CHEMISTRY COMMUNITY

Eesha Chattopadhyay 2K

Strong acids have a higher percent ionization than weak acids, so there is more H30 present in solutions with strong acids, causing them to have a lower pH.

Eesha Chattopadhyay 2K

You use the 8.314 value because it allows you to cancel out the units properly.

Eesha Chattopadhyay 2K

State functions are functions that only consider the initial and final states, not the path that is taken to obtain those states. An example of a state property is displacement, whereas the non-state property would be the total distance traveled.

Eesha Chattopadhyay 2K

Extensive properties are independent of the amount of a substance, intensive properties rely on the mass (or amount)

Eesha Chattopadhyay 2K

Whichever side does not have an electrode uses platinum as its electrode

Eesha Chattopadhyay 2K

The reaction with the more positive Ecell is has a higher oxidizing power, the more negative has a higher reducing power.

Eesha Chattopadhyay 2K

Galvanic cells are cells that use spontaneous reactions. Electrolytic cells use non-spontaneous reactions.

Eesha Chattopadhyay 2K

The Gibbs free energy is the energy available to do work.

Eesha Chattopadhyay 2K

n is the number of moles of electrons that are transferred.

Eesha Chattopadhyay 2K

When the solution is acidic, you balance the hydrogen ions by adding an H+ to the other side. When the solution is basic, you balance the hydrogen by adding an H20 to the side that needs the hydrogen and a OH- on the other side so that the side with the H20 has a net higher number of hydrogens.

Eesha Chattopadhyay 2K

The lower the Gibbs free energy of a reaction is, the more stable its products are.

Eesha Chattopadhyay 2K

As long as the equation is balanced, they can be on either side of the equation.

Eesha Chattopadhyay 2K

The cathode is usually the one being reduced and the another is the one that is being oxidized. Because of this, the scenario you're describing is not possible.

Eesha Chattopadhyay 2K

delta G=-nFE, so if there is a positive cell potential (E) then delta G is negative, making it a spontaneous reaction.

Eesha Chattopadhyay 2K

Can we also use the ln(k2/k1)=-delta H standard/R[1/t1 -1/t2] to solve this problem or do we have to find the separate standard G to find the values of K?

Eesha Chattopadhyay 2K

In the past Lavelle has usually given the charges of the ions, but I think it's helpful to know some of them just in case.

Eesha Chattopadhyay 2K

A half reaction is a reaction that displays either the oxidation or the reduction in a redox reaction.

Eesha Chattopadhyay 2K

The cathode is the reaction that is being reduced, and the anode is the reaction that is being oxidized. Usually they put the anode on the left and the cathode on the right but not necessarily always.

Eesha Chattopadhyay 2K

The Van't Hoff Equation is used to find the new equilibrium constant of a solution at a different temperature, given the K at a different temperature.

Eesha Chattopadhyay 2K

Standard cell potentials are the potentials of cells when they are under standard conditions (298K, 1ATM).

Eesha Chattopadhyay 2K

An isochloric process is one that has constant volume.

Eesha Chattopadhyay 2K

Yes, this can be done because it is also a state function.

Eesha Chattopadhyay 2K

Lavelle does not curve his tests but sometimes in the past he has adjusted the final grades.

Eesha Chattopadhyay 2K

Delta S is the measure of the entropy of a system, this means that a negative value would mean that the system becomes more orderly as a result of that process.

Eesha Chattopadhyay 2K

The Vant Hoff equation relates the equilibrium constant to the change in temperature when given the heat of formation for the process.

Eesha Chattopadhyay 2K

Can someone explain why the reaction SO2(g)+Br2(g)+2 H2O(l) --> H2SO4(aq) +2 HBr(aq) would cause a decrease in the entropy of the system?

Eesha Chattopadhyay 2K

Because the problem describes an irreversible expansion with a constant external pressure, you use the equation w=-P(ex)(deltaV). The delta V is equal to the area of the region compressed or expanded times the distance compressed. Therefore the diameter given is used to find the area of the region c...

