Search found 34 matches

by Josh_Zhong_1F
Fri Feb 17, 2017 10:51 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7567
Views: 1011119

Re: Post All Chemistry Jokes Here

Q: Why does hamburger yield lower energy than steak?
A: Because it's in the ground state.
by Josh_Zhong_1F
Sun Feb 12, 2017 10:21 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7567
Views: 1011119

Re: Post All Chemistry Jokes Here

Q: What do you do with a dead chemist?
A: Barium
by Josh_Zhong_1F
Thu Feb 09, 2017 4:57 pm
Forum: Balancing Redox Reactions
Topic: 14.5 Half Reactions
Replies: 4
Views: 482

Re: 14.5 Half Reactions

OHHHH..I think I understand what you mean Professor. Please correct me if I am wrong, O3 reacts with BrO3-; therefore, O3 is an oxidizing agent because O3 oxidation number is 0 while Br oxidation number is +5 Br- reacts with O2; therefore, Br- is a reducing agent because Br- oxidation number is -1 w...
by Josh_Zhong_1F
Thu Feb 09, 2017 4:51 pm
Forum: Balancing Redox Reactions
Topic: 14.5 Half Reactions
Replies: 4
Views: 482

Re: 14.5 Half Reactions

Hi,
But for this problem, the solution says that O3 is the oxidizing agent and Br- is the reducing agent.
I thought both O3 and Br- are oxidizing agent..

When both O3 and O2 have oxidation number "0", how do we determine whether it is oxidizing or reducing?


Thanks,
by Josh_Zhong_1F
Tue Feb 07, 2017 6:04 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7567
Views: 1011119

Re: Post All Chemistry Jokes Here

GOT MOLE PROBLEMS?
CALL AVOGADRO AT 602-1023

LOLOLOLOLLLLLLLLLL,
by Josh_Zhong_1F
Mon Jan 30, 2017 10:00 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Homework Problem 9.15(b)
Replies: 2
Views: 343

Homework Problem 9.15(b)

Hello,
I am wondering why the book use standard enthalpy of vaporization of 43.5kJ per mol instead of 40.7kJ per mol or 44.0 kJ per mol in homework problem 9.15(b)
by Josh_Zhong_1F
Mon Jan 30, 2017 6:19 pm
Forum: Administrative Questions and Class Announcements
Topic: Bruincast Audio Problem
Replies: 16
Views: 1597

Re: Bruincast Audio Problem

You need to download something called "silver light" , and sometimes is difficult to play.
Internet browser is better or apple's safari browser is fine too.
by Josh_Zhong_1F
Mon Jan 30, 2017 11:08 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7567
Views: 1011119

Re: Post All Chemistry Jokes Here

How about the chemical workers — are they unionized?
by Josh_Zhong_1F
Mon Jan 30, 2017 11:03 am
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: Book example problem 9.6
Replies: 2
Views: 381

Book example problem 9.6

Hi,
The book example on 9.6, I do not quite understand the cooling of acetone vapor from boiling to desired temperature, why does the equation use heat capacity Cp,m=4R ?

Thanks!
by Josh_Zhong_1F
Tue Jan 24, 2017 9:50 pm
Forum: Administrative Questions and Class Announcements
Topic: Bruincast Audio Problem
Replies: 16
Views: 1597

Re: Bruincast Audio Problem

Hi,

Thank you Professor.
I have contacted the technician, and bruincast is working great now!

Thanks,
by Josh_Zhong_1F
Mon Jan 16, 2017 7:48 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Error in the text book?
Replies: 1
Views: 222

Error in the text book?

Hi,
On page 293, Example problem 8.9, step 2 states that there is 4H2O2 in the reaction.
I cannot seem to figure out where is the 4H2O2 come from.
Would it be an error?

