CHEMISTRY COMMUNITY

Tiffany Chen 2E

Generally, nucleophiles will also have lone pairs or double bonds as electron-rich regions. Electrophiles, on the other hand, will have open valences or be missing an electron, as they are electron-deficient.

Tiffany Chen 2E

The n in the Nernst equation stands for the transfer of electrons that were used in both balanced half-reactions of the anode and cathode. For #3B of the 2011 Final, the balanced half-reaction of the anode is 4OH - + MnO 2 → MnO 4 2- + 2H 2 O + 2e - while the balanced half-reaction of the cathode co...

Tiffany Chen 2E

Ethers and halogens are not given priority as functional groups when numbering; however, alcohols still do have priority.

Tiffany Chen 2E

If a cycloalkene was a substituent off a parent chain, what would the name of the cycloalkene end in? For example, if cyclopentane becomes cyclopentyl as a substituent, would it become cyclopentenyl as a double-bonded substituent?

Tiffany Chen 2E

To my understanding, the number of intermediates refers to the actual number of intermediate molecules that are produced by the end of the first transition state. The amount of valleys only indicates the period where intermediates have been created.

Tiffany Chen 2E

On page 17 of the Intro to Organic Chemistry textbook, how do you distinguish between the (E)-3,7-Dimethylocta-1,3,7-triene and (Z)-3,7-Dimethylocta-1,3,7-triene isomers? I'm thinking you start comparing at the 3 C double bond but don't know what to do beyond that? Thanks!

Tiffany Chen 2E

Which carbon the substituent is coming off of is denoted by the number in front of the substituent in the IUPAC name. Which direction you start counting from to place the substituent doesn't matter so much when you are drawing the structure given the IUPAC name.

Tiffany Chen 2E

Could someone also clarify what exactly a pseudo rate law is and what it is used for? Thanks!

Tiffany Chen 2E

Energetically favorable reactions tend to have a negative ΔG because they decrease free energy. Being energetically favorable means the reaction releases energy and produces heat.

Tiffany Chen 2E

Generally, a negative E° means the reaction is unfavorable. This is because in the equation ∆G°(redox)= -nFE°, a negative E° would yield a positive ∆G°. When ∆G° is positive, that means the reaction is not spontaneous and thereby unfavorable.

Tiffany Chen 2E

Generally, atoms, ions, and molecules that have electron affinity tend to make strong oxidizing agents, such as non-metals. For example, F 2 is the strongest common oxidizing agent. Metals, on the other hand, lose electrons readily and are good reducing agents. In addition, the strengths of oxidizin...

Tiffany Chen 2E

The Nitrogen is disregarded because N2 is an example of a gas in its standard state, which means that its standard enthalpy of formation is 0. Other gases in standard state and with a ΔHf of 0 include O2, F2, Br2, H2, and Cl2.

Tiffany Chen 2E

Molecules with hydrogen bonding usually have higher molar heat capacities. Substances with strong hydrogen bonds, such as water or ammonia, take the absorbed thermal energy and store it as potential energy within the hydrogen bonds. Thus, it takes more energy to increase the kinetic energy (or incre...

Tiffany Chen 2E

Enthalpy is the amount of heat released or absorbed in a thermodynamic system, or in other words, a change in energy in the form of heat. Internal energy, however, is the total amount of energy stored within a system, which involves both heat transferred to and work done by the system.

Tiffany Chen 2E

If you look at KBr, it gives off neither H+ ions nor OH- ions, because K+ does not act as an acid and Br- is a neutral conjugate base, causing KBr overall to be neutral.

Tiffany Chen 2E

You can disregard x when K<10^-4.

Tiffany Chen 2E

One way would be if you are given the K value. If K is a large value or K>1 you can assume that the reaction favors the products since the products constitute the numerator in the K expression (a larger numerator compared to the denominator would mean a larger K value), and thus the reactants would ...

Tiffany Chen 2E

An increase in temperature will cause an endothermic reaction to shift right and favor the product. This would create more product to make for a greater numerator in the equilibrium constant, thus, increasing the equilibrium constant. Likewise, in a forward exothermic reaction, increasing the temper...

Tiffany Chen 2E

Yes, ligands are only applicable to transition metals. A bond between a nonmetal and a metal is an ionic bond, while a bond between nonmetals is covalent.

Tiffany Chen 2E

Are there any distinguishing characteristics of coordinate covalent bonds, aside from being a bond between a transition metal and ligand? For example, are they stronger or more stable than other types of bonds?

Tiffany Chen 2E

If there is only one lone pair, the molecule should be polar. The lone pair creates asymmetry within the molecule's shape because it is more localized than bonding electrons, creating an uneven distribution of electrons and subsequently changing the overall molecular dipole moment.

Tiffany Chen 2E

I believe quadruple bonds are possible; however, they usually require the elements to be in the d-orbital to form, such as transition metals.

Tiffany Chen 2E

I was told only to use the equation E{n}=-\frac{hR}{n^2} . However, you can use the simplified form as long as you show how you derived it from the original equation. You should use the simplified form if you are confident in your calculations, otherwise I would suggest using the original E{n}=-\fra...

Tiffany Chen 2E

Yes, you should use as many sig figs as are in the constants you use.

Tiffany Chen 2E

Personally, for a problem like this, I would actually rearrange the equation c=λv into v=c/λ and then plug the rearranged equation into E=hv for v in order to avoid any rounding errors. However, if you were to do it with multiple steps, my TA actually told me to round the first answer at least 2 sig...

Tiffany Chen 2E

Someone elaborate or correct me if I am wrong, but I believe the 4pi has to do with the ways one can express frequency. This equation specifically involves the number of cycles per second (as in Hz) but can also be considered as the number of radians covered per second so the 4pi must be involved in...

CHEMISTRY COMMUNITY

Search found 26 matches

Re: General Question about Nucleophiles vs. Electrophiles

Re: N in Nernst Equation

Re: priority for naming

Cycloalkenes as Substituents

Re: Intermediates

Geometric Isomers

Re: Structures and Substituents

Re: Pseudo rate laws

Re: Energetically Favorable

Re: Redox reactions

Re: Reducing and oxidizing agents

Re: Homework problem 8.59

Re: molar heat capacity

Re: Enthalpy and internal energy

Re: Determining pH of aqueous KBr

Re: Disregarding the X?

Re: How to find if you -x or +x for ICE

Re: Effects on Equilibrium constants

Re: Ligand Definition

Re: Ligands and Transition Metal Bonding

Re: polarity question

Re: Bonds

Re: Rydberg Formula Derivation and Units for Quiz #1

Re: Sig figs when problem only gives you "n" values [ENDORSED]

Re: How often to round sf in multi-step calculations

Re: Heisenberg Indeterminacy Equation