CHEMISTRY COMMUNITY

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15. Determine the molecule's shape and polarity: AX2E2 The answer is bent but it has 2 lone pairs so i'm confused why the molecule would be bent since bent molecules only have 1 lone pair and 2 bonding electron pairs. Why wouldn't the answer be angular since angular molecules have 2 lone pairs and 2...

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Why is HI(aq) a stronger acid than HF(aq)? I thought that since Fluorine wants to fill its octet and Hydrogen wants to share its one electron that would mean HF would be stronger since they would hold on tighter to eachother based on a larger difference in electronegativity, but HI is a stronger aci...

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Strong acids and bases completely dissociate in solution. Therefore, they must have a small change in electronegativity between atoms in order for the molecule to completely dissociate in solution. On the other hand, weak acids and bases may partially dissociate in solution, but they do not complete...

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I'm not sure I understand your question, but covalent bonds can have polar characeristics. Polarizability of molecules bound by covalent bonds is determined by both the size and charge of the atoms.

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My favorite meme

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Brønsted acids are H+ donors while Brønsted bases are H+ acceptors.
Lewis acids accept an e- pair, Lewis bases donate an e- pair.

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Which molecular shapes will we be responsible for knowing for the final? Will we need to know their hybridization and polarity as well?

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by having the shapes memorized, you should be able to figure out the hydridization based on how many regions of electron density there are around the central atom.

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You can determine whether the molecule is polar or nonpolar by first looking at the molecules shape (draw the lewis structure). For elements across from eachother, if their difference in electronegativity is significant enough, then the molecule is polar. Typically, bonds with an electronegativity d...

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In problem 3.45, we are asked to draw the lewis structures that contribute to the resonance hybrid for ClNO2. In the answer, there are only two structures. I was able to make a lot more than 2, does that mean that the other ones I made are not "resonance contributors"? How can I determine ...

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Why is it that an H atom can only have +1/2 and -1/2 spin? What exactly does the value of 1/2 mean?

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Anytime you are given certain amounts of reactants and are asked to find the product, this will be a limiting reactant problem. While it may not say so specifically in the problem, you can know it'a a limiting reactant problem because you can only make as much product as your reactants allow. For ex...

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When you want to draw a lone pair, you should use two dots to represent that. The line is just used for bonds between atoms, also representing 2 electrons. The line representing a bond between two atoms shows the sharing of two electrons between the atoms.

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High polarizability means that the electron cloud can easily be distorted or electrons are more easily pulled away from the central atom. They form bonds with greater covalent character because the electron is pulled further between the two bonding molecules. As polarizability increases, the dispers...

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I agree with @Nienjou Claire. They can have up to ten electrons because that's how many e- are needed to fill the d block.

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I don't think it matters where you put the rest of the elements around the center as long as you satisfy the proper formal charge and octets(or duets).

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When a molecule has multiple resonance structures, it just means that the representation of the actual structure of the molecule is a blend of all the resonance structures, each bond that could be displayed as a double bond has a partial double bond character. This blending of characters is what mak...

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Leading zeroes are never significant. Example: both 0.0009 and .9 have 1 significant figure Trailing zeroes are only significant if they are after a decimal, or are followed by a decimal. Example: 0.900 has 3 sig figs. 900 only has 1 sig fig. however, 900. (notice the decimal at the end) has 3 sig f...

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Does that essentially mean that for multiplication and division we are basing the answer on the least number of sig figs present whereas for addition and subtraction we are basing it on the the least number of decimal places present? Yes, for multiplication and division, your answer will have the s...

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First, find out how many total valence electrons youll need, find the central atom (the atom with the lowest ionization energy), then, fill out the atoms with lone pairs according to the octet rule. Count all the valence electrons, if there are too many, add double bonds as needed and remove the ext...

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I'm not sure I understand your question, but to start, count the valence electrons for each atom in the compound. Next, choose the atom with the lowest ionization energy and this will be the element in the center of the lewis structure. From there, arrange the remaining atoms symmetrically around th...

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The velocity of an electron that is emitted from a metallic surface by a photon is 3.6 x 10^3 km x s^-1. a) what is the wavelength of the ejected electron? In the solutions, they use lambda= h/mv. I just don't understand how the units for mass (kg) cancel out? There's not other mass units in the equ...

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It was kinda short but if you practice all the problems and know how to do them without thinking too hard about what the question, it should be a good amount of time. After finishing all the homework problems (not just 7) I was able to finish the test with 5 minutes left to check my answers.

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Do all of the problems and you should naturally memorize them. Although all equations and constants will be given on the test, it's helpful to memorize them so that you can save time from looking for the formula on the exam.

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It's used to calculate the wavelength using the Planck's constant(h) and the mass of the particle (m).

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I'm not sure I understand your question, but to determine limiting reactant you can convert the grams of both reactants to moles of the same product, the reactant that results in the lesser moles of product will determine how much product is made and is therefore your limiting reactant.

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As long as your answer is correct and you specify which units your answer is in (mL or L) I don't think it matters what you put your answer in unless they specify that they want your answer in specific units.

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I usually make a table on each side of my reaction listing all the elements and how many of each there are for both reactants and products, from there you can see what you need to balance and you can balance the elements that occur only once first and balance elements that are in more than one molec...

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If they give you the reactants and not the products and you're told that its undergoing combustion, you can assume that the reactants are oxygen (O2) as well as the other reactant given. The products of combustion are always H2O and CO2, but sometimes other products will be given. From there, you st...

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For the molecular formula, you count the number of each element, for example 12 Hydrogen, 6 Carbon, and 6 Oxygen. so that would give a molecular formula of C6H12O6, then to find empirical you divide by the lowest common factor, in this case it's 6. so the empirical formula would be CH2O.

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It wouldn't be marked as wrong because rounding rules still apply with sig figs. As long as you didn't round earlier in the problem, it's okay to round your final answer while still following the sig fig rules.

CHEMISTRY COMMUNITY

Search found 31 matches

french toast #15

Question about HF (aq)

Re: Strength of an acid

Re: Polarizability for covalent bonds?

Re: Post All Chemistry Jokes Here

Re: Bronsted vs Lewis Acids and Bases

Molecular Shapes On the Final

Re: Hybridization

Re: 4.27

3.45

ms quantum number

Re: Knowing if it's Limiting Reactions

Re: Dots vs lines to represent electrons

Re: Does being more polarizable= Being stronger?

Re: Exceptions to the Octet

Re: Creating a Lewis Stucture

Re: Understanding Resonance Structures

Re: Zeros in Sig Figs

Re: diference in sig figs

Re: Best way to start Lewis Structures

Re: Order of Dots

1.33 [ENDORSED]

Re: Test Time

Re: Memorizing formulas test 2

Re: DeBroglie

Re: Limiting Reactants

Re: Units - L or mL? [ENDORSED]

Re: Trick to balance?

Re: Balancing Chemical Equations and Combustion

Re: Determining Formulas Based on Molecule

Re: Rounding: when and where?