Search found 12 matches

by Evamae Bayudan 1B
Fri Dec 12, 2014 11:29 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Endothermic or Exothermic?
Replies: 4
Views: 560

Endothermic or Exothermic?

I understand that increasing the temperature of an endothermic reaction shifts the reaction to towards the products, but how do we know if the reaction is endothermic or exothermic without it being directly stated in the problem or without being told the ΔH°.
by Evamae Bayudan 1B
Thu Nov 27, 2014 4:08 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Problem 10.77 in textbook
Replies: 2
Views: 381

Re: Problem 10.77 in textbook

Yeah, I know the answers would be the same; I just thought Lavelle could put it on the "Solution Manuel Errors" list in case others encounter it, too.
by Evamae Bayudan 1B
Wed Nov 26, 2014 10:25 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Problem 10.77 in textbook
Replies: 2
Views: 381

Problem 10.77 in textbook

The problem says to consider the equilibrium 3NH3(g) +5O2(g) <--> 4NO(g) + 6H2O (g). I thought the equation has to balanced in order for it to be in equilibrium. The reactant side has 3 Nitrogens and 9 Hydrogens while the product side has 4 Nitrogens and 12 Hydrogens. Shouldn't the 3 coefficient for...
by Evamae Bayudan 1B
Tue Nov 18, 2014 7:23 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 912351

Re: Chemistry Jokes

Here are some more jokes!

Q: Why do chemists like nitrates so much?
A: They're cheaper than day rates.

Q: What is the show cesium and iodine love watching together?
A: CSI
by Evamae Bayudan 1B
Tue Nov 11, 2014 1:42 pm
Forum: Electronegativity
Topic: Electronegativity of Nitrogen and Sulfur
Replies: 3
Views: 4727

Re: Electronegativity of Nitrogen and Sulfur

Nitrogen is more electronegative than sulfur because it's electronegativity is 3.0 while sulfur's electronegativity is 2.6. There is a chart on the top of page 78 in the textbook if you want to look at the trends of the other elements.

Hope this helps!
by Evamae Bayudan 1B
Sat Nov 08, 2014 8:54 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Antibonding pairs
Replies: 5
Views: 521

Re: Antibonding pairs

Antibonding pairs result in the raising of energy, which causes destabilization. The more antibonding pairs there are, the more likely it is unstable. Antibonding pairs also decrease the bond order of compounds, which in turn decreases the bond strength and increases the bond length.
by Evamae Bayudan 1B
Sun Nov 02, 2014 9:22 pm
Forum: Octet Exceptions
Topic: Radicals and Biradicals
Replies: 1
Views: 348

Re: Radicals and Biradicals

Radicals play an important role in our lives. Foods become rancid and plastics degenerate in sunlight all because of radicals. Aging is also caused by radicals. Antioxidants can react with radicals to delay their damage. There is a section called "Radicals and Biradicals" in the textbook o...
by Evamae Bayudan 1B
Sat Nov 01, 2014 10:17 am
Forum: Bond Lengths & Energies
Topic: Bond lengths and dissociation energies?
Replies: 1
Views: 400

Bond lengths and dissociation energies?

There is a table and a chart on page 82 of the textbook stating the average bond lengths between atoms. Do we have memorize this chart for the quiz, midterm, or final? Also, do we have to memorize the dissociation energies for each bond on page 80?

Thank you
by Evamae Bayudan 1B
Sun Oct 26, 2014 1:22 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Exceptions to Electron Configurations
Replies: 4
Views: 2433

Re: Exceptions to Electron Configurations

The ground state electron configuration for Sn is [Kr]4d^10 5s^2 5p^2. Sn ^ 4+ has a +4 charge, so you would take away 4 electrons. You would remove the electrons 5s^2 and 5p^2 to gain the +4 charge, leaving you with [Kr]4d^10. In the textbook, it says "The d-electrons of the p-block atoms are ...
by Evamae Bayudan 1B
Sat Oct 18, 2014 8:29 pm
Forum: DeBroglie Equation
Topic: 1.27
Replies: 1
Views: 286

Re: 1.27

The mass of an electron is different from the mass of a neutron. The mass of an electron is 9.10938 × 10^-31kg while the mass of a neutron is 1.674927351×10^-27kg. Since problem 1.27 asks for the velocity of a neutron, you would use 1.674927351×10^-27kg as the mass.
by Evamae Bayudan 1B
Sat Oct 11, 2014 3:58 pm
Forum: Photoelectric Effect
Topic: If ∅ for Na is 150.6 kJ.mol-1, how do I get the mass of Na?
Replies: 1
Views: 459

Re: If ∅ for Na is 150.6 kJ.mol-1, how do I get the mass of

When you're doing k=1/2mv^2, the mass is the mass of the electron. The mass of an electron is a constant number, and it can be found on the back of our periodic table if you bought the course reader. The mass of an electron is 9.10938 x 10^-31kg
by Evamae Bayudan 1B
Sat Oct 11, 2014 1:27 pm
Forum: Significant Figures
Topic: All students read this sig fig post [ENDORSED]
Replies: 91
Views: 9099

Re: All students read this sig fig post [ENDORSED]

Will we be penalized for putting extra significant figures?

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