CHEMISTRY COMMUNITY

Elizabeth Harty 1A

you add the exponents for the overall order

Elizabeth Harty 1A

Usually what is covered in lecture

Elizabeth Harty 1A

Kelvin

Elizabeth Harty 1A

Thank you for all your help Lavelle!

Elizabeth Harty 1A

How do you do #5?

Elizabeth Harty 1A

Is W always zero for irreversible expansion?

Elizabeth Harty 1A

How do you know which reactions to compare?

Elizabeth Harty 1A

I think its because the entire reaction depends on the slowest step.

Elizabeth Harty 1A

How do we apply these different rates?

Elizabeth Harty 1A

He said we're only doing pre-equlbrium analysis

Elizabeth Harty 1A

providing a alternate pathway and weakening bonds

Elizabeth Harty 1A

How do you know which is anode/cathode if both species is decreasing in oxidation state for instance?

Elizabeth Harty 1A

Can someone explain how it was known to write the equations in this way when it was written as reversible?
Thanks

Elizabeth Harty 1A

When the reaction is reversible how do you know how to write which is the anode and which the cathode?

Elizabeth Harty 1A

Is this material covered on test 2?

Elizabeth Harty 1A

For these type of reactions what does it mean if the reaction is spontaneous?

Elizabeth Harty 1A

What is the difference between delta g naught and delta g?

Elizabeth Harty 1A

Appendix 2B in textbook

Elizabeth Harty 1A

I don't think we really talked about it but it ranks chemical species according to their standard electrode potentials.

Elizabeth Harty 1A

https://www.britannica.com/science/electromotive-force

Elizabeth Harty 1A

When a system does work the value is negative

Elizabeth Harty 1A

What is the Nernst equation used for

Elizabeth Harty 1A

What does max cell potential mean?

Elizabeth Harty 1A

"a thermodynamic quantity equal to the enthalpy (of a system or process) minus the product of the entropy and the absolute temperature."

Elizabeth Harty 1A

The heat lost by the water (indicated by the negative sign) is equal to the heat gained by the ice (the positive sign).

Elizabeth Harty 1A

What is this equation used for?

Elizabeth Harty 1A

Increasing the Temp causes the kinetic energy of the particles to increase which makes them able to occupy more possible states at a faster rate therefore increasing entropy.

Elizabeth Harty 1A

because solids aren't included in the equilbrium equation so doesn't affect kC.

Elizabeth Harty 1A

You can look at the sign of delta g. If it is negative its spontaneous if its positive its not.

Elizabeth Harty 1A

I might be wrong but I think work is only done when there is a volume change.

Elizabeth Harty 1A

You just know when to use it.

Elizabeth Harty 1A

I think it depends on the information you're given in the problem and you rearrange accordingly.

Elizabeth Harty 1A

"Extensive properties, such as mass and volume, depend on the amount of matter being measured. Intensive properties, such as density and color, do not depend on the amount of the substance present. "

Elizabeth Harty 1A

In closed system energy can be transferred and matter is constant but in isolated neither matter nor energy can be transferred. An example of a closed system is a sauce pan w/ lid. An example of an isolated is thermos.

Elizabeth Harty 1A

In an isolated system no matter or energy is able to be transferred. I though a bomb calorimeter was a closed system not isolated?

Elizabeth Harty 1A

https://www.quora.com/Can-a-car-radiator-be-considered-as-a-closed-system-or-an-open-system-Thermodynamics#

hey this might help

Elizabeth Harty 1A

No I don't think so, at least not on the class website.

Elizabeth Harty 1A

You use the ln one when the pressure is not constant.

Elizabeth Harty 1A

In the thermodynamics outline what does the bullet point "calculate enthalpy changes from calorimetric data" mean?

Elizabeth Harty 1A

Bomb calorimeters are constructed so that there is a constant volume so no gases escape during the reaction. This makes it a closed system.

Elizabeth Harty 1A

005391550 wrote:an exothermic reaction will release heat which will raise the temperature of the surroundings and an endothermic reaction will therefore do the opposite

if heat is released for exothermic rxns why is delta t negative?

Elizabeth Harty 1A

What is the difference between enthalpy and entropy?

Elizabeth Harty 1A

Calorimeters measure the heat involved in a chemical rxn or physical process. When a liquid loses or gains energy, its temperature changes. The calorimeter (or the simple one you use in the lab) measures the temperature change for the liquid and the mass to determine the amount of energy lost or gai...

Elizabeth Harty 1A

it has more energy bc it has the energy of boiling water and the energy needs to transition from vapor to liquid (as it touches you)

Elizabeth Harty 1A

Why do you include the mass of the copper, I thought you only used the mass of the water?

Elizabeth Harty 1A

With a closed system, the mater is constant but every is allowed to be transferred to the surroundings. In an isolated system neither matter nor energy transfer is allowed.

Elizabeth Harty 1A

Water has a very high vapor energy.

Elizabeth Harty 1A

It has to have an effect on volume to effect the direction but it doesn't effect equilibrium constant.

Elizabeth Harty 1A

Chemistry Libretexts is really helpful.