Eesha Chattopadhyay 2K

The sum of the work done on/by a system and the heat given off/absorbed by a system is equal to the enthalpy of a reaction. This being said, when there is a constant pressure, the delta H value is simply equal to the heat transfer.

Eesha Chattopadhyay 2K

The equipartition theorem is the idea that the average value of each quadratic contribution to the energy of a molecule in a sample with temperature T is 1/2*k*T.

Eesha Chattopadhyay 2K

if the k is smaller than 10^3, then the x in the ice box can be disregarded in the denominator.

Eesha Chattopadhyay 2K

A reversible process is one that can be reversed by an infinitely small change in a variable. For example, if the external pressure is equal to the pressure of the gas in the system, then even an infinitesimal decrease in external pressure will cause the piston to move out (work of expansion) and an...

Eesha Chattopadhyay 2K

What is the relationship between whether a system is in equilibrium and whether or not the changes are reversible or irreversible?

Eesha Chattopadhyay 2K

In a closed system, energy can be exchanged with its surroundings while matter cannot. In an isolated system, neither mass nor energy can be exchanged with the surrounding universe.

Eesha Chattopadhyay 2K

An example of an isolated system is the combustion of glucose within a bomb calorimeter.

Eesha Chattopadhyay 2K

An example of something that is not a state function is heat (q) because it is energy in transit and does not depend on the initial and final values.

Eesha Chattopadhyay 2K

I understand that degeneracy is the number of ways that a given energy state is achieved but what exactly is degeneracy used for?

Eesha Chattopadhyay 2K

No, calculating the enthalpy of a phase change will not be negative.

Eesha Chattopadhyay 2K

The proper method is to calculate the enthalpy, then add the enthalpy of the phase change.

Eesha Chattopadhyay 2K

being additive means that different enthalpies of different reactions can be added. this is true because enthalpy is a state function.

Eesha Chattopadhyay 2K

state properties are those that are determined by its current state, independent on the path taken to obtain that state.

Eesha Chattopadhyay 2K

Exothermic reactions have a negative delta H because the enthalpy of the products have less enthalpy than the reactants, and delta H is the difference between the products and the reactants, making the delta H negative. In endothermic reactions the products have a higher H than the reactants, making...

Eesha Chattopadhyay 2K

Yes, if the ka is smaller that 10^-3, but if the percentage ionization is greater than 5% then you should go back and do the entire quadratic equation.

Eesha Chattopadhyay 2K

Yes, pH+pOH =14, so this can be used to determine the other if you have either the pH or the pOH.

Eesha Chattopadhyay 2K

It will ask specifically for pH or pOH if that's what they want. Otherwise, just give in the units of what they're asking for.

Eesha Chattopadhyay 2K

The X can only be taken out if it is very small and would not make a significant impact on the overall calculation, but this is usually only in either the numerator or denominator, rarely both. Therefore not all of the Xs can be considered negligible.

Eesha Chattopadhyay 2K

The equilibrium sign is used in order to display that both the forward and reverse reactions are occurring. At equilibrium, this happens at the same rate, but the sign just symbolizes the presence of both reactions.

Eesha Chattopadhyay 2K

We use units for concentration, but don't use it for the equilibrium constant.

Eesha Chattopadhyay 2K

If you aren't using the K of the forward reaction, then yes you just switch the products and reactants in the expression.

Eesha Chattopadhyay 2K

You can only use pV=nRT if there is low pressure and high temperature.

Eesha Chattopadhyay 2K

In class, Dr. Lavelle mentioned briefly saying that technically K is the ratio if the activities of the products and reactants, which is unit-less.

Eesha Chattopadhyay 2K

Yes, this is basically the only use.

Eesha Chattopadhyay 2K

Yes, that is the definition of a pi bond.

Eesha Chattopadhyay 2K

You would use -ate if the the complex that you are naming is anionic.

Eesha Chattopadhyay 2K

According to the textbook, if an element's name on the periodic table is based on their latin name, then that latin name is used in naming the coordination complex. This is also why copper is represented by "cuprate".

