When do you need to include Pt? [ENDORSED]

If there is no solid metal to act as a conductor, you use platinum
by Veronica Rasmusen 2B
Mon Feb 26, 2018 10:32 pm
Forum: Balancing Redox Reactions
Topic: Balancing number of electrons
Replies: 10
Views: 342

Re: Balancing number of electrons

It would make most sense the multiply by the least common multiple so you won't have to do additional simplification at the end, however theoretically you could multiply by any multiple as long as the electrons cancel out
by Veronica Rasmusen 2B
Mon Feb 26, 2018 10:31 pm
Forum: Balancing Redox Reactions
Topic: Gibbs free energy of half reactions
Replies: 4
Views: 187

Re: Gibbs free energy of half reactions

Since Gibbs free energy is a state function it can be added
by Veronica Rasmusen 2B
Mon Feb 26, 2018 10:30 pm
Forum: Balancing Redox Reactions
Topic: Recognizing a redox reaction in acidic or basic solution
Replies: 5
Views: 170

Re: Recognizing a redox reaction in acidic or basic solution

Whether the reaction occurs in acidic or basic conditions will most likely be given
by Veronica Rasmusen 2B
Mon Feb 26, 2018 10:27 pm
Forum: Balancing Redox Reactions
Topic: Half Reaction Order
Replies: 9
Views: 254

Re: Half Reaction Order

An oxidation reaction would have the electrons added on the right side of the arrow (electrons are lost) and a reduction reaction would have electrons on the left side (electrons are gained)
by Veronica Rasmusen 2B
Tue Feb 13, 2018 11:28 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Endothermic Favorable?
Replies: 2
Views: 210

Re: Endothermic Favorable?

Look at the equation delta G = delta H - T(delta S) If a reaction is endothermic then delta H will be positive. It depends whether delta S is negative or positive, and whether T is a high or low value to determine whether delta G will be negative (which would mean the reaction is favorable). If Delt...
by Veronica Rasmusen 2B
Tue Feb 13, 2018 11:21 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Gibbs free energy
Replies: 3
Views: 108

Re: Gibbs free energy

delta Go is delta G at standard conditions and delta G without the o is just the change in Gibb's free energy under any conditions
by Veronica Rasmusen 2B
Tue Feb 13, 2018 8:58 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Can deltaS = nR(ln(T2/T1)) be used to find change in entropy with varying temperature?
Replies: 1
Views: 122

Can deltaS = nR(ln(T2/T1)) be used to find change in entropy with varying temperature?

What equation should you use for when solving for the change in entropy with changing temperature? I thought the correct equation is deltaS = nC(ln(T2/T1)), however in the solutions manual the equation deltaS = nR(ln(T2/T1)) is used for question 9.13 Are these two equations interchangeable or should...
by Veronica Rasmusen 2B
Mon Feb 05, 2018 4:13 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Favorability
Replies: 4
Views: 166

Re: Favorability

Anytime deltaG is negative the reaction will be spontaneous and therefore favorable. If deltaS is positive the reaction is also usually favorable, unless deltaH is greater than deltaS times T (which can occur at low temperatures).
by Veronica Rasmusen 2B
Mon Feb 05, 2018 4:09 pm
Forum: Van't Hoff Equation
Topic: Equation
Replies: 4
Views: 248

Re: Equation

He just wanted to make sure that we knew that the equation we most commonly use is not the actual Van't Hoff equation but a version of it more applicable to questions that we would be asked.
by Veronica Rasmusen 2B
Mon Feb 05, 2018 4:06 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: The sign of the change in Gibb's Free Energy
Replies: 6
Views: 187

Re: The sign of the change in Gibb's Free Energy

When deltaG is negative it means the reaction is spontaneous, so it occurs easily and without work
by Veronica Rasmusen 2B
Mon Feb 05, 2018 3:56 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Closed vs. Isolated
Replies: 8
Views: 314

Re: Closed vs. Isolated

A closed system can exchange energy but not matter, and an isolated system can exchange neither.
by Veronica Rasmusen 2B
Mon Jan 22, 2018 11:41 pm
Forum: Phase Changes & Related Calculations
Topic: Accounting for mass in phase changes
Replies: 2
Views: 158

