CHEMISTRY COMMUNITY

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Tetrahedral is an atom that has 4 bonds. This means that the 2s orbital and the 2p orbital hybridize to form sp3. To determine a molecule's hybridization, just count the number of bonds/lone pairs on the central atom (1 bond= s, 2 bond= sp, 3 bond= p2, 4 bond= sp3, 5 bond= sp3d, 6 bond= sp3d2, etc.)

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I'm not 100% sure but I think the class is just graded on that rubric and not curved.

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They are the same but for exams, I would use bent for 2 bonds and one lone pair and angular for when it is 1 bond and 3 lone pairs.

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The first covalent bond between atoms is a sigma bond. You can only have one sigma bond between two atoms. A single bond has one sigma, a double bond has one sigma and one pi. Pi bonds usually occur in p-orbitals (never s orbitals).

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The A tells us which is the central atom, the X tells us the ligands/bonds attached to the central atom, and E tells us the nonbonding electron pairs (and lowercase e shows nonbonding lone electrons). So, for example, AX2E could be SO2 because S is the central atom, it has two bonds with two Os, and...

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I asked a few students that have taken the class before and they said that is cumulative, but there won't be so many questions on the first few weeks material. For studying, I would suggest focusing mostly on the material after the midterm, but definitely do practice questions/ review all weeks mate...

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I assume that for the next exam/final, we will only be asked to determine the bond angles when also asked to draw the Lewis Structure for partial points. So, you'd draw the dot structure then determine the VSEPR shape and corresponding bond angles. Finding the dot structure is really important becau...

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Non-polar molecules are attracted through London forces and polar molecules are attracted as well, but stronger through dipole-dipole attractions. So to determine, look at the electronegativity of the molecule. Also, size can help determine. Smaller molecules tend to have stronger dipole- dipole for...

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Yes I agree there can only be one sigma bond between two atoms in a molecule and two in a pi bond, but in one molecule there can be multiple.

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The amount of electronegativity of the hydrogen bond will make it the strongest.

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Solids have the lowest kinetic energy (because their particles are moving the slowest) so they are closely attracted to each other. So solids have the highest intermolecular force because their particles are attracted to each other the most. Then liquid, then gas.

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Yes I agree. Energy is released to break bonds, so it is positive. It is leaving the system. Energy is needed to make bonds, so it is negative. It is using up energy around to break it.

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I think if he asks a question about bond lengths it will be referring to the overall trends/ how each atom connects to each other (polar, nonpolar, ionic).

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After creating the Lewis Structure for the question, always do the formal charges around it to make sure that they are as close to 0 as possible! Even though it might look like it adds up and makes sense it may not be stable. In this example, the single bonded oxygens are unstable because they still...

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Also, P, S, and cl are specific exceptions that Dr. Lavelle said we needed to know for the exam that take more than 8 valence electrons!

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The crystal field theory explains how electron orbitals (usually d or f) get broken down by a static electric field. This field is created by anions to help take the electrons of these subshells and thus break it down. This is dependant on the shape of the orbital as well as its charge.

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The answers above give you the correct answer, but just make sure that you use parenthesis in your calculator! I know that in my experience I sometimes get the wrong answer when I'm dividing by something like Planck's Constant, it can get confusing if you are dividing while multiplying by 10^34, so ...

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This is because that each element is different in the number of electrons it wants to take/give away when bonding. So for Cu, it has 2 valence electrons, so it would want to give up those 2 to make it stable, but not more than is in its valence ring. It also might want to take electrons to make it s...

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I think we only need to know the conceptual ideas about this equation/how it's used/why it's important in chemistry, but we won't need to compute it.

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I would say that although the placement doesn't necessarily matter in the Lewis Structure, as a rule of thumb make sure that your placement next to the other atom is precise because that's where your bond will be and it makes it less visually confusing for grading. Fill out the other 3 sides before ...

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If electrons get pulled into the nucleus when there is a higher negative charge (giving them a smaller size), why are cations smaller than anions? Wouldn't it be that with fewer electrons it would be more spaced out/larger?

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Can Lewis structures be used to construct the molecular structure of the element? So Lewis Structures tell you the valence electron # of the atoms, so it can help tell you the position the atom has in a molecule. So because molecular structures are dependent on the spatial orientation of covalent b...

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For me, the best way to take notes is to write down the powerpoint and insert different extra notes he says in class. After class though, I find it really helpful to watch his video module (which is a lecture with roughly the same powerpoint) as a refresher and take any notes I missed while writing ...

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You'll commonly see it written as Å in this class for exams, etc, and it is used to measure the size of atoms/molecules, the length of chemical bonds, or the wavelengths of electrochem radiation. It is equivalent to 1.0 × 10-10 meters, but its not an SI unit. For example, hydrogen is about 0.5 Å, wh...

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Can someone explain this answer? Particularly the last portion.

34. If an electron (mass 9.11 x 10-31 kg) has an associated wavelength of 7.28 x 10-9 m, what is its speed? Is your answer reasonable, why?

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Why is theoretical yield greater than actual yield in chemical reactions?

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I think the professor said that we don't need to know polyatomic ions as of right now, and not for the first test. We may go further in depth about them later in class, though.

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I think that it will probably be 8 questions like stated above with one for each topic of the review (empirical formula, molecular formula, balancing chemical equations, limiting reactant calculations, and molarity/ dilution of a solution).

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I think that if you can try and do it the way it was taught in class it would be beneficial since we will be graded on partial credit so the steps might be an important factor.

CHEMISTRY COMMUNITY

Search found 29 matches

Re: tetrahedral

Re: Final Grades

Re: Bent vs angular?

Re: Bonds

Re: VSEPR model

Re: Final Exam

Re: Bond Angles

Re: Intermolecular Forces

Re: Sigma/Pi bonds

Re: Hydrogen Bonding [ENDORSED]

Re: States of matter and forces

Re: Bond energy value signs

Re: Bond Lengths

Re: Formal Charge SO42-

Re: What are the octet exceptions?

Re: Electric Field

Re: DeBroglie Equation Post Assessment

Re: Ionization of elements

Re: Application of Equation on test

Re: Dots in Lewis Stucture

Cation/Anion Size

Re: Drawing Lewis Structures with Charges

Re: Note Taking

Re: Angstrom?

Post-Assessment Question 34

Theoretical vs Actual Yield

Re: HW F11

Re: Number of questions on test one [ENDORSED]

Re: different ways to determine limiting reactant