Elizabeth Harty 1A

Yes, every chemical reaction can theoretically be in equilibrium.

Elizabeth Harty 1A

it has to do with the energy stored in the bonds and the lack of temperature signifies and phase transition

Elizabeth Harty 1A

positive delta H means endothermic, negative delta H means exothermic.

Elizabeth Harty 1A

You don't need to memorize but should know the differences and converting.

Elizabeth Harty 1A

Its temperature dependent

Elizabeth Harty 1A

Are the calculations the same regardless of whether its concentration of partial pressure?

Elizabeth Harty 1A

What approximation is it talking about?

Elizabeth Harty 1A

This might help

Elizabeth Harty 1A

How do we know when we need to use an ICE table vs when we can just use the equation of products over reactants?

Elizabeth Harty 1A

What are the units for kC and kP?

Elizabeth Harty 1A

What exactly is the reaction quotient?

Elizabeth Harty 1A

When doing the equations for k why does Lavelle put a Pp in from of the reactants/products? I know it stands for partial pressure but what exactly is partial pressure?

Elizabeth Harty 1A

In lecture, Lavelle said that if the value is between the two limits neither the reactant nor the product is favored and it is in a sort of intermediate state.

Elizabeth Harty 1A

Although they are both calculated the same way, they are compared to determine which way the reaction will proceed.

Elizabeth Harty 1A

How do you do number 34?

Elizabeth Harty 1A

How do you know if something is amphiprotic?

Elizabeth Harty 1A

How do you know if there are sigma bonds available for rotation?

Elizabeth Harty 1A

005162520 wrote:Does chlorine get replaced by water or nitrogen from guanine base pair?

I think the water

Elizabeth Harty 1A

Camille 4I wrote:Why is cisplatin square planar and not tetrahedral?

its both

Elizabeth Harty 1A

Why is it that the Ka is bigger for the first dissociation in comparison to the second?

Elizabeth Harty 1A

Based on problem 6A.17 from the homework, how do you determine if an oxide is acidic basic or amphoteric?

Elizabeth Harty 1A

Coordination # and oxidation # aren't necessarily the same.

Elizabeth Harty 1A

You order them alphabetically ignoring greek prefixes.

Elizabeth Harty 1A

I understand the definition of Bronsted and Lewis acids and bases but how do you identify if an acid or base is Lewis or Bronsted when it is in a reaction? Does this determine how you then deal with the reaction. In the reaction, the one giving off a proton is the acid and the one reacting with tha...

Elizabeth Harty 1A

Do they check every Sunday or at the end?

Elizabeth Harty 1A

Ashley Osorio wrote:So because they (typically) completely dissolve in water, they have no Ka value. Can only strong acids do this then? Have no Ka value?

Do you mean as opposed to bases?

Elizabeth Harty 1A

Yes we have to memorize the table he emailed to us.

Elizabeth Harty 1A

You can look at lone pairs.

Elizabeth Harty 1A

I think you have to memorize them.

Elizabeth Harty 1A

When doing acids you just add a proton and increase the charge respectively.

Elizabeth Harty 1A

Coordinate covalent bonds also often happen when there are exceptions to the octet rule like for boron.

Elizabeth Harty 1A

What exactly is a dipole moment?

Elizabeth Harty 1A

Why are lone pairs more likely to be found in certain places?

Elizabeth Harty 1A

Why are lone pairs more likely to be found in certain places?

Elizabeth Harty 1A

The formal charges should be minimized but they also have to add up to the overall charge of the molecule.

Elizabeth Harty 1A

You might look at the sizes and the electronegativity differences

Elizabeth Harty 1A

They have an odd number of electrons and are highly reactive

Elizabeth Harty 1A

Are all tests worth the same amount? (besides midterm of course)

Elizabeth Harty 1A

It is meant to show the hydrogen bond between two water molecules.

Elizabeth Harty 1A

My TA said if you do the shorthand (with the arrows) instead of actually drawing all the structures you should write an explanation to show that you know how many there are

Elizabeth Harty 1A

At this point in what we have learned I don't think it matters too much.

Elizabeth Harty 1A

Also hydrogen bonds are one of the strongest types of bonds

Elizabeth Harty 1A

I thought that the units for joules had the second to the power of negative 2?

Elizabeth Harty 1A

is momentum mass times velocity?

Elizabeth Harty 1A

Can someone explain how to do #5 from this problem set?

Elizabeth Harty 1A

It depends on what the compound is and how you can minimize formal charge

Elizabeth Harty 1A

For these you just add one to the d orbital and take one from the 4s to make it 4s^1

Elizabeth Harty 1A

A resonance hybrid is used to show all of the resonance structures combined

Elizabeth Harty 1A

It happens when there is unequal charge density or separation of positive and negative charge. You can use it to measure polarity of a molecule

Elizabeth Harty 1A

I'm pretty sure the formal charge doesn't change because you aren't changing connectivity just arrangement? Also you can use the dotted lines to draw resonance to show the change in bonds.

Elizabeth Harty 1A

You want to overall formal charge to equal zero when you take into consideration all formal charges of atoms in species

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