CHEMISTRY COMMUNITY

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Go through the past exams that we have had. Understand all your mistakes from the midterm and tests.

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I believe they'll be available to see during the second week of winter quarter

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I think he said he might curve it based on the final exam scores.

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It was pretty boring. There was no music playing during the exam. I could've really used some Cudi to get me through that.

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Amphoteric is more general than amophiprotic

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It's just so you know that the oxygen is what is bonded and not the hydrogen.

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A chelate is when a ligand has bonded to multiple sites.

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It tells you the oxidation state.

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You just have to memorize them.

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Yes. We will probably be given the formula first.

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What is the significance of the coordination number?

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Why are coordination compounds typically octahedral?

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First is ligand. Then transition metal cation name. If there are anoins, they go after.

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What is a ligand? Where does it bond?

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Why does VSEPR theory not apply to coordination compounds?

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Lone pairs are delocalized electrons which have a larger electron density than localized bonded electrons. Because of this, they tend to have a greater repulsion than bonded electrons and push other electrons further away.

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Draw the most stable Lewis structure (as we were required to do before) and determine the molecular shape and bond angle for it.

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We need to know what the molecular shape for a given compound is, how to draw its Lewis structure, and the bond angles between all atoms in the molecule.

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Yes. It is important to memorize and be able to determine the molecular shape for any given compound.

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Draw lewis structures and then look at electronegativity differences amongst bonds to draw dipole moments. If the dipole moments do not cancel, the molecule is polar.

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You want to minimize the magnitude of formal charges for the sum of the atoms. You want to maximize the number of formal charges of 0.

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Why is one sigma and one pi bond formed instead of two sigma bonds?

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Why are pi bonds weaker than sigma bonds?

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Is it necessary to memorize the exact numerical bond angle value?

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Why do lone pairs repel other electrons more than electrons in bonds?

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Can someone explain why there's an inverse relationship between the certainty of momentum and position for electrons?

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Is there a way that we are supposed to show whether a compound has resonance? Are we supposed to do the double arrow?

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Is electronegativity a measure of an element's desire for a new electron or how strongly it's holding onto the electrons it already has?

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Typically, we are looking for multiples of 2 (#.5), 3 (#.33, #.66), or 4 (#.25, #.75) so we can determine whether or not it is necessary to multiply up. For the purposes of this class, it won't be anything ambiguous.

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The outermost (valence) electrons are typically the ones that do stuff. They're the ones that are involved in bonding and when electrons are removed, it is the outermost ones that are taken off of the atom. Because it is a cation, that means it lost an electron (the one with the highest energy level).

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emaad_3H

Can someone explain how a molecule has equal bond length when some are single and others are double?

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For there to be an unpaired electron, there must be an odd number of valence electrons. Each "pair" of electrons is 2 electrons which means that in the case with bromine where there are 7 valence electrons, there are 3 pairs and 1 left over which means there is 1 unpaired electron.

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Fluorine is the most electronegative because if you went further to the right or higher up, you'd reach noble gases. Electronegativity is a measure of a tendency for an atom to attract an electron. Noble gases already have a full octet or in the case of helium 2 electrons and do not need any more el...

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Why is a formal charge of 0 preferred?

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There's no way to determine which orientation the orbital has. We simply use the different subscripts to differentiate them not to necessarily identify each one.

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Why do we use noble gases to shorten the electron configuration description of multi-electron atoms?

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If the principal quantum number can go past 4 and the the orbital angular momentum quantum number can go up to a value of (n-1) but also represents the shape of the orbitals, does that mean that there are orbitals beyond the f subshell? What would that look like?

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Why is the energy of an electron a negative value?

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Can someone explain what the Balmer and Lyman series are and what the significance of them is?

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If a question requires many calculations (addition/subtraction AND multiplication/division) then at what point are you supposed to follow the sig fig rules? Do you base it on the given numbers or do you do it at each step before reaching the answer?

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Why do larger objects tend to behave less like a wave compared to smaller objects?

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Why do electrons only exist in quantum energies? Why are they not continuous in their distance from the nucleus?

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Are we expected to know the molecular formula of a compound based on just its name. For example, if we're told "magnesium citrate reacts with..." are we supposed to know that magnesium citrate is C6H6MgO7?

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What does it mean when we say that light acts as a wave and as a particle?

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When can you use the equation M1V1=M2V2? Are there certain scenarios where you have to convert to moles in order to solve for dilution problems?

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Can temperature be a reason why one element is in excess over the other? I know temperature has an effect on reaction rate, but can it affect whether or not a reaction goes to completion? And if so, do we need to take it into account right now?

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The law of conservation of mass states that for any closed system, the mass of the system must remain constant. Atoms cannot be created or destroyed in a reaction. The confusion might lie in the fact that different molecules are created. The atoms are just rearranged and form different bonds than th...

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What are some reasons why the actual yield for an experimental reaction is not equal to the theoretical yield? Do we need to be prepared to explain why this happened if given a lab scenario?

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If given percent mass composition of a compound and the molecular mass of the final compound, can I multiply the total mass by the percentage of each of the elements' mass composition and then convert from grams to moles in order to obtain the molecular formula and then get the empirical formula by ...

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If I am using the M1V1=M2V2 dilution equation and I am given M1, M2, and V2, and the final answer is asked to be in milliliters, do I still have to convert the final volume into liters to get V1 in terms of liters or can I leave it in milliliters and get my answer in millimeters?

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