Eesha Chattopadhyay 2K

Cisplatin is a helpful chemotherapy drug because it stops rapid cell division. However, it has recently stopped being used as frequently because of its inability to target malignant cells, meaning that rapidly dividing healthy cells (such as hair follicles) are also affected.

Eesha Chattopadhyay 2K

Amphoteric compounds have both basic and acidic properties. Since As2O3 exhibits properties of both it is indeed an amphoteric compound.

Eesha Chattopadhyay 2K

There is no difference in the naming of the H20 molecule.

Eesha Chattopadhyay 2K

Sigma bonds have the ability to rotate, while pi bonds do not have this ability so the pi bonds will always break

Eesha Chattopadhyay 2K

An amphoteric compound is one that can act both as an acid and as a base.

Eesha Chattopadhyay 2K

An amphiprotic substance is a amphoteric substance that transfers H+ ions.

Eesha Chattopadhyay 2K

What exactly is the difference between Lewis acids/bases and Bronsted acids/ bases?

Eesha Chattopadhyay 2K

Lewis acids donate protons, while Lewis bases accept them.

Eesha Chattopadhyay 2K

If a molecule has two lone pairs, whether or not it is bent or linear depends on the total number of regions of electron density.

Eesha Chattopadhyay 2K

Is there a way to tell how many ligands can attach to a transition metal if we don't know the oxidation state of the transition metal?

Eesha Chattopadhyay 2K

I'm pretty sure all transition metals can form coordination compounds.

Eesha Chattopadhyay 2K

Hybridization occurs in order to equalize the imbalance in the energy levels of electrons. The energy level of the hybridized orbitals lies in between the s and p (or d) orbitals.

Eesha Chattopadhyay 2K

The number of ligands that attach must neutralize the charge of the transition metal, so the number that can attach depends on the charge of the central transition metal.

Eesha Chattopadhyay 2K

In order for a hydrogen bond to form, it must be covalently bonded to Fluorine, Oxygen, or Nitrogen and it must be with a Fluorine, Oxygen, or Nitrogen atom with a lone pair. For example, the hydrogens in H2O interact with the Oxygen in water molecules (which has 2 lone pairs). Also, since Hydrogen ...

Eesha Chattopadhyay 2K

The order of which of the 3 bonds is sigma and which are pi isn't important, even the book doesn't spend very much time on that. I think we probably just have to know that a triple bond has 1 sigma bond and 2 pi bonds

Eesha Chattopadhyay 2K

This means that the atoms with pi bonds (and the ones connected to atoms with pi bonds) are all in the same plane, since they cannot rotate like sigma bonds can.

Eesha Chattopadhyay 2K

The book uses A in all of its other VSEPR formulas other than in this question so I'd say it's safe to assume that the latter is also correct.

Eesha Chattopadhyay 2K

You basically predict the shape around each central atom, so in the case of b, the shape is tetrahedral around the carbon atoms, and the bond angle around the beryllium is 180. You still use all the same rules as if this molecule had only one central atom.

Eesha Chattopadhyay 2K

If you add the kinetic energy to the threshold energy, you get the energy per photon that's being used in this photoelectric experiment. From there you use E=hv and c=v(wavelength) to find the wavelength.

Eesha Chattopadhyay 2K

The photoelectric effect is the one that supports the article properties of light, while de broglie supported the wave like properties. The photoelectric effect talks about how intensity doesn't affect the energy of light, where if there were solely wake like properties, this would not be the case.

Eesha Chattopadhyay 2K

Yes, they do occur in nature. An example of one in nature is the Carbon-Nitrogen bond in amino acids.

Eesha Chattopadhyay 2K

Yes, they occur in all atoms.

Eesha Chattopadhyay 2K

How do you determine which element in a radical gets the lone electron? I'm looking at 2C.5 part a which is asking you to draw ClO. How do I know if the last electron does on Cl or O?

Eesha Chattopadhyay 2K

A resonance structure is used to demonstrate that there are not fixed positions of electrons and that electrons do move around.

