Search found 23 matches

by Davalanya 1F
Sun Jul 30, 2017 9:58 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 11.45 Part C
Replies: 3
Views: 284

Re: 11.45 Part C

Also, you may want to check your calculations because it's supposed to be Cl2 = 8.2*10^4 and F2= 3.2*10^4. Additionally based on these results it is seen that Cl2 has the largest number making it more stable.
by Davalanya 1F
Sun Jul 30, 2017 9:56 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 11.45 Part C
Replies: 3
Views: 284

Re: 11.45 Part C

Fluorine is small and has more lone pairs than Cl. Eventhough fluorine may have a high electronegativity, it loses its electrons a lot easier than Cl due to being an almost completed octet.
by Davalanya 1F
Sun Jul 30, 2017 9:43 pm
Forum: Bronsted Acids & Bases
Topic: Tips on studying
Replies: 3
Views: 321

Re: Tips on studying

I also find the practice old midterms and tests in the course reader to be helpful because it shows how Lavelle has phrased questions about certain topics in the past.
by Davalanya 1F
Sun Jul 30, 2017 9:02 pm
Forum: Identifying Acidic & Basic Salts
Topic: Page 159 course reader
Replies: 1
Views: 328

Re: Page 159 course reader

I think it has to do with the sentence before it, " cations from groups 1 and 2 do not affect ph" and Na is in group 1 and can not generate the [H30+] and [H30+] needs to be there for the ph to calculated.
by Davalanya 1F
Tue Jul 25, 2017 12:19 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: 11.33
Replies: 4
Views: 479

Re: 11.33

oh, that answer was just for the first part but you do calculate Q and K the same.
by Davalanya 1F
Mon Jul 24, 2017 8:20 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: 11.33
Replies: 4
Views: 479

Re: 11.33

Its because of the units. it mmoles not moles. you have to do the conversion
by Davalanya 1F
Mon Jul 24, 2017 8:02 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Self Test 2
Replies: 2
Views: 377

Re: Self Test 2

I have a question regarding how you solved for 8 and 6. Could you explain the steps for those? Also how were you able to determine number of attachments for the compounds?
by Davalanya 1F
Sun Jul 16, 2017 4:35 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: How to display polar dipole moments in VSEPR model
Replies: 2
Views: 362

Re: How to display polar dipole moments in VSEPR model

The arrows show the direction of the dipole moments. If it's nonpolar the dipole moments cancel, you can think of it as the electron replusion, if there's repulsion it's polar and if there's attraction it's nonpolar because it cancels out the dipole moment. You can draw it to double check.
by Davalanya 1F
Sun Jul 16, 2017 4:30 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Quick Question about SO4
Replies: 8
Views: 713

Re: Quick Question about SO4

Isn't the most stable structure an average of them all?

I know that you can't calculate a formal charge of a molecule because you need to add them all up to see what the total formal charge is. You calculate it by element.
by Davalanya 1F
Sun Jul 16, 2017 4:08 pm
Forum: Quantum Numbers and The H-Atom
Topic: Writing e- configurations of atoms
Replies: 2
Views: 286

Re: Writing e- configurations of atoms

Cu and Cr are just the two e- configuration exceptions we have to know. They do not follow the normal guide of the periodic table. if you look at the e- configuration of zinc its 3d^10s^2. In the chemical principles book, when you open the textbook the periodic table has the e- configurations for al...
by Davalanya 1F
Sun Jul 16, 2017 3:56 pm
Forum: Lewis Structures
Topic: Seesaw Structure question
Replies: 3
Views: 581

Re: Seesaw Structure question

What I understand about the VSEPR model is that it always you to take into consideration the lone pairs. Lone pairs on the Lewis structure cause the shape to change. It's not a simple move as placing the electron on top, the structures take into account the repulsion and polarity of the molecule. I ...
by Davalanya 1F
Sun Jul 09, 2017 5:52 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Formal Charge
Replies: 3
Views: 375

