CHEMISTRY COMMUNITY

Ricardo Martin 1J

What is the temperature in standard conditions? Is it 0 degrees C or 25 degrees C?

Ricardo Martin 1J

Because 02 occurs naturally.

Ricardo Martin 1J

Yes it will cover Gibbs free energy and what we cover in lecture during week 7.

Ricardo Martin 1J

Yes the r in Gr corresponded to reactants and the p in Gp to products.

Ricardo Martin 1J

Yes the reaction is only spontaneous if the free energy is negative (-).

Ricardo Martin 1J

Yes delta G is a state function because it is defined by other state functions.

Ricardo Martin 1J

If free energy is negative (-) then the reaction is spontaneous and if it is positive (+) then the reaction is not spontaneous (requires energy).

Ricardo Martin 1J

Since H20 is a liquid it would not be used in the calculation of the equilibrium constant and ICE table.

Ricardo Martin 1J

S=0 in a perfect crystal (T= 0 Kelvin)

Ricardo Martin 1J

When work is done BY the system w is negative and when work is done ON the system w is positive.

Ricardo Martin 1J

It is open because matter and energy can be transferred in and out of it.

Ricardo Martin 1J

I have found it helpful to do all the homework problems and attend peer learning sessions.

Ricardo Martin 1J

A closed system does not allow for matter transfer, but allows for energy transfer. An isolated system does not allow for both matter and energy transfer.

Ricardo Martin 1J

Yes, the equation sheet, constants, and periodic table are always provided for tests and exams.

Ricardo Martin 1J

pH is the concentration f hydrogen ions in the solution.

Ricardo Martin 1J

E stands for equilibrium concentration.

Ricardo Martin 1J

Isolated system does not allow for the transfer of matter or energy while a closed system can transfer energy (but not matter).

Ricardo Martin 1J

J/C(mol) - Joules over Celsius times mole(s)

Ricardo Martin 1J

An isolated system does not allow transfer of matter and energy.

Ricardo Martin 1J

Condensation releases heat.

Ricardo Martin 1J

A state function is a property that does not rely on the path taken from the initial state to the final state.

Ricardo Martin 1J

If Q > K then a reverse reaction is favored.
If Q < K then a forward reaction is favored.

Ricardo Martin 1J

No, there is no change to a reaction if an inert gas is added.

Ricardo Martin 1J

How can you tell if a molecule is an acid or a base (based on its chemical formula)?

Ricardo Martin 1J

The 5% rule is just used to check if your approximation is valid. You can assume that you are allowed to approximate when the k value is <10^-3.

Ricardo Martin 1J

I do not think you need to memorize because you can tell by the K value, however it would not hurt to know common strong acids and bases.

Ricardo Martin 1J

It is only equal to 10^-14 when water is at 25 degrees C. However, I believe (at least so far) our reactions will be given in this condition.

Ricardo Martin 1J

Removing products would only affect Q and K would remain unchanged.

Ricardo Martin 1J

You can find out by writing out the chemical equation.

Ricardo Martin 1J

Yes, the composition of the reaction mixture remains constant when at equilibrium.

Ricardo Martin 1J

Personally, I find it helpful to do all problems assigned for homework and attending review sessions during the week and also the ones right before midterms and finals.

Ricardo Martin 1J

Yes, since hybridization relates to the # of areas of electron density and lone pairs are considered an area of electron density, then lone pairs are taken into consideration for hybridization.

Ricardo Martin 1J

4 areas of electron density equals sp3 hybridization.

Ricardo Martin 1J

No, they do not change the hybridization of an atom, only areas of electron density change it.

Ricardo Martin 1J

sp3 should be enough.

Ricardo Martin 1J

Trigonal planar is considered sp^2 hybridization because it has 3 regions of electron density.

Ricardo Martin 1J

If a Lewis structure is symmetric it is non-polar and if it is not symmetric it is polar.

Ricardo Martin 1J

Yes bent structures are polar.

Ricardo Martin 1J

Ethan Breaux 1J wrote:Is VSEPR Notation also referred to as VSEPR Formula?

