CHEMISTRY COMMUNITY

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Steric strain is caused by unfavorable "steric interactions" between atoms or substituents on a molecule. Steric interactions occur between atoms or molecules that are close to one another; their electron density causes them to repel one another. Basically, atoms don't want to be close to ...

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Someone asked a really similar question in the 11:00 lecture today... I believe the answer was that trans is more stable in most cases, but depending on the size and number of the substituents, this isn't always the case. I think the best option is to picture the alignment of the molecule and try an...

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I think this has to do with substituents. Because the substituent (1-methyl) is on the propyl substituent, the (1-Methylpropyl) part of the chemical name is relating to the substituent of a substituent. Substituents always get priority, so the substituent of the substituent goes before the 4-methyl ...

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This question asks for the redox reaction and maximum potential created by a cell with a 1.0M Ag+ solution in one electrode and a 1.0M Cd2+ solution in another electrode. I understand both half reactions and how to get the cell potential from these equations; however, because the reduction potential...

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The reaction rate is the rate at which a product is produced or a reactant is consumed. The rate constant is the calculated value, K, that is used to calculate the reaction rate. K varies for each reaction and must be calculated to determine a reaction's rate law. Also, the units for K vary dependin...

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A perfect crystal is a "perfectly ordered substance". In other words, it is a sample of something in which all the molecules are lined up perfectly and there are no imperfections. I think it's easier to understand when you consider S=K_{b}lnW . Think about calculating degeneracy for a subs...

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Values of \Delta H of fusion and/or vaporization given in most problems and tables are written in terms of kJ/mol, so when you calculate the \Delta H of more than one mol, you must multiply it by the number of moles of the substance undergoing the phase change. Another way of thinking of this is tha...

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Problem 97 asks to calculate the Ka of HF given that 2(H+)(aq)+F2(g)+(2e-) \rightarrow 2HF(aq) has an E\circ =+3.03V. The solution manual uses the reverse equation and that of F2(g)+2e- \rightarrow 2F- to calculate Ecell and then the value of Ka. However, even though HF is used in the anode and the ...

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If you're referring to Gibbs Free Energy, $\Delta G$ is zero when the reaction is at equilibrium--this might be the boiling point I think.

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I think that the first thing to consider would be the state of the samples/compounds. This is the easiest thing to realize and is a major determinant of the sample's entropy. After that, if they're in the same state, I usually consider the size of the molecules and their polarities to try and get so...

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Hello, Problem 41 in chapter 8 involves 80g of ice at 0 degrees C being added to 400 g of water at 40C and asks what the final temperature is. I used the specific heat capacities of water and ice and the equation q=mCp(Tf-Ti) and set the qs equal to each other for the ice and the water, but I kept o...

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This question is based off of number 8f from the 2010 final in the course reader. The question involves the titration of 25.0mL of 0.10M acetic acid (CH3COOH) with .10M NaOH. Part F asks to calculate the pH at the stoichiometric point. In the solutions, it says that the pH is that of .050M NaCH3CO2....

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If Lewis acids are defined by their tendency to accept electron pairs, do they still lower a solutions's pH? How does the accepting of electrons increase the concentration of hydronium?

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Table J.1 in the Fundamentals section of the textbook lists common strong acids and bases. HCl, HClO3, and HClO4 are all listed as strong acids. Just out of curiosity, can Chlorine Dioxide form an acid? If so, why isn't HClO2 a strong acid like the other chlorates' acids are? Why does the number of ...

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Number 17.31a asks for the formula of potassium hexacyanidochromate(III). From my understanding, the roman numerals at the end of the name implied that the chromate ion had an oxidation state of 3+. This would mean that the [Cr(CN)6] part of the compound would have a net positive charge, and if it w...

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The first thing you need to consider is whether or not an octet exception is an option. In order to have more than an octet, the central atom needs to be a nonmetal in period three or later so that it has the empty d orbitals needed to expand its valence shell. Then you need to determine if the expa...

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In 59a, Chlorine has an unpaired electron but oxygen has a full octet. Since they are bonded, I think this means that oxygen is more electronegative than chlorine. I know that the electrons in Cl shield the valence electrons from the nucleus more, but its nuclear charge is higher; why is it less ele...

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I think I understand what you're asking, so I hope this helps. When we're given the change in radius, we double it because we dont know if we are increasing or decreasing. So if the radius was 5m (ridiculously large but it's just an example) and the change in radius were 1m, we would say delta x was...

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The equation E=hc/v pertains to the total energy of the photon. The way you are solving it (which is also the way I first tried to solve it), you are calculating the wavelength as if it only provided enough energy to emit the electron without it having any velocity (i.e. the threshold energy). You n...

CHEMISTRY COMMUNITY

Search found 19 matches

Re: Steric Strain

Re: Trans vs Cis stablity

Re: Naming—alphabetical order

Question 8 From This Year's Midterm

Re: reaction rate and rate constant

Re: Perfect Crystal

Re: ndeltaH(phase change) + MCdeltaT

Homework 14.97

Re: delta g = 0

Re: Which Has Higher Entropy?

Problem 8.41

Calculating pH at stoichiometric point for weak acids

Lewis Acids and pH

What makes an acid strong?

Writing Formulas from names

Re: Octet Exception

Chlorine and Oxygen

Re: Question about Heisenberg Equation

Re: What equation to use to find wavelength?