Re: Accounting for mass in phase changes

It depends what units your constants are in. If the heat capacity given uses moles, then you would have to convert grams to moles so the units cancel. If given specific heat capacity using grams you would not need to convert grams to moles.
by Veronica Rasmusen 2B
Mon Jan 22, 2018 11:35 pm
Forum: Phase Changes & Related Calculations
Topic: Irreversible and Reversible
Replies: 7
Views: 236

Re: Irreversible and Reversible

It would be a good idea to know the difference between irreversible and reversible reactions, but if it shows up on the test it will only be a conceptual question.
by Veronica Rasmusen 2B
Mon Jan 22, 2018 11:33 pm
Forum: Phase Changes & Related Calculations
Topic: Question on Cv(vap)
Replies: 2
Views: 106

Re: Question on Cv(vap)

Cv(vap) is 2.01 (J/C*g) for H2O, it is not something you calculate but will be given, or you can look it up.
by Veronica Rasmusen 2B
Mon Jan 22, 2018 11:31 pm
Forum: Phase Changes & Related Calculations
Topic: Heat capacities
Replies: 5
Views: 178

Re: Heat capacities

In this case, J/g*C is the same as J/g*K
by Veronica Rasmusen 2B
Mon Jan 22, 2018 11:29 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.45- why do you multiply?
Replies: 5
Views: 163

Re: 8.45- why do you multiply?

The delta H of 358.8 tells us the heat absorbed per mole of every substance in the reaction, this would mean there is 358.8 Kj/4 mol CS2, 358.8 KJ/4 mol C, and 358.8 KJ/ 1 mol S8. Therefore to find the heat absorbed by 1.25 mol of S8 we would multiply (358.8 KJ/ 1 mol S8) times (1.25 mol S8)
by Veronica Rasmusen 2B
Mon Jan 22, 2018 11:24 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Exothermic Reactions
Replies: 2
Views: 77

Re: Exothermic Reactions

Since the reactor will gain heat from the heat released by the reaction it will need to be cooled down
by Veronica Rasmusen 2B
Mon Jan 22, 2018 11:22 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hesss Law
Replies: 6
Views: 215

Re: Hesss Law

yes, as it is in our lecture notes and in our homework
by Veronica Rasmusen 2B
Mon Jan 22, 2018 11:16 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Different Delta H. Question 8.57
Replies: 2
Views: 134

Re: Different Delta H. Question 8.57

The C stands for combustion, so delta H with subscript C means the enthalpy change of combustion
by Veronica Rasmusen 2B
Sun Dec 03, 2017 9:33 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Sigma and Pi bonds
Replies: 2
Views: 154

Re: Sigma and Pi bonds

Pi bonds are formed by leftover p orbitals, so for example if an atom of carbon was double bonded to another atom of carbon (with each carbon single-bonded to another atom), the sigma bond would be sp3 hybridized and the pi bond would be 2p hybridized.
by Veronica Rasmusen 2B
Sun Dec 03, 2017 9:29 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Monodentate vs Bidentate etc. [ENDORSED]
Replies: 7
Views: 1113

Re: Monodentate vs Bidentate etc. [ENDORSED]

Monodentate refers to a ligand that bonds to the central transition metal at one point. A bidentate is a ligand that can bond at two points to the transition metal. So basically you would look for how many atoms in the ligand are electron donors and could make bonds to the central TM.
by Veronica Rasmusen 2B
Sun Nov 26, 2017 7:37 pm
Forum: Sigma & Pi Bonds
Topic: drawing sigma/pi bonds
Replies: 6
Views: 323

Re: drawing sigma/pi bonds

All single bonds would be labeled as sigma bonds, double bonds would have one sigma bond and one pi bond, and triple bonds would have one sigma bond and two pi bonds.
by Veronica Rasmusen 2B
Sun Nov 26, 2017 7:25 pm
Forum: SI Units, Unit Conversions
Topic: Significant Figures in relation to molar mass [ENDORSED]
Replies: 4
Views: 3209

Re: Significant Figures in relation to molar mass [ENDORSED]

