Search found 32 matches

by Nico Edgar 4L
Sat Mar 16, 2019 12:00 pm
Forum: Administrative Questions and Class Announcements
Topic: LYNDON'S PORK RAMEN REVIEW
Replies: 37
Views: 2598

Re: LYNDON'S PORK RAMEN REVIEW

I thought E standard was always 0 for concentration cells. Why is this not the case in 1?
by Nico Edgar 4L
Wed Mar 13, 2019 2:27 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Molecularity
Replies: 2
Views: 165

Molecularity

For Molecularity, can we just assume it is the number of reactants? I know the definition, but is it just number of reactants?
by Nico Edgar 4L
Wed Mar 13, 2019 2:26 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Activation Energies
Replies: 3
Views: 78

Re: Activation Energies

They are both the same, choose which ever feels more natural to you and the one that makes more sense.
by Nico Edgar 4L
Wed Mar 13, 2019 2:25 pm
Forum: General Rate Laws
Topic: Rate equations to know
Replies: 5
Views: 78

Re: Rate equations to know

One thing to note is that we should also know how to rearrange the integrated rate laws to get the form that the question is asking for. Chapter 7A does a good job of showing the different forms.
by Nico Edgar 4L
Fri Mar 08, 2019 11:14 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: k & K
Replies: 18
Views: 379

Re: k & K

k is a rate constant dependent on the reaction you have. K is the equilibrium constant.
by Nico Edgar 4L
Fri Mar 08, 2019 11:12 am
Forum: General Rate Laws
Topic: Graph of ln[A] against time
Replies: 4
Views: 75

Re: Graph of ln[A] against time

This graph is linear if it is a first order reaction, as in that case the reaction rate is in the form of a linear equation or line.
by Nico Edgar 4L
Fri Mar 08, 2019 11:11 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Reaction Rate Orders
Replies: 4
Views: 87

Re: Reaction Rate Orders

It is the combined order of the reactants
by Nico Edgar 4L
Mon Feb 25, 2019 2:05 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L3 7th edition
Replies: 1
Views: 27

6L3 7th edition

I can't figure out how to do part d of this problem. Do I have to use h2o to balance?
by Nico Edgar 4L
Mon Feb 25, 2019 2:04 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell diagrams [ENDORSED]
Replies: 1
Views: 70

Cell diagrams [ENDORSED]

How do we know how to order the components of a cell diagram? And when do we know if a component is or isn't part of the diagram?
by Nico Edgar 4L
Mon Feb 25, 2019 2:03 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Moles in -nFEcell
Replies: 5
Views: 114

Moles in -nFEcell

How do we know what n is? Is it just the sum of the coefficients of the products?
by Nico Edgar 4L
Wed Feb 20, 2019 3:01 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Spontaneity in the Gibbs Eqn
Replies: 4
Views: 70

Spontaneity in the Gibbs Eqn

If a reaction has negative delta H and negative delta S, will it be spontaneous at high or low temperatures??
by Nico Edgar 4L
Wed Feb 20, 2019 2:58 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 4J3 7th Edition
Replies: 1
Views: 40

4J3 7th Edition

For this problem, do we use the enthalpy and entropy of vaporization for NH3? I seem to be getting the incorrect answer and am not sure why.
by Nico Edgar 4L
Wed Feb 20, 2019 2:56 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Spontaneous vs Not Spontaneous
Replies: 7
Views: 111

Re: Spontaneous vs Not Spontaneous

Gibbs free Energy is our best indicator of spontaneity. If it is negative the reaction will be spontaneous, if not it will be non-spontaneous.
by Nico Edgar 4L
Wed Feb 13, 2019 10:54 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Edition 7 number 4F11
Replies: 2
Views: 64

Re: Edition 7 number 4F11

Also I can't seem to get the right answer. Do we find the Entropy change through temperature and then the Entropy change through Volume and sum them?
by Nico Edgar 4L
Tue Feb 12, 2019 10:48 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Cp and Cv
Replies: 3
Views: 64

Re: Cp and Cv

Also since entropy is a state function, even if there is a volume change and a temperature change, we can still use Cv as we end up summing the two entropy changes. We assume that volume was constant over the temperature range so we can use Cv. See 4F11 in the 7th edition.
by Nico Edgar 4L
Tue Feb 12, 2019 10:44 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Thermodynamics
Replies: 1
Views: 55

Re: Thermodynamics

No, I think the ones we need to know are given on the sheet at least for monatomic molecules. Then they are easy to memorize as they just increase by one.
by Nico Edgar 4L
Tue Feb 12, 2019 10:37 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Edition 7 number 4F11
Replies: 2
Views: 64

Re: Edition 7 number 4F11

I am not entirely sure why it was ok to ignore the moles of N2 gas. It might be because we are at ideal conditions and can just assume it is 1? But, in example 4F5 they also ignore the moles and point to the eqaution delta S= C ln(T2/T1). I think it is because we treat the heat capacity as constant ...
by Nico Edgar 4L
Mon Feb 04, 2019 3:26 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Degeneracy
Replies: 2
Views: 51

