CHEMISTRY COMMUNITY

Yousif Jafar 1G

We multiply the other side by the negative to get 1/[A]t - 1/[A]0.

Yousif Jafar 1G

It utilizes redox reactions to coat a surface.

Yousif Jafar 1G

Also if gibbs free energy is zero, the free energy of the reactants equals that of the products

Yousif Jafar 1G

Activation energy is the minimum quantity of energy which the reacting species must possess in order to undergo a specified reaction to reach the products and this can be shown in an energy profile diagram by showing the energy of the reactants, the energy needed to overcome the Activation energy, a...

Yousif Jafar 1G

One of the TA's said in a review session that there should be one or two problems on it.

Yousif Jafar 1G

Order of a reaction is just the relationship between the rate and the concentration of the reactant. It is calculated utilizing a chart similar to that in the notes where we see how concentration affects the rate of the experiment we are running under different scenarios. A first order reaction is a...

Yousif Jafar 1G

A first order reaction is a reaction based solely on one reactant with order of one, but a second order reaction is either two reactant each with order of one or one reactant with an order of two. Order of a reaction is just the relationship between the rate and the concentration of the reactant. It...

Yousif Jafar 1G

Yeah so pretty much kinetics that we cover attempts to evaluate how different factors such as temperature and concentration affect our reaction rate, and we will probably use this information in 14BL as we conduct different labs.

Yousif Jafar 1G

Either way we are covering the nernst equation on Monday so you could ask Ben because he is there at lecture.

Yousif Jafar 1G

You would have to draw it out. If its cis, the molecules can only be in three positions of the octahedral and the top and bottom and the two diagonals. However, if they are trans, they can be in any of the six positions and there are two molecules that are trans for those six positions so twelve pos...

Yousif Jafar 1G

galvanic cell is practically another word for an spontaneous reaction and voltaic is just another name.

Yousif Jafar 1G

The equilibrium constant only comes into play when we use this equation at equilibrium

Yousif Jafar 1G

No you just use it when you are given the other variables

Yousif Jafar 1G

unless it is isothermal and irreversible, you use the other formulas were change in entropy is =nRlnT2/T1

Yousif Jafar 1G

Thank you

Yousif Jafar 1G

there is also a pdf on Facebook

Yousif Jafar 1G

When does delta H = q ?

Yousif Jafar 1G

Also, for irreversible reactions, they completely go to products where they do not revert to the reactants

Yousif Jafar 1G

I think we just have to know how to read the graph and draw information from it

Yousif Jafar 1G

What does heat capacity depend on?

Yousif Jafar 1G

yeah or we look it up in the book

Yousif Jafar 1G

it is because it is a state function so it can be added

Yousif Jafar 1G

Because the bond enthalpies of other molecules are averages

Yousif Jafar 1G

by using the fact that the [H3O+][OH-]=Kw

Yousif Jafar 1G

because in the reactants there are less moles of gas because C is a solid so it is more favorable

Yousif Jafar 1G

Can anyone explain the concept of a strong acid being leveled?

Yousif Jafar 1G

The Van't Hoff equation is practically just the relationship between temperature, the independent value, and the Keq, the dependent value.

Yousif Jafar 1G

bar, atm, and PSI can all be used as a unit for pressure in our Kp values

Yousif Jafar 1G

Kc should be used when talking about concentrations and it is just under the umbrella of Keq which could be either Kp or Kc.

Yousif Jafar 1G

CH3COOH is an arrhenius acid because it can act as a proton donor. However, I think that NH3 can be justified as an Arrhenius base because it does increase the [OH-] as a product.

Yousif Jafar 1G

for that question the ratios are not derived from the overall molecules. What you have to do is find the moles of C in CO2, the moles of H in H2O and then add those two together. This number will be subtracted from 1 because that is the weight of your unknown compound, giving you the grams of O whic...

Yousif Jafar 1G

also for more practice on naming you can search churro and do Lyndon's practice test which has naming

Yousif Jafar 1G

NH3 actually has a charge of 0 because of the formal charges (all hydrogens=0 and N=0), so like stated, the 2- charge of sulfate would be balanced by a +3 charge of Co to make it +1

Yousif Jafar 1G

Dear Dr. Lavelle,

Thank you so much for everything this quarter. Your class has been one of my favorites and I really appreciate your positive attitude and smile you bring to every lecture. Can't wait to have you again next quarter!