Thanks,
by Josh_Zhong_1F
Mon Jan 16, 2017 7:44 am
Forum: Administrative Questions and Class Announcements
Topic: Bruincast Audio Problem
Replies: 16
Views: 1597

Re: Bruincast Audio Problem

Yea, it happens in all three different lectures for every recorded sessions.
by Josh_Zhong_1F
Sun Jan 15, 2017 5:27 pm
Forum: Administrative Questions and Class Announcements
Topic: Bruincast Audio Problem
Replies: 16
Views: 1597

Bruincast Audio Problem

Hi Professor,
The Bruincast video and audio seem to have lacking of output. Many of the full sentences that were spoked were not recorded.
Just want to bring to your attention.

Thanks,
by Josh_Zhong_1F
Sun Dec 04, 2016 12:03 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7567
Views: 1011119

Re: Post All Chemistry Jokes Here

What Is The Chemical Formula For Coffee?

A. CoFe2



LOLOLOLLLL..
by Josh_Zhong_1F
Fri Dec 02, 2016 7:49 am
Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
Topic: 5 Percent Rule
Replies: 4
Views: 621

Re: 5 Percent Rule

I understand the fact that spending $100 is no different for a billionaire. But how does the 5% rule work in the context of solving x? How do we determine when to use the 5% rule? When do we use it????

Thanks,
by Josh_Zhong_1F
Sat Nov 26, 2016 5:12 pm
Forum: Amphoteric Compounds
Topic: Difference between Amphoteric and Amphiprotic
Replies: 2
Views: 1111

Difference between Amphoteric and Amphiprotic

Hi,
What is the difference between Amphoteric and Amphiprotic?
Also, what is the relationship between Amphiprotic and Autoprotolysis?

Thanks,
Josh
by Josh_Zhong_1F
Sat Nov 26, 2016 4:37 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7567
Views: 1011119

Re: Post All Chemistry Jokes Here

A proton, a neutron, and helium walk into a bar and order three beers. The bartender appears with 3 beers and asks the proton, “Are you sure you’re over 21?” The proton replies, “I’m positive.” So the bartender gives him the first beer. He gives the second beer to the neutron and says, “For you, no ...
by Josh_Zhong_1F
Fri Nov 18, 2016 1:17 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7567
Views: 1011119

Re: Post All Chemistry Jokes Here

First of all why do Chemistry graduates typically work in the Pharmaceutical industry, while Pharmacy graduates typically work in a Chemist shop? Anyway, the missus and I are both science graduates, Chemistry for her, and Physics and Computer Science for me. So typical conversations might be… I told...
by Josh_Zhong_1F
Sat Nov 12, 2016 2:59 pm
Forum: Naming
Topic: Negative charge. Add Ate to the end
Replies: 3
Views: 453

Re: Negative charge. Add Ate to the end

Hi,

How do you know the compound has a negative has a charge of -3?
by Josh_Zhong_1F
Sat Nov 12, 2016 2:57 pm
Forum: Naming
Topic: Naming Ligands
Replies: 2
Views: 357

Naming Ligands

Hi,

K3[CoF6], on the course reader, it is named: potassium-hexa-fluoro-cobaltate(III)

Why is it not: potassium-hexa-fluoro-cobalt(III)?
It does not have a negative charge in the complex...Don't we only add ate to complexes that have negative charge?


Thanks,
by Josh_Zhong_1F
Sat Nov 12, 2016 1:32 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Chapter 4 Problem 51
Replies: 1
Views: 252

Re: Chapter 4 Problem 51

Hi Emerald, I think the solution is written in a way just to show us the complete molecular orbitals when drawing the diagram for Li. I think it would be better to know the complete molecular orbital diagram and draw it out every time. Because you draw the diagram differently for Z<8 and Z>or = 8
by Josh_Zhong_1F
Wed Oct 12, 2016 7:07 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Clarification on ENERGY LEVEL concept
Replies: 3
Views: 1762

Clarification on ENERGY LEVEL concept

Hi, I have noticed that from the book(page 7 in chapter 1), atomic spectra calculation done by Rydberg could be written using the formula: v(frequency)=R[1/n1^2-1/n2^2]. However, in the course reader, we have done the example on page 48 using a different formula: Change of E=E(final)-E(initial) E(n)...
by Josh_Zhong_1F
Tue Oct 11, 2016 3:39 pm
Forum: Molarity, Solutions, Dilutions
Topic: Quiz 1 Fall 2015 #5 [ENDORSED]
Replies: 2
Views: 502

