CHEMISTRY COMMUNITY

bridgetfoy_1D

What does primary/secondary amine mean? How do we identify which is which? Looking at the same problem as you (5A from 2013 midterm), how can we tell that that is a secondary amine?

bridgetfoy_1D

On the midterm question 2A, can someone please explain why q, w, and deltaH all = 0? I understand that deltaU=0 because it's isothermal, and I know that w=-q and deltaH=q so those must all be equal or equal to the negative. But I don't understand why they are all 0. Any help would be appreciated!

bridgetfoy_1D

On page 111 in the course reader, it says "bigger substituents have higher preference for equatorial position." This holds true for all complex molecules, so the chlorine and bromine substituents always prefer equatorial - it is always more stable if they are in this position versus axial.

bridgetfoy_1D

If we aren't told which reaction is reduced and which is oxidized and are given both Ecell values as positive, how do we know which equation to flip/switch the Ecell sign? Both reactions are initially written as reduction (with solids being formed).

bridgetfoy_1D

Dr. Lavelle, Thank you for your constant support, extra office hours and resources, and for doing everything you can to help us succeed. I truly felt like you wanted us to do well in your class, and that is very much appreciated especially in such a large student population. Thank you for selflessly...

bridgetfoy_1D

On page 3 of the OChem textbook at the bottom, how do you get the "-diene" at the end of the molecule 2-Methyl-1,3-butadiene? Also, I'm confused on how to start the numbering for this example. Which Carbon is 1, and what order/direction do you go from there?

bridgetfoy_1D

Is it acceptable to draw the line structures, or should we draw out the Lewis structures for the quiz? We have done a variety of both in class.

bridgetfoy_1D

Is there such thing as nucleophilic addition, or is it only electrophilic addition and nucleophilic substitution? Is the way to tell between the two whether or not the number of molecules goes from 2 to 1 (addition) versus 2 to 2 (substitution)? Is there any other way we should know to differentiate...

bridgetfoy_1D

Are the number of steps of a reaction always equal to the number of transition states? And is the number of intermediates always one less than the former? I'm noticing this trend, but want to make sure it's accurate for all curves (especially the first part). Thanks!

bridgetfoy_1D

I know that these three reactions are related through derivatives and their respective graphs and slopes, but is it to the extent that the second reaction graph is the derivative of the first reaction graph, and the derivative of that is the zero reaction graph? I was thinking these could correlate ...

bridgetfoy_1D

I am confused about when to use q=mCpdeltaT (where m=mass), q=nCpdeltaT (where n=number of moles), and q=CpdeltaT? These three equations are very similar yet are all used in different problems. I'm having a hard time figuring out when to use which equation. Any help would be appreciated!

bridgetfoy_1D

A calorimeter was calibrated with an electric heater, which supplied 22.5 kJ of energy as heat to the calorimeter and increased the temperature of the calorimeter and its water bath from 22.45 degrees Celsius to 23.97 degrees Celsius. What is the heat capacity of the calorimeter? How do you solve th...

bridgetfoy_1D

A problem from chapter 8 requires you to convert units L/atm to J using the "equivalency of the ideal gas constants" (taken from the answer book). I am not sure what that means or how to make this conversion.

bridgetfoy_1D

When naming a coordination compound, does the order of the formula matter? For instance, when writing the formula for triamminetrichloronickel(IV) sulfate, is there a difference (in science and in grading) between writing [NiCl 3 (NH 3 ) 3 ] 2 SO 4 (which is how the answer is written) and [(NH 3 ) 3...

bridgetfoy_1D

d orbital electrons are usually ejected before s orbital because their bond to the central atom is significantly weaker.

bridgetfoy_1D

The Henderson Hasselbalch equation could definitely be used for part A, especially since the concentrations of the conjugate acid and base are the same. These equal concentrations would cancel out the log[base/acid], therefore making it pKa=pH. As for part B, I think you must use the ICE table becau...

bridgetfoy_1D

A shift in equilibria means that either the reactant side or product side has too much substance and therefore more reaction will take place in order for the overall reaction to remain in a balanced equilibria (which means the amount chemically reacting from reactants to products is equal to the opp...

bridgetfoy_1D

In our course reader, ligand names are Fluoro for F-, Chloro for Cl-, Bromo for Br-, etc. However, in the textbook on page 742, they are fluorido, chlorido, bromido, etc. I am guessing that our course reader has the correct names that we will be tested on? I just want to make sure I'm learning the r...

bridgetfoy_1D

No, lone pairs on a molecule would prohibit it from being linear shape. Both AX2E1 and AX2E2 are bent because of the effect of the lone pairs.

bridgetfoy_1D

I am still slightly confused on what order to write electron configurations in. In my high school class, we were taught to write it just going across the periodic table so the numbers would be out of order. For instance, when writing the configuration for Tantalum (Ta), I was taught to write it like...

bridgetfoy_1D

Did you hear about the man who got cooled to absolute zero? Don't worry, he's 0K now.

Why did the acid go to the gym? To become a buffer solution.

yay for chemistry jokes!

bridgetfoy_1D

The molar mass of the metal hydroxide M(OH)subscript2 is 74.10 g/mol. What is the molar mass of the sulfide of this metal?

The solutions manual shows that the answer involves Calcium and CaS, but I don't know where the Calcium came from or how I am supposed to know to involve it in this problem.

bridgetfoy_1D

Do all electrons have the same minimum energy required to be emitted, or can various factors (heat, type of atom/molecule) affect the necessary energy for the electron's emission?

CHEMISTRY COMMUNITY

Search found 23 matches

Re: Final 2013 5A

Midterm question 2A

Re: How to determine higher stability

Flipping an Ecell equation

Re: Saying Thank You to Dr. Lavelle

Re: Naming [ENDORSED]

Drawing structures for Quiz 3

Electrophilic addition

Reaction steps and transition states

Zero, First, and Second Reactions

When to use which q= equation?

Homework question 8.23

Converting L/atm to Joules

Order of Naming Coordination Compound

Re: D orbital

Re: Chapter 13 Problem 3

Re: Shift in Equilibria

Naming Ligands

Re: Lone Pairs on Linear Molecule

writing electron configurations

Re: Post All Chemistry Jokes Here

Problem E15 from textbook

Electron Energy Emission