CHEMISTRY COMMUNITY

Miya McLaughlin 2B

Yes, it will take more energy for the slow step to be carried out compared the fast step because there is a higher energy barrier that the atoms must overcome. (ie higher activation energy) A higher activation energy means not as many molecules will be able to get over the energy barrier as often. S...

Miya McLaughlin 2B

A concentration cell is when a galvanic or voltaic cell is made using the same components but at different concentrations. For example, one side of the cell could have Cu + ions with a concentration of 0.1 M while the other side has a concentration of 1 M. Because both sides have Cu+ ions, both the ...

Miya McLaughlin 2B

No, those prefixes don't count when putting them in alphabetical order. (Example: Etheyl would be listed before dimethyl)

Miya McLaughlin 2B

The name will tell you where the substituent is located. In the name, the number before the substituent will indicate which carbon it is attached to. If you are instead given a picture, the substituent will be the line or series of lines protruding from one of the carbons in the chain. If you are as...

Miya McLaughlin 2B

The arrow doesn't necessarily mean a bond is being broken, it just indicates where the electrons are coming from and where they end up. It's just easy for the electrons to come from bonds because they are more exposed than the electrons within the shells, thus they are easier to remove. The explanat...

Miya McLaughlin 2B

The homework problems are listed at the end of each chapter in the organic chem textbook. They are pretty hard to find because the entire book is black and white, which makes all the pages look the same. The problems for Thermodynamics and organic chem are right after chapter 4. There should be a pa...

Miya McLaughlin 2B

An intermediate is any substance that is created in one step(product) then used up in another. If you were to add the step reactions together the intermediates would cancel out. Here is a visual example from the text book. Step 1 AC + B --> AB + C Step 2 AC + AB --> A 2 B +C In the first step, AB is...

Miya McLaughlin 2B

Yes. When you add the equations together, all the intermediates should cancel out. Intermediates won't be in the final equation that represents the overall reaction.

Miya McLaughlin 2B

You would need to use the half reaction that looks like this: Fe 3+ + e - --> Fe 2+ This is the only half reaction in which Fe is an ion on both sides. The other ones include Fe(s) in it's solid form. In the question, iron(II) chloride is your only source of iron and it can only give off Fe ions, no...

Miya McLaughlin 2B

I made a mistake when writing ln. [Cl^-] should be squared.

ln( [H⁺]² [Cl^-]² / [H₂] )

Miya McLaughlin 2B

It's helpful to look at the nernst equation like this: E cell = E - (RT/nF) ln([P]/[R]) Here is an example, from the homework: H 2 (g) + Hg 2 Cl 2 (s) --> 2H + (aq) + 2Cl - (aq) For this equation, the value you'd be taking the ln of would look like this ln( [H + ] 2 [Cl - ] / [H 2 ] ) To find the pH...

Miya McLaughlin 2B

The 0.0592 comes from combining all the constants in the equations. It represents RT/F, which is the gas constant multiplied by the temperature (in this case it's the standard temp of 273 K), then it is divided by one Faraday(F) which is 96485 C/mol. The n remains a variable because it depends on th...

Miya McLaughlin 2B

In problem 14.27 of the homework it asks you to calculate the standard potential for the half reaction: U 4+ (aq) + 4e - --> U(s) I tried adding the two half reactions from Appendix 2B that also included U to get this equation. Then I added together the E values of each equation and ended with E=-2....

Miya McLaughlin 2B

The delta H values given in the problem are the reaction enthalpies for combustion(enthalpy of combustion is denoted by a little c subscript). You can write the three combustion reactions for each compound and use those equations for Hess' Law. For a combustion reaction, an organic compound reacts w...

Miya McLaughlin 2B

The subscript "c" on the delta H denotes that it's the Standard Enthalpy value for a combustion reaction. A combustion reaction is when a compound burns completely with O2 gas to create CO2 and H2O. Here is an example. Ex: 2 C2H2(g) + 5 O2(g) --> 4 CO2(g) + 2 H2O(g) It's not the exact oppo...

Miya McLaughlin 2B

Extensive Properties are physical properties that depend on the size of the sample you are using. Intensive Properties are physical properties that DO NOT depend on the size of the sample. Example: Say you have a sample of water. The volume(a physical property) of that sample will be dependent on ho...

Miya McLaughlin 2B

For this problem, it asks if a set of equations can be classified as reactions between Bronsted acids and bases. I know that means a proton must be transferred from one molecule to another. However, with the reactions they gave us, I don't know how to tell if a proton is transferred in that way? The...

Miya McLaughlin 2B

The anti-bonding orbitals have a higher energy because they are less stable than the bonding orbitals. This is because they are farther away from the nuclei of the atoms. Stability = lower energy. This higher energy level, means anti-bonding orbitals are closer in energy to the less electronegative ...

Miya McLaughlin 2B

Heisenberg is driving down the road when a cop pulls him over and asks him, "Do you know how fast you were going back there?"
To which Heisenberg responds, "No, but I know where I was."

Miya McLaughlin 2B

The bond angles for a see-saw shape are 90 degrees, 180 degrees and 120 degrees. T-shaped is 90 and 180. Square-pyramidal is 90. Square planar is also 90. A good way to figure out the bond angles is to look first look at how many regions of electron density there are. Take the see-saw shape for exam...

Miya McLaughlin 2B

For this problem in the text book, it asks you to select the Lewis structure that is "likely to make the dominant contribution to a resonance hybrid."

What does it mean by "resonance hybrid" and how do you determine if it makes a contribution?

Miya McLaughlin 2B

This makes a lot more sense! Thank you so much for your help. I understand now how to solve for the separate elements.

Miya McLaughlin 2B

In the workbook, there is a quiz prep question that reads, "6.40 g of a compound was burned in air and produced 8.80 g of CO2 and 7.20 g of H2O. Find the empirical formula of the compound." I understand how to solve these problems when the mass of each element is given separately(i.e. 6.0 ...

Miya McLaughlin 2B

I believe "principal quantum number" is referring to the energy levels; n=1, 2, . . . etc. According to the textbook, each of the series(Balmer, Lyman, etc.) correspond to a certain final value of n. For example, when an electron jumps down from n=3 to n=2, the line of radiation given off ...

CHEMISTRY COMMUNITY

Search found 24 matches

Re: Two Step Reactions

Re: Cell potential equals zero?

Re: Arranging substituents while naming

Re: Number in front of name

Re: Determining Where Hydrogen Bonds

Re: Chapter 4 of the book

Re: intermediate

Re: Confusion about intermediates

Re: 14.17 (HW problem)

Re: Calculating pH

Re: Calculating pH

Re: Nernst Equation [ENDORSED]

Calculating the Potential of Half Reactions

Re: Number 57 in Chapter 8 Homework

Re: What does a Standard Enthalpy with a subscript "c" mean?

Re: Measuring Heat Transfer (extensive vs intensive)

Homework 12.9 [ENDORSED]

Re: Molecular Orbitals between Two Atoms that are Different Elements

Re: Post All Chemistry Jokes Here

Re: bond angles

Homework 3.71 [ENDORSED]

Re: Empirical Formulas from Compounds [ENDORSED]

Empirical Formulas from Compounds [ENDORSED]

Re: Question 1.11