CHEMISTRY COMMUNITY

SophiaKohlhoff4B

does left to right or up and down have a greater effect on radii?

SophiaKohlhoff4B

Is acid rain formed from SO2 or SO4?

SophiaKohlhoff4B

They just go in alphabetical order, disregarding the prefixes.

SophiaKohlhoff4B

Dissociation energy is the energy required to break a bond. When bonds are formed, energy is released bc the molecule becomes more stable. When bonds are broken, energy must be added (positive) as to bring the atoms to less stable states (higher energy levels).

SophiaKohlhoff4B

If the final asks for the intermolecular forces in a molecule, can we always write that London forces are present or are there cases where they are not?

SophiaKohlhoff4B

Is the answer automatically wrong if lone pairs are not separated from the shared pairs of electrons? for instance, if something has 3 shared pairs of electrons and 2 lone pairs, can it only be written as AX3E2 or can you write it as AX5? The VSEPR formula calls to use A for the central atom, X for...

SophiaKohlhoff4B

What is an example of a compound that has a delta bond?

SophiaKohlhoff4B

It is important to draw the resonance for a molecule because it demonstrates that the actual bond lengths are the average of the bond lengths. Do we need to include something to show the bond lengths are an average and the same or is that implied when we draw the resonance structures? I don't think...

SophiaKohlhoff4B

Imelda Mena 3I wrote:Does anyone know if the different types of bonds will be on test 3? Thanks in advance!

I think so. The syllabus says that test 3 will cover section 3.12 in the end of bonding and all of Molecular Shape and Structure.

SophiaKohlhoff4B

It is important to draw the resonance for a molecule because it demonstrates that the actual bond lengths are the average of the bond lengths.

SophiaKohlhoff4B

If dipole moments, caused by differences in electronegativity, do not cancel, then the molecule will be polar. The atom with the greater electronegativity will get the delta negative and the atom with the lower electronegativity will have the delta positive. Electronegativity follows the general tre...

SophiaKohlhoff4B

I don't think Dr. Lavelle has mentioned the trigonal pyramidal shape, but it is the answer to question 4.7 in the 6th edition. It also says that the bond angles are 109.5 degrees (which is the same angle as a tetrahedral shape) so are these two shapes the same? The trigonal pyramidal I think is the...

SophiaKohlhoff4B

Dipoles do not have much influence over Lewis structures, they are only important in VSEPR models.

SophiaKohlhoff4B

To find the mass of a molecule however, you need to take the molar mass, found under the atomic symbol on the periodic table, and divide by Avogadro's number, 6.022X10^23.

SophiaKohlhoff4B

The reaction for combustion will be compound + O2 --> CO2 + H2O

SophiaKohlhoff4B

This is also important in questions asking a question similar to: how many electrons can have quantum numbers n=4, l=1? Because each configuration of n,l,m can have 2 possible Ms values.

SophiaKohlhoff4B

The formal charges could be useful in determining the most favorable arrangement of atoms in a molecule, and therefore the most likely Lewis structure. The Lewis structure with formal charges closest to zero is, typically, most likely because it usually represents the lowest-energy arrangement of at...

SophiaKohlhoff4B

Yes, London forces are "universal" because they act between all molecules. They are the only interactions between non-polar molecules. The strength of the London forces typically increases as molar mass increases.

SophiaKohlhoff4B

Non-metals typically have high electronegativity. They acquire electrons to fill their valence shell and, therefore, they form anions.

SophiaKohlhoff4B

Is there a trend for electron affinities?

SophiaKohlhoff4B

Ionic radii decreases across a period (from left to right on the period table). The closer an electron is to the nucleus, the more difficult it will be to remove, therefore requiring a greater ionization energy.

SophiaKohlhoff4B

To think this through the relation of energy and wavelength formulaically, consider the formula: wavelength = hc/E. Because h and c are both constants, the numerator will always equal the product of Planck's constant and the speed of light. Wavelength will therefore decrease as energy, E, increases....

SophiaKohlhoff4B

Will all constants be provided on the test?

SophiaKohlhoff4B

The work function (Ф) is the energy required to remove an electron from a metal. If the energy of the photon, represented by hv, is greater than the work function, the electron is ejected with kinetic energy (1/2 me x v^2) equaling the difference in the energy supplied by the photon and the work fun...

SophiaKohlhoff4B

I have found it is easiest to balance the least occurring elements first, starting in compounds consisting of the most elements. Then, I leave compounds such as O2 for last because it is easy to balance the lone element of oxygen according to what the rest of the equation calls for.

SophiaKohlhoff4B

For week 3 homework, do we have to answer questions from a specific outline?

SophiaKohlhoff4B

This formula is especially useful in diluting stock solutions.

SophiaKohlhoff4B

Actual yield will always be less than theoretical yield due to side reactions, impurities, etc.
Percent yield = (Actual yield/theoretical yield) x100

SophiaKohlhoff4B

For problems involving multiplication/division, the product/quotient should be rounded to the least number of sig figs of the factors. For problems involving addition/subtraction, the sum/difference should be rounded to the least number of sig figs after the decimal.

SophiaKohlhoff4B

With regards to molarity when diluting a solution, it is important to remember that the moles of solute remain the same. The unknown volume or mass can be computed by plugging known values into: M(initial)xV(initial) = M(final)xV(final)

CHEMISTRY COMMUNITY

Search found 30 matches

Re: Size and Polarizability

Re: Acid Rain

Re: order of ligand name

Re: Dissociation energy

Re: Is Hydrogen Bonding a type of Dipole-Dipole Interaction?

Re: lone pairs

Re: Delta Bonds

Re: Drawing resonance

Re: Energy of Interactions

Re: Drawing resonance

Re: Polar vs. Nonpolar

Re: molecular shapes

Re: Dipole

Re: Molar Mass

Re: Combustion Equation

Re: Ms quantum number relevancy on the midterm

Re: Formal Charge and Lewis Structures

Re: london forces

Re: Covalent Bonds

Re: Ionization Energy and Electron Affinity

Re: Ionization Energy [ENDORSED]

Re: Questions about the energy level [ENDORSED]

Re: Wavelength Calculations

Re: Kinetic energy

Re: Balancing reactions tips

Re: Homework for Week 2

Re: Formula M1V1=M2V2 [ENDORSED]

Re: Actual yield [ENDORSED]

Re: knowing how many sig figs to use

Re: MOLARITY