For molar mass try to use as many decimal places as possible to be the most accurate. The number of sig figs in your final answer will still be the same as the initial amount of sig figs in the mass given (or whatever value given that has the least amount of sig figs)
by Veronica Rasmusen 2B
Sun Nov 19, 2017 11:39 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Chelates
Replies: 3
Views: 175

Re: Chelates

A chelate is a complex containing a ligand that forms a ring of atoms that includes the central metal ion. Chelating ligands can bind cations tightly, so they can be used to remove metals from solutions.
by Veronica Rasmusen 2B
Sun Nov 19, 2017 11:36 pm
Forum: Biological Examples
Topic: Cobalt
Replies: 4
Views: 281

Re: Cobalt

It's biological significance is that it is found in vitamin B12.
by Veronica Rasmusen 2B
Sun Nov 12, 2017 10:52 pm
Forum: Lewis Structures
Topic: Radicals
Replies: 7
Views: 290

Re: Radicals

Sophia Bozone 3 3B wrote:
Veronica Rasmusen 1E wrote:Most often, yes. With an odd number of electrons, there will be one electron ending up without a pair.

Thank you of this illuminating knowledge benevolent sir :-*


Why welcome fair kind maiden, hath 14a been treating thee kindly?
by Veronica Rasmusen 2B
Sun Nov 12, 2017 10:49 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Formal charge and lewis structures
Replies: 5
Views: 217

Re: Formal charge and lewis structures

It depends on what the question is asking, if the questions wants the most stable structure or the one with the least formal charge then yes you will have to calculate the formal charges on each atom and find the most correct structure. For more basic molecules this will often by the first one you d...
by Veronica Rasmusen 2B
Sun Nov 12, 2017 10:35 pm
Forum: Lewis Structures
Topic: Radicals
Replies: 7
Views: 290

Re: Radicals

Most often, yes. With an odd number of electrons, there will be one electron ending up without a pair.
by Veronica Rasmusen 2B
Sun Nov 12, 2017 10:30 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Lewis Structures and Formal Charge
Replies: 7
Views: 631

Re: Lewis Structures and Formal Charge

There are many cases where you will draw the most stable lewis structure right off the bat, but it's always a good idea to check formal charge in case just so you don't end up losing points.
by Veronica Rasmusen 2B
Sun Nov 12, 2017 10:26 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Drawing lewis structures
Replies: 5
Views: 251

Re: Drawing lewis structures

In most cases the best lewis structure will be the one with a central atom of the lowest ionization energy and formal charges of zero on each atom.
by Veronica Rasmusen 2B
Sun Nov 05, 2017 9:13 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 887359

Re: Post All Chemistry Jokes Here

Two scientists walk into a bar The first one says “I’ll have some H2O.” The second one says, “I’ll have some H2O too.” Then he dies.
by Veronica Rasmusen 2B
Sun Nov 05, 2017 9:12 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 887359

Re: Post All Chemistry Jokes Here

Did you hear about the guy who's temperature got down to absolute zero?
Don't worry, he's 0k.
by Veronica Rasmusen 2B
Sun Oct 29, 2017 10:38 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 887359

Re: Post All Chemistry Jokes Here

I don't trust atoms... they make up everything
by Veronica Rasmusen 2B
Sun Oct 29, 2017 10:38 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 887359

Re: Post All Chemistry Jokes Here

I try to tell chemistry jokes,
but there is no reaction :(
by Veronica Rasmusen 2B
Sun Oct 15, 2017 6:31 pm
Forum: Properties of Light
Topic: Homework 1.3
Replies: 2
Views: 160

Homework 1.3

Can someone explain why the extent of the change in the electrical field at a given point decreases when the frequency of electromagnetic radiation decreases?
by Veronica Rasmusen 2B
Sat Oct 14, 2017 5:46 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Confused about hw question 1.15 [ENDORSED]
Replies: 1
Views: 149

Confused about hw question 1.15 [ENDORSED]

Question: In the ultraviolet spectrum of atomic hydrogen, a line is observed at 102.6 nm. Determine the values of n for the initial and final energy levels of the electron during the emission of energy that leads to this spectral line. I was able to find the frequency (v) using the wavelength but I'...

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