Search found 31 matches

by Renee Delamater 2H
Sat Mar 17, 2018 5:21 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7582
Views: 1015072

Re: Post All Chemistry Jokes Here

Why can't you trust atoms? They make everything up!!!!!!!
by Renee Delamater 2H
Sun Mar 11, 2018 11:28 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Catalysts
Replies: 3
Views: 139

Re: Catalysts

I would also like to know the answer to this question
by Renee Delamater 2H
Sun Mar 11, 2018 11:25 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: K and K'
Replies: 4
Views: 160

Re: K and K'

I don't think there is a way to numerically calculate k' from k without knowing the K because K is always involved in the equation K=k/k'
by Renee Delamater 2H
Sun Mar 11, 2018 11:22 pm
Forum: *Enzyme Kinetics
Topic: Enzyme
Replies: 5
Views: 475

Re: Enzyme

Enzymes are catalysts and their job is to lower the activation energy - the energy needed for the reaction to get between the products and reactants point.
by Renee Delamater 2H
Tue Mar 06, 2018 11:50 pm
Forum: Second Order Reactions
Topic: molecularity
Replies: 6
Views: 393

Re: molecularity

Even though there are only NO molecules in the problem, using 2 of the NOs makes it bimolecular.
by Renee Delamater 2H
Tue Mar 06, 2018 11:48 pm
Forum: *Enzyme Kinetics
Topic: Catalyst
Replies: 6
Views: 425

Re: Catalyst

I agree - usually the enzyme or catalyst is used in the rxn to change its rate. It wold go above the equation or be given in the word problem.
by Renee Delamater 2H
Tue Mar 06, 2018 11:47 pm
Forum: Second Order Reactions
Topic: Rate of consumption vs concentration
Replies: 2
Views: 202

Re: Rate of consumption vs concentration

why would it be a less dramatic decrease?
by Renee Delamater 2H
Wed Feb 28, 2018 9:21 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Hw 15.1 [ENDORSED]
Replies: 7
Views: 308

Re: Hw 15.1 [ENDORSED]

it would make sense here because there is only one mole of N2 and 3 moles of H2 - in order to make a full 1, you would need 3 times more N2 to balance our for the amount of H2
by Renee Delamater 2H
Wed Feb 28, 2018 9:15 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: units of K
Replies: 5
Views: 228

Re: units of K

Britney Alvey 1B wrote:For 0 order reactions, the units for k are are mol/(L*s). For 1st order reactions, the units of k are s^(-1). For 2nd order reactions, the units for k are L/(mol*s).
why are these the units? does it have to do with each graph for first order, zero order, and second order reactions?
by Renee Delamater 2H
Wed Feb 28, 2018 9:08 pm
Forum: First Order Reactions
Topic: Derivation
Replies: 8
Views: 313

Re: Derivation

My TA said that if he asks us to derive on the exam, then it would be simple equations that we have gone over many times.
by Renee Delamater 2H
Tue Feb 20, 2018 10:55 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Help on 14.15 half-reactions
Replies: 1
Views: 125

Re: Help on 14.15 half-reactions

I'm not sure about these either - also what is the difference between a solubility equilibrium, the Brønsted neutralization reaction, and the reaction in the nickel–cadmium cell??
by Renee Delamater 2H
Tue Feb 20, 2018 10:50 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: When to include electrolyte in cell diagram
Replies: 1
Views: 85

Re: When to include electrolyte in cell diagram

I would also be intersted in knowing the answer to this question - thanks!
by Renee Delamater 2H
Tue Feb 20, 2018 10:49 pm
Forum: Balancing Redox Reactions
Topic: Basic and Acidic conditions [ENDORSED]
Replies: 11
Views: 3376

Re: Basic and Acidic conditions [ENDORSED]

These statements are all right. OH is a negative charge, so you will use this with basic solutions while H3O is positive, so you will use this in acidic conditions. H2O is unlimited and you can always include this
by Renee Delamater 2H
Tue Feb 13, 2018 10:51 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Practice Midterm [ENDORSED]
Replies: 5
Views: 420

Re: Practice Midterm [ENDORSED]

For this week's discussion, do we still have to hand in homework because the midterm is this week? I'm assuming we do but just checking!
by Renee Delamater 2H
Tue Feb 13, 2018 10:50 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Derivation of Formulas
Replies: 5
Views: 340

Re: Derivation of Formulas

Last week, my TA said that we may need to know some but these would just be very simple equations we've gone over a lot of times during lecture.
by Renee Delamater 2H
Tue Feb 13, 2018 10:49 am
Forum: Phase Changes & Related Calculations
Topic: Practice Problem
Replies: 3
Views: 152