Yousif Jafar 1G

I do not think they have a relation you can do either.

Yousif Jafar 1G

2sp3 is the combination of the s and p orbitals into a hybrid orbital sp3 and it is the s and p orbitals of the molecule's n=2 shell

Yousif Jafar 1G

Hybridization is the mixture of the different atomic orbitals, so sp3 is a combination of the s orbitals and the p orbitals. Also, the number of atomic orbitals are equal to the hybrid orbitals.

Yousif Jafar 1G

I think we just need to understand the premises of pi and sigma bonds and the drawings allow you to see where they exist in 3D space.

Yousif Jafar 1G

Like Lavelle said we do not need to memorize the experimental data just that the bond angle is slightly less than what the electron density would suggest.

Yousif Jafar 1G

For Vespr its more about orientation of the bonds than the type so I don't think there is a way to dictate double bonds. When you draw in lone pairs just show an electron cloud.

Yousif Jafar 1G

Yeah i think they still have discussion on wednesday

Yousif Jafar 1G

The larger the atom, the farther the bond is from the nucleus. This makes the attraction weaker as the inner electrons shield the valence electrons in the bond and they feel less pull to the larger molecules. This causes the bond to be weaker.

Yousif Jafar 1G

The resonance structures with the most formal charges equal to or close to 0 are the ones that contribute the most to the resonance hybrid.

Yousif Jafar 1G

Electronegativity is the tendency to attract an electron. So, as you move across a period there are more protons, so the electronegativity increases. The electronegativity decreases as you move down because of the increased distance between the electron and the nucleus and more electrons are shieldi...

Yousif Jafar 1G

Do we need to know today's lecture on dipole moments for the midterm?

Yousif Jafar 1G

What periodic trends do we need to know for the midterm?

Yousif Jafar 1G

How is electronegativity calculated?

Yousif Jafar 1G

Yeah we go over bonding. We began from the fundamentals and I think next class we will continue to expand on chemical bonding.

Yousif Jafar 1G

The covalent radius is 1/2 the distance between the centers of neighboring atoms and is when two atoms (nonmetals) are joined by covalent bonds.

Yousif Jafar 1G

Is there a particular order for Lewis dot structures?

Yousif Jafar 1G

For the test, we just have to know of it conceptually because he stated multiple times that we do not have to understand how to calculate anything using it as that is for the physical sciences.

Yousif Jafar 1G

For the Rydberg equation, it is usually used when you want to determine the wavelength of the radiation when an electron goes from n-initial to n-final. to do that you find the frequency, nu (the one that looks like a v) and from there you utilize c=lambda/nu to find the wavelength. You can relate t...

Yousif Jafar 1G

Due to the electrostatic interactions between the nucleus and the electrons in the various orbitals, the further the electron is from the nucleus, the higher its energy. Because the s-orbital is shielding the p-orbital in the same shell, the electrons of the p-orbital will have a higher energy becau...

Yousif Jafar 1G

No, the kinetic energy that you derive from Ek=1/2mv^2 can be related to frequency by using the formula Ek=hv-ϕ. So practically what this equation does is it sets the kinetic energy of the ejected electron equal to the energy supplied by the photon minus the work function (threshold value) that is n...

Yousif Jafar 1G

Does c=Lambda(v) apply in quantum mechanics?

Yousif Jafar 1G

So conceptually, this problem is similar to the graphs that Dr. Lavelle showed us in class. When the wavelength is shorter, so UV waves, the electron is falling from an elevated state to n=1. However when you go to a larger wavelength, visible light (400nm-700nm), the electron is falling from an ele...

Yousif Jafar 1G

Moles are just a measurement kind of like a dozen. You can define what the moles, or dozen, is of so it could be atoms, molecules, formula units, or donuts. The number is the same regardless of what thing its describing.

Yousif Jafar 1G

I actually use a different method. I try balancing by matching singular elements and their coefficients to that of a compound because the equation is easier to deal with when it is single elements and not multiple comprising a compound.

Yousif Jafar 1G

I think it will be because we discussed it in lecture. The main concept is that you create water and carbon dioxide from the reactant and oxygen, and you balance the equation from there.

Search found 59 matches