CHEMISTRY COMMUNITY

Nawal Dandachi 1G

you should always convert to Kelvin

Nawal Dandachi 1G

You should convert temperature to kelvin because you are using R which uses Kelvin.

Nawal Dandachi 1G

I always assume they are the same, but I guess when you are referring to gases, K is Kp, and Kp is not equal to Kc.

Nawal Dandachi 1G

All half equations are written as reduction, so we would flip the anode in order to make the reaction a redox reaction.

Nawal Dandachi 1G

at equilibrium, k=Q, so if you are substituting K for Q in the Nernst equation, then that means that the reaction is at equilibrium.

Nawal Dandachi 1G

I do not think we need to know how to use that.

Nawal Dandachi 1G

yes, we use pt for solid if there is no other solid stated

Nawal Dandachi 1G

isothermal means that temperature is constant therefore internal energy would be 0

Nawal Dandachi 1G

Yes, by knowing the order of the slow step, you can determine the rate of the overall reaction.

Nawal Dandachi 1G

An intermediate is formed in one step and then it is consumed in another step. A catalyst on the other hand is not consumed by the reaction.

Nawal Dandachi 1G

I do not think we would have to develop our own reaction, but we just have to recognize if a "proposed" reaction would correspond to the rate law.

Nawal Dandachi 1G

Because it is the slowest reaction, it is the "rate determining step" and the overall reaction would depend on it.

Nawal Dandachi 1G

i don't think you would include it in the overall reaction if it gets consumed.

Nawal Dandachi 1G

you would just use pOH + pH = 14

Nawal Dandachi 1G

You would use Ecell = Ecell o - RT/nF lnQ where Q would equal to [products]/[reactants] and in that situation, it was [anode]/[cathode]

Nawal Dandachi 1G

Because the rate constant did not change, then it's zero order.

Nawal Dandachi 1G

When you decrease the volume, you're increasing the pressure. Therefore, the reaction would favor the side with less moles, which is the products side. And because the reaction shifts forward, the partial pressure of NO2 will increase.

Nawal Dandachi 1G

Kinetics focuses more on the rate of the reaction while thermodynamics focuses more on whether a reaction will occur or not.

Nawal Dandachi 1G

Intermediates are formed in one reaction and then consumed in the other, so they do not show up in rate laws.

Nawal Dandachi 1G

initial rate is instantaneous rate at the start of a reaction, so we know that there is no product formed. Therefore, we only use the reactants for initial rate.

Nawal Dandachi 1G

Yeah I think it's true for all reactions.

Nawal Dandachi 1G

use commas instead of the "|"

Nawal Dandachi 1G

K' is reverse reaction

Nawal Dandachi 1G

yeah I still think we're supposed to go to the designated location.

Nawal Dandachi 1G

for second order, it should be linear

Nawal Dandachi 1G

i do not think so

Nawal Dandachi 1G

n is the number of moles of electrons transferred

Nawal Dandachi 1G

galvanic cells have a positive standard E and are spontaneous while electrolytic cells have a negative standard E and are nonspontaneous.

Nawal Dandachi 1G

n should be the moles of electrons

Nawal Dandachi 1G

It basically states that acids ionize in water and produce H+ while bases ionize in water to produce OH-.

Nawal Dandachi 1G

Because we need to show that it is being oxidized, so we flip it

Nawal Dandachi 1G

It's a single reaction step. It's when the products are formed in only a single reaction.

Nawal Dandachi 1G

Since they are electric conductors, they will be used to make the electrodes so they do not participate in the reaction.

Nawal Dandachi 1G

n is the number of moles, but if you meant which R you should use, then use 8.314

Nawal Dandachi 1G

"||" = salt bridge while "|" = phase change

Nawal Dandachi 1G

when reactants increase or products decrease, the reaction proceeds forward causing the cell potential to increase. And when the reactants decrease or products increase, the reaction proceeds to the left, causing the cell potential to decrease.

Nawal Dandachi 1G

That happens when the both the reactants and products have the same number of electrons.

Nawal Dandachi 1G

oxidation half reaction would have the electrons in the products while the reduction half reaction would have the electrons in the reactants

Nawal Dandachi 1G

q would be positive if heat is being added to the system and negative if heat is being removed. w would be positive if work is done by the system and negative if work is done on the system.