Eesha Chattopadhyay 2K

The strength of a bond is measured by its dissociation energy. Longer bonds are easily broken and more likely to be involved in a reaction, while shorter bonds are harder to break and therefore less reactive. The longer the bond, the weaker it is.

Eesha Chattopadhyay 2K

An electron would have a faster speed (if they have the same wavelength) because it has a much smaller mass than a proton.

Eesha Chattopadhyay 2K

When you convert the number of moles to grams, its usually the number of grams used in the reaction.

Eesha Chattopadhyay 2K

the M stands for mega.

Eesha Chattopadhyay 2K

Fluorine is the most electronegative atom because it has 7 valence electrons (5 in the 2 p shell) and therefore is close to the optimal electron configuration, making it have a higher affinity for gaining another electron to reach the stable octet configuration.

Eesha Chattopadhyay 2K

Double bonds are shorter than single bonds because the bonds are stronger an therefore they pull the atoms closer together.

Eesha Chattopadhyay 2K

In order to find the equation you have to look at the charges for magnesium ions and for arsenic ions. Magnesium ions have a charge of 2+ and arsenic ions have a charge of 3- so in order to balance the charges there must be three magnesium atoms and 2 arsenic atoms.

Eesha Chattopadhyay 2K

Yes, they should have the sane electronegativity because elements that are more electronegative have a higher change of gaining electrons and atoms that are isoelectronic have equal numbers of electrons.

Eesha Chattopadhyay 2K

Resonance structures are necessary because the e- is not just occupying that one formation. The electrons are actually in a position that is an average of the possible structures so saying that one is correct is not true. We draw all of them because it shows that there is more than one possibility o...

Eesha Chattopadhyay 2K

The experiment consisted of passing a beam of silver atoms through a magnetic field. When this was done, it split into two beams because the electrons that had an upward spin and those that had a downward spin created their own magnetic fields. The stern and Gerlach experiment determined the presenc...

Eesha Chattopadhyay 2K

There is kinetic energy when the energy of the photons being aimed at the metal is greater than the work function. Therefore, if the energy of the photon is equal to the work function there is no kinetic energy. The kinetic energy is the excess energy from the photon therefore if there is no excess ...

Eesha Chattopadhyay 2K

The nodal plane of an orbital is where there is no probability that you will find an electron. This means that there are regions on the p- and d- orbitals where it is impossible to find an electron.

Eesha Chattopadhyay 2K

If there is no kinetic energy, then the energy required to remove an electron from the metal is equal to the energy of the photon beam being directed at the metal. from there you use the equation E=hv to find the frequency, then c= (wavelength)(frequency) to find the greatest wavelength of light tha...

Eesha Chattopadhyay 2K

You might be able to get a copy of previous years' midterm from the test bank at the Student Activities Center.

Eesha Chattopadhyay 2K

Those coefficents before the "p" and "s" refer to the "n" number which usually corresponds to the period number except with the "d" block with is usually "n-1".

Eesha Chattopadhyay 2K

Ionic bonds are stronger than covalent bonds

Eesha Chattopadhyay 2K

A photon is a light particle and its lack of mass can be explained by wave particle duality and the fact that the photon acts as both a particle and a wave.

Eesha Chattopadhyay 2K

Accuracy is how close your value is to the actual value while precision are multiple values close to each other regardless of the actual value.

Eesha Chattopadhyay 2K

For addition use the number of decimal places and for multiplication use the lowest number of sig figs

Eesha Chattopadhyay 2K

The Rydberg equation represents the frequency associated with an electron moving from one energy level to another. The frequency is equal to the Rydberg constant multiplied by the inverse of the final minus initial energy levels. You can use the equation when trying to find the frequency of the wave...

Eesha Chattopadhyay 2K

I think the most accurate way to go about taking masses from a periodic table is by taking the entire number that's given on the sheet and using in your calculations. This way you are sure to prevent rounding error and can then use the sig figs from the problem to round later on

Eesha Chattopadhyay 2K

Use the balanced equation to determine how many moles of product can be made with that many moles AgCl. Then multiply that number by the molar mass that you've given to determine how many grams of that product has been created

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