Re: Formal Charge

I think in order to calculate formal charge you have to first draw our the Lewis structure so that you can see the lone pairs and the bonds.
by Davalanya 1F
Sun Jul 09, 2017 5:45 pm
Forum: DeBroglie Equation
Topic: Should velocity always be in m.s. when solving? [ENDORSED]
Replies: 11
Views: 828

Re: Should velocity always be in m.s. when solving? [ENDORSED]

In past problems, I want to say that you have to change the units because it is commonly in m*s.
by Davalanya 1F
Sun Jul 09, 2017 5:42 pm
Forum: Photoelectric Effect
Topic: Energy in kj or j when solving a problem?
Replies: 10
Views: 573

Re: Energy in kj or j when solving a problem?

I think it has to be changed to Joules always because when we cancel units for energy we are left with J, and if we leave it in kj we have to change the rest of the other units to get the kj in the final answer.
by Davalanya 1F
Tue Jul 04, 2017 8:12 pm
Forum: Student Social/Study Group
Topic: Self Test 1 Answers
Replies: 8
Views: 807

Re: Self Test 1 Answers

5. is C3HO4

I checked with an old post from Lavelle.
viewtopic.php?t=2309
by Davalanya 1F
Tue Jul 04, 2017 5:23 pm
Forum: Student Social/Study Group
Topic: Self Test 1 Answers
Replies: 8
Views: 807

Re: Self Test 1 Answers

Could you explain how you set up 1B? I think I'm overthinking the entire thing. Thanks!
by Davalanya 1F
Mon Jul 03, 2017 12:10 am
Forum: Molarity, Solutions, Dilutions
Topic: E.1 Homework Problem
Replies: 2
Views: 274

Re: E.1 Homework Problem

viewtopic.php?f=8&t=21190&p=60614&sid=030e415c9032b9f8c8cfebe288630dfe#p60614

You use the 144 pm to times it by 2 which is because of the fact that the diameter is which the radius. After you convert it to the right units and etc.
by Davalanya 1F
Mon Jul 03, 2017 12:09 am
Forum: SI Units, Unit Conversions
Topic: Exercise E1 [ENDORSED]
Replies: 6
Views: 774

Re: Exercise E1 [ENDORSED]

In order to get diameter, you have to times the radius by 2 because its twice the radius. that's where the 2 came from
by Davalanya 1F
Mon Jul 03, 2017 12:01 am
Forum: Student Social/Study Group
Topic: Study Group for Summer 17
Replies: 2
Views: 303

Re: Study Group for Summer 17

I think on campus would be best, I don't live in the dorms currently. Im free most of the time expect for Monday-Wednesday at 1-3pm.
by Davalanya 1F
Sun Jul 02, 2017 9:53 pm
Forum: Significant Figures
Topic: Mantissa
Replies: 1
Views: 286

Re: Mantissa

I believe that it is the number before the x 10^(insert a number). So simply for example 2.5 would be the mantissa in the answer 2.5 *10^5.
by Davalanya 1F
Sun Jul 02, 2017 9:49 pm
Forum: Student Social/Study Group
Topic: Study Group for Summer 17
Replies: 2
Views: 303

Study Group for Summer 17

Hey, guys I was wondering if anyone wants to make a study group for this summer?
if so contact me!
Email: davalanyahernandez@gmail.com
by Davalanya 1F
Wed Jun 28, 2017 3:53 pm
Forum: Properties of Light
Topic: When using the constant C
Replies: 2
Views: 260

When using the constant C

i know today in lecture that Professor Lavelle defined c as 3.00*10^8 however in the book its 2.99* 10^8 and I was wondering if this mattered during tests if we used either one of them.
by Davalanya 1F
Mon Jun 26, 2017 6:06 pm
Forum: SI Units, Unit Conversions
Topic: Exercise E1 [ENDORSED]
Replies: 6
Views: 774

Re: Exercise E1 [ENDORSED]

I believe that you have to change the units of 144 pm to meters first, then times it by 2. Using that answer you have to times it by 1.0 mole (6.0221*10^23) and finally, remember to convert your meters to kilometers.

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