Nawal Dandachi 1G

it is insignificant when it comes to solids and liquids because there is no change in volume for liquids and solids.

Nawal Dandachi 1G

U is the total energy of a closed system.

Nawal Dandachi 1G

When forming a bond, the system loses energy, and because of the decrease in energy, it must have been released, making it exothermic.

Nawal Dandachi 1G

depending on whether breaking or forming bonds is occurring, you can determine if it's endo or exo.

Nawal Dandachi 1G

partial pressure is a pressure exerted by an individual gas in a mixture

Nawal Dandachi 1G

1000 cal = 1 Cal. and for the nutrition facts, they use Cal which is kcal.

Nawal Dandachi 1G

because k is equal to [products] divided by [reactants], we know that we will end up with a low K value if the [reactant] > [products]. And therefore, there is more reactants

Nawal Dandachi 1G

a low pKa would indicate a strong acid whereas a low pKb would indicate a strong base

Nawal Dandachi 1G

no you do not include liquids and solids

Nawal Dandachi 1G

pKa + pKb = 14, so solve for pKb. After finding pKb, use pKb = -log(kb) to find Kb

Nawal Dandachi 1G

homogenous equilibrium is when all reactants and all products are in the same phase

Nawal Dandachi 1G

when there's a pair of unshared electrons on F-O-N or when there's a hydrogen that is bonded to F-O-N

Nawal Dandachi 1G

where there is a pair of unshared electrons on F-O-N or where there is a hydrogen that is bonded to F-O-N

Nawal Dandachi 1G

Because Dr. Lavelle mentioned it in lecture before, its safer to know it.

Nawal Dandachi 1G

I do not think the amount of hydrogen atoms in the acid affects its strength.

Nawal Dandachi 1G

so basically in H2SO3, we know that it contains SO32- sulfite anion. so we can assume that H2SO3 will donate two protons

Nawal Dandachi 1G

yes, the only thing that has no significance is anything to the left of the decimal point.

Nawal Dandachi 1G

An easier way to remember them is to memorize carbonate and sulfate and then simply add an H which would reduces the charge by 1.

Nawal Dandachi 1G

One way to look at it would be to look at the electronegativity. Since Cl is more electronegative than P it would make HClO4 a stronger acid.

Nawal Dandachi 1G

because it's an electron-pair acceptor

Nawal Dandachi 1G

yeah they are the n values

Nawal Dandachi 1G

yeah i believe so

Nawal Dandachi 1G

yeah single bonds have sigma, double have one sigma and one pi and triple bonds have one sigma and two pi

Nawal Dandachi 1G

Nawal Dandachi 1G

only if they are symmetric and all the atoms attached to the central atom are the same; however, if the atoms attached to the central atom are not the same, then it is polar.

Nawal Dandachi 1G

Since HCl is a strong acid, then we know that it will 100% dissociate, which tells us that the moles of HCl must be equal to the moles of hydronium ions. So, we can use the volume and molarity given to calculate the moles of hydronium ions present. After calculating the number of moles, divide it by...

Nawal Dandachi 1G

Acetic acid is a stronger acid because it is stabilized by resonance.

Nawal Dandachi 1G

the equation he gave was AH <--> A- + H+ and since the pH>pKa, the solution is more alkaline, and the acid will give off H+ to form A-. This basically meant that when AH dissociated, it formed A- which is negative so its negatively charged.

Nawal Dandachi 1G

morphine is basic because it contains a nitrogen with a lone pair. However, BrO- is a conjugate base of a weak acid, so its a stronger base.

Nawal Dandachi 1G

the salt would be calcium bromide, Ca(BrO2)2
HBrO2 + Ca(OH)2 --> H2O + Ca(BrO2)2

Nawal Dandachi 1G

It is considered a strong base because it completely dissociates when it is added to water.

Nawal Dandachi 1G

lewis acid is an electron-pair acceptor while a lewis base is an electron-pair donor.

Nawal Dandachi 1G

I think we should know the common ones, but maybe know them just in case

Nawal Dandachi 1G

because nitrogen contains a lone pair

Nawal Dandachi 1G

I don't think we need to know this

Nawal Dandachi 1G

What did one charged atom say to the other?
I got my ion you!

Nawal Dandachi 1G

AU! THESE JOKES ARE GOLD, SO READ 'EM

Nawal Dandachi 1G

yeah i think so just in case

Nawal Dandachi 1G

He talked about ions as acids and bases.