Re: Practice Problem

I would also like to know how to do this problem! Thanks!
by Renee Delamater 2H
Tue Feb 06, 2018 5:00 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Textbook 9.7
Replies: 2
Views: 133

Re: Textbook 9.7

For constant pressure, you use 5/2R in the equation and for constant volume, you use 3/2R.
by Renee Delamater 2H
Tue Feb 06, 2018 3:53 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: 9.11
Replies: 2
Views: 130

Re: 9.11

Thanks!!!! :)
by Renee Delamater 2H
Tue Feb 06, 2018 1:45 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: 9.11
Replies: 2
Views: 130

9.11

For chapter 9 question 11 it asks the entropy change with a change in pressure and given moles. What is the equation we use for this? Thanks!
by Renee Delamater 2H
Wed Jan 31, 2018 10:06 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: bond enthalpies
Replies: 3
Views: 172

Re: bond enthalpies

These values are always given - we do not need to memorize them.
by Renee Delamater 2H
Wed Jan 31, 2018 10:04 pm
Forum: Phase Changes & Related Calculations
Topic: Example in Lecture
Replies: 4
Views: 194

Re: Example in Lecture

The reason we put Delta G as 0 as well is because we didn't have that or T as givens for the equation: DeltaG= DeltaH-TDeltaS. We had H and S, but needed something for G in order to find T - when the reaction would be spontaneous. Putting it at 0 is a good first step and makes sense here because we ...
by Renee Delamater 2H
Wed Jan 31, 2018 9:57 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat Capacity
Replies: 8
Views: 457

Re: Heat Capacity

Why do liquids have a higher heat capacity?
by Renee Delamater 2H
Tue Jan 23, 2018 10:25 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.49
Replies: 1
Views: 121

8.49

How do you find the change in internal energy with only a reaction and delta H given? It says "What is the change in internal energy for the reaction of 1.00 mol OF2? in the reaction OF2(g) + H2O(g) = O2(g) + 2H(g)." How do you find this for only 1 mole of one of the reactants?
by Renee Delamater 2H
Tue Jan 23, 2018 10:17 pm
Forum: Administrative Questions and Class Announcements
Topic: Week 3 Test Topic is endorsed
Replies: 37
Views: 1908

Re: Week 3 Test Topic is endorsed

Content from this week won't be on the exam, right? I'm pretty sure it's just material from Weeks 1 and 2
by Renee Delamater 2H
Wed Jan 17, 2018 9:34 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hess's Law
Replies: 5
Views: 229

Re: Hess's Law

Thanks! So how does this equation and idea relate to specific heat? Is specific heat involved in the equation to find enthalpy because it is needed in each step of a specific reaction?
by Renee Delamater 2H
Wed Jan 17, 2018 9:28 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.51 energy "released"
Replies: 4
Views: 184

Re: 8.51 energy "released"

I agree; technically the energy is released so it makes sense that it would be a negative number (because exothermic reactions are negative) but since it is in relation to the outside receiving the energy, it is gaining a positive amount of energy.
by Renee Delamater 2H
Wed Jan 17, 2018 9:21 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hess's Law
Replies: 5
Views: 229

Hess's Law

What exactly does Hess's Law state?
by Renee Delamater 2H
Thu Jan 11, 2018 10:39 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Equations
Replies: 6
Views: 255

Re: Equations

The heat of fusion uses unit of mass (the specific heat of fusion), and the molar heat of fusion is the enthalpy change per amount of substance referred to in moles. Using the example of H2O, you first find the mass of ice melted with the volume of melt. Then you calculate the energy (in joules) rel...
by Renee Delamater 2H
Thu Jan 11, 2018 10:31 am
Forum: Phase Changes & Related Calculations
Topic: Phase Changes: Molecular Level [ENDORSED]
Replies: 2
Views: 144

Re: Phase Changes: Molecular Level [ENDORSED]

During the face changes, the part of the phase graph with a constant slope is when the phases are in the process of changing. For instance, the line between the slopes showing liquid water and ice is as the H20 is freezing into a solid.
by Renee Delamater 2H
Mon Jan 08, 2018 7:30 pm
Forum: Phase Changes & Related Calculations
Topic: Enthalpy and Temperature [ENDORSED]
Replies: 4
Views: 209

Re: Enthalpy and Temperature [ENDORSED]

When the temperature is greater, there is more heat and therefore more energy. I think that this would cause enthalpy to also increase.

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