I believe they are the same thing.

Ricardo Martin 1J

Lone pairs are able to repel bond pairs more than bond pairs are able to repel each other, therefore the bond angles are made smaller by lone pairs.

Ricardo Martin 1J

The electron arrangement would be tetrahedral, however since one is a lone pair the shape is trigonal pyramidal.

Ricardo Martin 1J

Bent and angular are the same shape

Ricardo Martin 1J

Yes this is a bent shape with bond angles less than 109.5

Ricardo Martin 1J

Ethan Breaux 1J wrote:Maybe I'm just reading this wrong but are you referring to see saw?

I don't think it's see saw, I think it is T-shape because I believe the structure being described has 3 bonds and 2 lone pairs, but maybe I also read it wrong.

Ricardo Martin 1J

A trick I found helpful is memorizing the VSEPR equations such as AX3E2 and knowing what shape corresponds to those equations because as soon as you drew the Lewis Structure you could conclude the VSEPR equation and therefore concluding the shape. This also helps with knowing the hybridization.

Ricardo Martin 1J

I don't think you have to memorize specific bond lengths but should probably know that a single bond is longer the a double bond which is longer than a triple bond.

Ricardo Martin 1J

Oxygen is more electronegative than carbon which attracts the electrons to them usually giving it a negative charge.

Ricardo Martin 1J

The polarizability of a molecule depends the size of the molecule and the number of electrons that the molecule has.

Ricardo Martin 1J

The most stable configuration for a resonance structure would be one where the formal charge is closest to 0, which could be find with the equation FC= V (valence electrons) - (L (lone pair electrons) + s/2 (shared electrons divided by 2).

Ricardo Martin 1J

Difference in electronegativity defines ionic character.

Ricardo Martin 1J

What is the difference between ionic and covalent bonds?

Ricardo Martin 1J

Test 2 covers everything from lecture #4 to lecture #10 (October 5 to October 19) which is the quantum world to multi-electron atoms.

Ricardo Martin 1J

what does m with subscript l tell you about the atom?

Ricardo Martin 1J

I understand that Px Py Pz tell you something about the orientation of the orbital, however, what about the orientation does it tell you about, most specifically what does Pz tell you?

Ricardo Martin 1J

I say just do it just in case and it is pretty well-explained in the book if you do take a look.

Ricardo Martin 1J

Why does the Heisenberg Indeterminacy equation have a greater than or equal to sign instead of an equal sign? Will this always be the case?

Ricardo Martin 1J

Can someone explain to me what a nodal plane is and its function?

Ricardo Martin 1J

An angstrom is equivalent to 1x10^-10 m and Dr. Lavelle stated that it would be common to find wavelengths to the ^-10m, therefore, the angstrom is used for convenience in writing these lengths.

Ricardo Martin 1J

Hz and s^-1 are interchangeable because they are equivalent. I see Hz used more often than s^-1, but I doubt that you will be marked wrong for using one or the other.

Ricardo Martin 1J

I believe we will be given all the equations and constants for every test/exam we take, but I believe you should still memorize the formulas because I find that it helps me to know exactly what to use when reading a problem. However, the formulas given on the test could be good for double checking t...

Ricardo Martin 1J

When a problem asks for a ratio would we also need to make sure all values of the ratio are in terms of significant figures? For example in exercise F.9 (of the 7th edition), the ratio of the answer would be 1O:2.67C:2.67H, however, the lowest number of significant figures from the problem is three ...

Ricardo Martin 1J

Do all our final answers need to be converted to the base SI unit (ex:meter, kilogram, mole) or do we just use the closest prefix to it? And if we leave our answer in the base SI unit and do not use a prefix simplifying the value would our answer be wrong even if both answers would be mathematically...

Ricardo Martin 1J

You do not need to do it every time, you can use any amount you want for mass to solve for how much the percentage accounts for, however, since percent means a part of ONE HUNDRED, then it is much easier to use 100g as the mass because you would only need to change the percent sign to grams.

Search found 63 matches