Nawal Dandachi 1G

it would produce water and potassium acetate.
CH3COOH + K(OH) → H2O + CH3COOK

Nawal Dandachi 1G

HClO2 is a stronger acid than HBrO2 because Cl has a higher electronegativity than Br.

Nawal Dandachi 1G

This is due to carbonate's resonance and lewis structure. Because of its structure, there is 120 degrees between its oxygens so two oxygens can not bind to the same metal making it mono dentate. However, there are some cases where carbonate bonds to different metals which makes it bidentate.

Nawal Dandachi 1G

Some acidic oxides include SO2, CO2, NO2, ClO2 and some basic oxides include CaO and BaO

Nawal Dandachi 1G

When the oxide is added to water and it forms an acid, then it is an acidic oxide. When an oxide is added to water and forms a base, then it is a basic oxide. And when an oxide is added to water and has the ability to form both an acid and base, then it is amphoteric.

Nawal Dandachi 1G

The numbers to the left of the decimal point of the pH has no significance, so for example, a pH of 4.22 would correspond to a concentration that only has two sig figs and not three.

Nawal Dandachi 1G

AH <--> A- + H+
since the pH>pKa, the solution is more alkaline, and the acid will give off H+ to form A-. Therefore, it is negatively charged.

Nawal Dandachi 1G

At the same concentration, weak acids have a higher pH than strong acids because weak acids partially dissociate whereas strong acids fully dissociate. therefore, strong acids have a higher hydronium concentration, and the higher the hydronium concentration, the lower the pH.

Nawal Dandachi 1G

it's any acid that contains oxygen bonded to a hydrogen atom and one or more other elements.

Nawal Dandachi 1G

i think all you need to know is that the stronger the acid is, the weaker its conjugate base. and the stronger the base is, the weaker its conjugate acid is.

Nawal Dandachi 1G

When we look at the conjugate bases for these two acids, the only difference is that there's a methyl group attached adjacent to the carbonyl group in the conjugate base for acetic acid while the conjugate base for formic acid only has a hydrogen attached adjacent to the carbonyl group. The methyl g...

Nawal Dandachi 1G · Re: Final Exam 12/8/2019 and three hours long

12/8/2019 and three hours long

Nawal Dandachi 1G

Since HCl is a strong acid, then we know that it will 100% dissociate, which tells us that the moles of HCl must be equal to the moles of hydronium ions. So, we can use the volume and molarity given to calculate the moles of hydronium ions present. After calculating the number of moles, divide it by...

Nawal Dandachi 1G

Hypobromite ion, BrO-, is a conjugate base of a weak acid, and therefore it must be a strong base. Morphine, C17H19O3N, has a lone pair located on the nitrogen, so it's a weaker base.

Nawal Dandachi 1G

The common aspect in each series is that the energy levels from which an electron starts or returns to is the same for anything in that series. For example, in the Balmer series, the electrons always return from or start from the energy level n=2. Same goes for the Lyman series, where e- start or re...

Nawal Dandachi 1G

Because the emission is ultraviolet, then we know that this transition is happening in the Lyman series. So the final energy level is going to be n=1. The initial energy level could be anything greater than 1. You can then use Rydberg's equation to find n1.

Nawal Dandachi 1G

Yes, you would be able to use a periodic table. So ionization energy increases going up a periodic table and increases going left to right.

Nawal Dandachi 1G

The negative sign of energy just means that the electron of that atom has a lower energy than the free electron which is zero energy.

Nawal Dandachi 1G

For the bohr frequency condition, the equation contains Rydberg's constant (3.29x10^15 Hz); and that constant only works on hydrogen atoms or hydrogen-like atoms such as He+.

Nawal Dandachi 1G

I agree with the commenter before me. The position of the 3d orbital is at a higher level than the 4s orbital; therefore, the 4s orbital would fill up before the the 3d orbital.

Nawal Dandachi 1G

I think they are due on Sunday not sure though

Nawal Dandachi 1G

I got a concentration of 0.13 M of chloride ions. I do not think it matters because when both of these compounds dissociate the mole ratio between the compound and Cl- is 1:1. For example, 1 mole of sodium chloride would dissociate to 1 mole of Na+ and 1 mole of Cl-, so there's no need to separate t...

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