Re: Quiz 1 Fall 2015 #5 [ENDORSED]

YOU ARE AMAZING!
by Josh_Zhong_1F
Tue Oct 11, 2016 1:51 pm
Forum: Molarity, Solutions, Dilutions
Topic: Quiz 1 Fall 2015 #5 [ENDORSED]
Replies: 2
Views: 502

Quiz 1 Fall 2015 #5 [ENDORSED]

6.40 g of a compound was burned in air and produced 8.80 g of CO2 and 7.20 g of H20. Find the empirical formula of the compound.


I do not know how to approach this kind of problems.
Thanks!
by Josh_Zhong_1F
Tue Oct 11, 2016 1:48 pm
Forum: Balancing Chemical Reactions
Topic: Quiz 1 Prep Fall 2015
Replies: 2
Views: 531

Quiz 1 Prep Fall 2015

Aluminum and hydrogen chloride, HCI, react to form aluminum chloride in solution, AlCl3, and hydrogen gas. Balanced equation: 2Al + 6HCl -------> 2AlCl3 + 3H2 Question: If you had 5.43 g of aluminum and 7.80 g of hydrogen chloride, how many grams of AlCl3 would you get? I could not figure out where ...
by Josh_Zhong_1F
Tue Oct 11, 2016 1:31 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: quiz 1 fall 2014 prep #10
Replies: 4
Views: 653

Re: quiz 1 fall 2014 prep #10

Hi,

Where does the number -2.178x10^-18J come from??
by Josh_Zhong_1F
Tue Oct 11, 2016 1:16 pm
Forum: Balancing Chemical Reactions
Topic: Naming Chemical Formula and Balancing Chemical Equations [ENDORSED]
Replies: 5
Views: 1184

Re: Naming Chemical Formula and Balancing Chemical Equations [ENDORSED]

Hi Michelle,
How do you know that nitrogen and oxygen are N2 and O2, which is in gas state?
by Josh_Zhong_1F
Tue Oct 11, 2016 1:08 pm
Forum: Molarity, Solutions, Dilutions
Topic: Quiz 1 Prep
Replies: 2
Views: 363

Re: Quiz 1 Prep

THANK YOU!
by Josh_Zhong_1F
Tue Oct 11, 2016 7:50 am
Forum: Molarity, Solutions, Dilutions
Topic: Quiz 1 Prep
Replies: 2
Views: 363

Quiz 1 Prep

Hard Water is water that has high mineral content, mainly calcium ions(Ca2+) and magnesium ions(Mg2+). A concentration above 5.30x10^-3 is considered to be very hard water. Assuming that there are no magnesium ions present, is a 0.400 L solution of 0.120 g CaCO3 and 0.155 g CaSO4 very hard water? To...
by Josh_Zhong_1F
Tue Oct 11, 2016 7:43 am
Forum: Photoelectric Effect
Topic: Quiz 1 Prep [ENDORSED]
Replies: 1
Views: 449

Quiz 1 Prep [ENDORSED]

The work function for lithium is 4.6x10^-19 J 1) Calculate the lowest frequency of light that will cause photoelectric emission. 2) What is the maximum energy of the electrons emitted when light of 7.3x10^14 Hz is used? 1) When it asks for lowest frequency, I look at it as it means longest wavelengt...
by Josh_Zhong_1F
Thu Oct 06, 2016 7:56 pm
Forum: Balancing Chemical Reactions
Topic: Naming Chemical Formula and Balancing Chemical Equations [ENDORSED]
Replies: 5
Views: 1184

Naming Chemical Formula and Balancing Chemical Equations [ENDORSED]

Question:
When nitrogen and oxygen react in the cylinder of an automobile engine, nitric oxide, NO, is formed. Write a balanced equation for this reaction.

Comment:
I do not know how to write this formula out and then balance it. Nitrogen and oxygen both have negative charge. Please advise..

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