CHEMISTRY COMMUNITY

Cole Doolittle 2K

I do not think it really matters which one you write it as. It is however important to know that K is equal to k1/k'1 if you are only given the values of k1 and k'1 and not a value for K.

Cole Doolittle 2K

If there are hydronium ions in your balanced redox reaction, they should be included in your cell diagram.

Cole Doolittle 2K

I do not believe that derivation/integration would be asked of us, simply how to apply the derived formulas to problems.

Cole Doolittle 2K

I am also confused. I understand that delta H would be negative if you are freezing and thus losing heat, but wouldn't delta S also be negative if you are losing entropy going from a liquid to a solid? Thanks in advance!

Cole Doolittle 2K

You would want to use a cathode with the weakest reducing power (strongest oxidizing power) and an anode with the weakest oxidizing power (strongest reducing power).

Cole Doolittle 2K

H+ is included in the cell diagram, but H2O (l) and electrons are not.

Cole Doolittle 2K

Typically we would use the half-life formula to determine how long an element has been decaying.

Cole Doolittle 2K

I think he shows us the derivation to establish some kind of fundamentals, but it really just confuses the [censored] out of me. I don't think we would ever be asked to derive them on a test, just to apply them to problems similar to homework and tests.

Cole Doolittle 2K

This sounds like the question is just trying to be tricky. We were taught to write anode on the left and cathode on the right.

Cole Doolittle 2K

Given the reduction half reactions, you will use the appendix to find E naught values. The lower E naught value is the anode because it is the stronger reducing agent. Then, to get E naught of the cell you do cathode - anode = E naught cell

Cole Doolittle 2K

K cannot be negative because you can't have a negative concentration

Cole Doolittle 2K

Molecules of the same phase in the cell diagram are written in the order: oxidized, reduced

Cole Doolittle 2K

I think the most important thing is that the electrons are on opposite sides in reduction vs oxidation half reactions, but given that that is how we did it in class I assume that is how we should do it on an exam.

Cole Doolittle 2K

n is moles so I assume it will either be a given value or we will need to convert to moles from a given mass of a compound or element.

Cole Doolittle 2K

Because the equation is delta G = -nFE, a positive cell potential (or E value) results in a negative delta G, and thus a spontaneous reaction.

Cole Doolittle 2K

K is the equilibrium constant. Concentration of products at equilibrium over the concentration of reactants at equilibrium.

Cole Doolittle 2K

I'm pretty sure R is the ideal gas constant

Cole Doolittle 2K

Entropy is a state function and thus increases or decreases in a phase change. As said above, solids have the lowest entropy, then liquid, and gases have the highest entropy.

Cole Doolittle 2K

In a closed system, only energy can exchange with surroundings. An example is a sealed beaker of water. You cannot change the volume but you can heat the container because it isn't insulated and thus change the energy.

Cole Doolittle 2K

I believe this is because the formula is w = - P (delta V). If it is expansion, delta V will be positive and thus work negative. In compression delta V is negative and thus work is positive.

Cole Doolittle 2K

The units should be mol/L (Molarity) because it's asking for the concentration.

Cole Doolittle 2K

You may be able to if you are given a concentration: n/V, or moles/liter.

Cole Doolittle 2K

You can use approximations if the Ka value is less than 1x10^-3. You should check to see that it was appropriate to use approximation by seeing if the equilibrium concentration is less than 5% of the initial concentration.

Cole Doolittle 2K

I'm not sure if there is an index of these values. They should be given to you by problem or the problem may tell you to look at a table to find the pKa or Ka values. Also if you are given the Ka you know the pKa and vice versa.

Cole Doolittle 2K

bars are a unit of pressure just like atm or TORR

Cole Doolittle 2K

The equation is 2H2O → H3O + + OH-. The significance is that shows that water is amphoteric (able to react as an acid and a base).

Cole Doolittle 2K

You have to dilute the solution by multiplying .025M(200ml/250ml). Then, take the negative log of that new concentration and you should get the correct pH.

Cole Doolittle 2K

Kp = Kc x (RT) ^ stoichiometric coefficient

In general, Kp uses partial pressures and Kc uses concentrations

Cole Doolittle 2K

Kc: concentration of products over concentration of reactants when at equilibrium
Kp: partial pressures of products over partial pressures of reactants when at equilibrium

Cole Doolittle 2K

So far we have typically used ICE tables to calculate equilibrium concentrations of the products and reactants when given a Kc and initial concentrations.

CHEMISTRY COMMUNITY

Search found 30 matches

Re: K vs k1/k'1

Re: Hydronium

Re: Integration/Derivation

Re: Spontaneous Reaction

Re: Cell Potential

Re: Cell Diagram

Re: Half-Life

Re: Rate Laws

Re: 6M. 1 7th Edition

Re: Calculating E naught

Re: negative and k

Re: Galvanic Cell Diagram [ENDORSED]

Re: Oxidation and Reduction

Re: n value

Re: Spontaneous cell reaction

Re: Gibbs Free Energy

Re: Van't Hoff Equation

Re: Entropy

Re: Open vs Closed System

Re: Work sign changes

Re: Quiz 1 Number 3c

Re: Calculating partial pressure

Re: Approximations for ICE

Re: pKa values

Re: Bars vs. Molarity

Re: Autoprotolysis

Re: HW Q

Re: Equations

Re: Difference between Kc, Kp, and K

Re: ICE table question