Degeneracy

What exactly is degeneracy and how does it differ from entropy??
by Nico Edgar 4L
Mon Feb 04, 2019 3:24 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: ^U=q+w
Replies: 1
Views: 50

^U=q+w

Why is qp+w equal to change in enthalpy -P*change in volume? And why is change in enthalpy -P*change in volume equal to change in moles *R*T?
by Nico Edgar 4L
Mon Feb 04, 2019 3:20 pm
Forum: Calculating Work of Expansion
Topic: Work of Expansion
Replies: 2
Views: 45

Work of Expansion

Does Work of expansion always have a change in volume? and does this mean that the pressure is always constant for our calculations?
by Nico Edgar 4L
Tue Jan 29, 2019 11:21 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat capacity vs. enthalpy
Replies: 4
Views: 84

Re: Heat capacity vs. enthalpy

Heat Capacity is the amount of energy needed to heat an amount of something by 1 degree celsius. Enthalpy is the energy released or gained during a reaction.
by Nico Edgar 4L
Tue Jan 29, 2019 11:20 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: HW Week4
Replies: 4
Views: 90

Re: HW Week4

We have not gone over work in class yet so we cant really do 4A, look over 4C and 4D, I found better/more clear problems in those! I think we just arent doing this unit in order.
by Nico Edgar 4L
Tue Jan 29, 2019 11:17 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Qsystem+Qsurr=0?
Replies: 6
Views: 128

Re: Qsystem+Qsurr=0?

The equation is based on the fact that the surrondings can either lose or gain energy due to the reaction happening in the system. So if the reaction in exothermic, it releases energy and heats the surrondings, so the Q of the system would be negative and the Q surr would be positive. We assume our ...
by Nico Edgar 4L
Sun Jan 27, 2019 6:59 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 4A.9 7th Edition
Replies: 1
Views: 29

4A.9 7th Edition

Any idea on how to calculate the final temperature of 50.7 g of water at 22 C when a block of Cu of 20g at 100C is placed in it?
by Nico Edgar 4L
Thu Jan 24, 2019 5:06 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Equilibrium Composition
Replies: 2
Views: 53

Equilibrium Composition

What is the difference between calculating the equilibrium composition and finding the percent Ionization in an Acid Base Rxn?
by Nico Edgar 4L
Thu Jan 24, 2019 5:01 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Ka and pH
Replies: 6
Views: 112

Re: Ka and pH

No there is not. Ka/B just let you find the concentration of H+/OH- which in turn lets you find the pH.
by Nico Edgar 4L
Thu Jan 24, 2019 4:59 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Le Chateliers Priniciple
Replies: 9
Views: 260

Le Chateliers Priniciple

Will a change in pressure cause the reaction to shift one way or another?
by Nico Edgar 4L
Wed Jan 16, 2019 3:43 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Weak Acids and Bases
Replies: 6
Views: 168

Re: Weak Acids and Bases

Oh so if the x is smaller, than the normal concentration of water then you need to add it to 10^-7 because that will give you the accurate pH, a pH very close to 7. Since 10^-9 is smaller, this means that you would add the x you got to the normal concentration of water.
by Nico Edgar 4L
Wed Jan 16, 2019 3:39 pm
Forum: Conjugate Acids & Bases
Topic: Cojugate Acids and Bases
Replies: 5
Views: 270

Re: Cojugate Acids and Bases

The conjugate acids and bases are just the products of a acid base reaction. If you wrote the reverse reaction the conjugate base would just be the base. It's not like an base can only be a base or conjugate base.
by Nico Edgar 4L
Sun Jan 13, 2019 1:20 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Exothermic Reactions
Replies: 9
Views: 144

Re: Exothermic Reactions

An exothermic reaction will release energy, so the products have less energy than the reactants. An endothermic reaction will need energy, so the products have more energy then the reactants.
by Nico Edgar 4L
Fri Jan 11, 2019 3:22 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: equilibrium
Replies: 3
Views: 69

Re: equilibrium

If you know the equilibrium reaction and the value of Keq for that reaction, you can figure out which way the reaction is moving when given any concentrations in that reaction. Just plug those non-eq values into the Keq equation and if your value is less than the Keq the reaction is moving toward th...
by Nico Edgar 4L
Fri Jan 11, 2019 3:17 pm
Forum: Ideal Gases
Topic: units for PV=nRT
Replies: 5
Views: 108

Re: units for PV=nRT

The Units for PV=nRT depend on what you are solving for. Normally V will be in liters, P will be in atm, T will ALWAYS be in Kelvin, and n will be in moles. R is a constant whose value depends on the units of the other components. Say you were solving for P with the units given above, the equation w...

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