## Search found 16 matches

Sat Mar 18, 2017 11:11 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8252
Views: 1444692

### Re: Post All Chemistry Jokes Here

I would like to apologize for not adding more jokes, but I only post them periodically
Sun Mar 05, 2017 3:48 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8252
Views: 1444692

### Re: Post All Chemistry Jokes Here

Wed Feb 22, 2017 4:32 pm
Forum: General Rate Laws
Topic: Self-Test 15.2A
Replies: 1
Views: 321

### Self-Test 15.2A

The average rate of the reaction N2(g) + 3 H2(g) --> 2 NH3(g) over a certain period is reported as 1.15 (mmol NH3)*L -1 *h -1 . (a) What is the average rate over the same period in terms of the consumption of H2? (b) What is the unique average rate? For part (a), I am unsure of how to go about solvi...
Sat Feb 11, 2017 3:25 pm
Forum: Balancing Redox Reactions
Topic: Self-Test 14.1A [ENDORSED]
Replies: 1
Views: 318

### Self-Test 14.1A[ENDORSED]

Question: Copper reacts with dilute nitric acid to form copper (II) nitrate and the gas nitric oxide, NO. Write the net ionic equation for the reaction. I would just like to clarify if this is the correct skeletal equation to go about solving the problem: Cu(s) + HNO_{3} (aq) --> Cu^...
Thu Feb 02, 2017 2:04 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Self-Test 9.15A
Replies: 1
Views: 314

### Self-Test 9.15A

Calculate the entropy change of the surroundings when 1.00 mol H2O(l) vaporizes at 90°C and 1 bar. Take the enthalpy of vaporization of water as
40.7 kJ*mol-1.

For this problem, you do not need to set the 40.7 kJ*mol-1 negative because it is already given at the vaporization stage correct?
Wed Jan 25, 2017 6:34 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Quiz 1 Prep #5
Replies: 5
Views: 1691

### Re: Quiz 1 Prep #5

As mentioned above, it is probably a typo as without the coefficient of 2 NH3, the chemical equation itself would be unbalanced.
Sat Jan 14, 2017 2:38 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Question about using mean bond enthalpies to estimate the enthalpy of a reaction
Replies: 1
Views: 252

### Question about using mean bond enthalpies to estimate the enthalpy of a reaction

One of the textbook questions list the following: Use bond enthalpies to estimate the standard enthalphy of the reaction... CCl 3 CHCl 2 (g) + 2 HF (g) ---> CCl 3 CHF 2 (g) + 2 HCl (g) The answer the the question is -24 kJ/mol, but when I try and calculate it on my own I keep getting -30 kJ/mol. I w...
Sat Dec 03, 2016 7:16 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: D-block exceptions for midterm and f-block
Replies: 4
Views: 813

### Re: D-block exceptions for midterm and f-block

Thank you for posting this, saved me quite a bit of studying.
Sun Nov 27, 2016 11:07 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8252
Views: 1444692

### Re: Post All Chemistry Jokes Here

I asked the guy sitting next to me if he had any Sodium Hypobromite…
He said NaBrO
Wed Nov 16, 2016 10:52 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Correct way to write molecular configuration?
Replies: 1
Views: 284

### Correct way to write molecular configuration?

Do we need to specify the specific p-states? For example, for C 2 , is the correct configuration: 1. (\sigma 2s)^2(\sigma* 2s)^2(\sigma 2pz)^2(\pi 2px)^1(\pi 2py)^1 or 2. (\sigma 2s)^2(\sigma* 2s)^2(\sigma 2pz)^2(\pi 2p)^2 Basic...
Sun Nov 13, 2016 9:51 am
Forum: Biological Examples
Topic: Fe and proteins
Replies: 6
Views: 798

### Re: Fe and proteins

thank you for clearing this up, had some difficulty in this as well
Mon Nov 07, 2016 8:48 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8252
Views: 1444692

### Re: Post All Chemistry Jokes Here

Why was there a warrant out for Sodium?

It was wanted for assault (a salt)
Sat Nov 05, 2016 7:55 pm
Forum: Administrative Questions and Class Announcements
Topic: Bruincast
Replies: 26
Views: 8809

### Re: Bruincast

As mentioned above, just download the lectures onto your Desktop and then you can set the playback speed on a video player such as QuickTime for Mac
Sun Oct 30, 2016 6:41 pm
Forum: Trends in The Periodic Table
Topic: Quiz 2 Typo?
Replies: 3
Views: 587

### Re: Quiz 2 Typo?

So it wasn't just me that was thinking that haha nice
Sun Oct 16, 2016 3:31 pm
Forum: Properties of Light
Topic: HW Question Ch #27 [ENDORSED]
Replies: 5
Views: 1119

### Re: HW Question Ch #27[ENDORSED]

I had a similar question, but I am still confused about how it is 6.022X10^23 photons per mole. Is it just a known constant that just like atoms there are a certain number of photons per mole? 6.022x10^23 is a constant that can be expressed as per mole of anything. As stated above, it can represent...
Thu Sep 29, 2016 10:17 am
Forum: Balancing Chemical Reactions
Topic: Balancing Chem Eq Audio Visual Post-Assess #8
Replies: 2
Views: 455

### Re: Balancing Chem Eq Audio Visual Post-Assess #8

To calculate the net number of moles of gas produced, you take the difference of the sum of the coefficients of the reactant by the sum of the coefficients of the product. Here is an illustrated format of how you would calculate it: Sum of Coefficients of the Product - Sum of Coefficients of the Rea...