Search found 31 matches

by Alejandro Salazar 1D
Sun Jun 10, 2018 9:40 pm
Forum: Identifying Acidic & Basic Salts
Topic: strong acid/base?
Replies: 3
Views: 260

Re: strong acid/base?

Strong Bases are determined by the first two groups of elements(Alkali and Alkaline Earth Metals) paired with hydroxide ions (OH-)
by Alejandro Salazar 1D
Sun Jun 10, 2018 9:38 pm
Forum: Lewis Acids & Bases
Topic: Determining Acid Strength
Replies: 6
Views: 356

Re: Determining Acid Strength

I would recommend memorizing the 7 common strong acids, which are HCI, HBr, HI, HNO3, HCIO3, HCIO4, H2SO4
by Alejandro Salazar 1D
Sun Jun 10, 2018 9:34 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted vs Lewis Acids and Bases
Replies: 5
Views: 398

Re: Bronsted vs Lewis Acids and Bases

Arrhenius Acid is a compound that releases hydrogen ions in water Arrhenius Base is a compound that releases hydroxide ions in water Lewis Acid: is a species that ACCEPTS an electron pair Lewis Base is a species that DONATES an electron pair Bronsted acid is a proton donor and donates a hydrogen ion...
by Alejandro Salazar 1D
Sat Jun 02, 2018 2:43 pm
Forum: Biological Examples
Topic: Biological Function
Replies: 2
Views: 216

Biological Function

In class, it was discussed a few transition metals and their biological function. For example, Cr--> assist insulin in control of blood sugar. For Cobalt --> the Professor only mentioned something about B12. I'm wondering if someone was able to stay after class to ask about it? Just curious about th...
by Alejandro Salazar 1D
Sat Jun 02, 2018 2:34 pm
Forum: Biological Examples
Topic: Chemotherapy Example
Replies: 2
Views: 253

Re: Chemotherapy Example

Cis-diamine-dichloro-platinum (ll) is cis and not trans. Cis has the same two element on one side while trans has them on opposite sides. Nitrogen on DNA replaces the Cl on this cation. Although trans-diamine-dichloro-platinum (ll) has a chloride, cis diamine-dichloro plantinum(ll) has two on the sa...
by Alejandro Salazar 1D
Sat Jun 02, 2018 2:21 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Naming shape
Replies: 7
Views: 260

Re: Naming shape

I believe we will need to know both the electronic(lone pair present) shape and the molecular shape

Therefore, it is a good idea to be able to recognize the AXE formula
by Alejandro Salazar 1D
Sat May 26, 2018 4:21 pm
Forum: Bond Lengths & Energies
Topic: Bond Order
Replies: 4
Views: 250

Re: Bond Order

Bond order formula

BO: (1/2)(number of bonds-number of anti bonds)
by Alejandro Salazar 1D
Sat May 26, 2018 4:09 pm
Forum: Lewis Acids & Bases
Topic: Lewis acid vs. base
Replies: 5
Views: 195

Re: Lewis acid vs. base

Lewis Acids: molecule that accepts a pair of electrons from another atom 1. has an incomplete octet 2. has a double or triple bond 3. or, typically has a positive charge or neutral. H+ Lewis Bases: molecule that donates a pair of electron to another atom 1. has a lone pair 2. or typically has a nega...
by Alejandro Salazar 1D
Sat May 26, 2018 3:48 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar Bonds versus non polar bonds
Replies: 2
Views: 97

Polar Bonds versus non polar bonds

On Friday's lecture, the Professor included on the slides, "Polar molecules interact with an electrostatic potential created by cation or anion" I'm not sure what that mean.
I need help on how to determine that a molecule is polar or nonpolar like CCl4 and CHCl3. Thank you!
by Alejandro Salazar 1D
Sun May 20, 2018 8:57 pm
Forum: Electronegativity
Topic: In Class Example Between LiF and CsF
Replies: 2
Views: 299

Re: In Class Example Between LiF and CsF

Yeah, I agree it does not make sense when looking at the electronegativity difference. But, I think it has to do with what the professor had mentioned that this is only a "rough guideline"
by Alejandro Salazar 1D
Fri May 18, 2018 10:39 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Lewis Structure [ENDORSED]
Replies: 7
Views: 258

Re: Lewis Structure [ENDORSED]

I don't think it matters for lewis structures. But I believe it does matter once we start drawing out the shapes and structure of molecules.
by Alejandro Salazar 1D
Fri May 18, 2018 10:20 pm
Forum: Administrative Questions and Class Announcements
Topic: Absent Friday
Replies: 4
Views: 334

Re: Absent Friday

Today's lecture, Professor Lavelle went over Interactions between Ions and molecules Ion --> Ion Ion --> Dipole Dipole --> Dipole Dipole induced dipole On the image(from Google), there is electrostatic attraction between the molecule is attempting to become symmetry in the charge. The shape of the m...
by Alejandro Salazar 1D
Sun May 13, 2018 10:26 pm
Forum: Resonance Structures
Topic: Resonance Structure Problems
Replies: 3
Views: 146

Re: Resonance Structure Problems

I believe we have to draw at least one to demonstrate that we know this compound has a resonance structure and it does not matter which resonance structure
by Alejandro Salazar 1D
Fri May 11, 2018 8:14 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration-(Sn)
Replies: 5
Views: 254

Re: Electron Configuration-(Sn)

When writing this out just remember that it is written from the lower energy levels to highest so "p,s,d,f" and must be filled in that order. May you please explain this as the example above shows the order to be d, s and p. Thank you! I'm not sure if this helps. See attachment. You place...
by Alejandro Salazar 1D
Fri May 11, 2018 7:47 pm
Forum: Resonance Structures
Topic: Help on 2.51
Replies: 3
Views: 157

Re: Help on 2.51

To find the unpaired electrons, select the outer most valence electron, identify if it is s d p f orbital, draw out how many electrons on the outer most valence electron, and determine how many are unpaired.
I attached a file to illustrate
by Alejandro Salazar 1D
Fri May 11, 2018 7:24 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge: Lewis dot structures
Replies: 6
Views: 247

Re: Formal Charge: Lewis dot structures

I am confused about when we can add double bonds versus when we just add electrons to certain elements in the given compound to make the formal charge closer to zero. How would we know what the best way to do that is in order to draw the proper Lewis dot structure? On the attached file, you can see...
by Alejandro Salazar 1D
Sun May 06, 2018 9:16 pm
Forum: Empirical & Molecular Formulas
Topic: Test 1/ Question 8 [ENDORSED]
Replies: 6
Views: 387

Test 1/ Question 8 [ENDORSED]

I would really appreciate if someone could explain question number 8 on Test 1 (Wednesday Section).

What information are we supposed to know for this problem? How would I get the mass of the molecule?
by Alejandro Salazar 1D
Sat May 05, 2018 3:20 pm
Forum: Photoelectric Effect
Topic: In class problem 5/4
Replies: 3
Views: 190

In class problem 5/4

Q. No electrons are emitted from the surface of the metal until the frequency of the radiation reaches 2.50 times 10^16 Hz. How much energy is required to remove the electron from the metal surface I did get the correct answer for this part which was 1.66x10^-17 J Q. In the first question what is th...
by Alejandro Salazar 1D
Sat May 05, 2018 2:59 pm
Forum: Balancing Chemical Reactions
Topic: Test 1 Q3
Replies: 2
Views: 189

Re: Test 1 Q3

It is hard to know when to use fractions especially on this one. But if you consider a more simpler equation like C2H6 +02 --> CO2+H20 C2H6+O2 --> 2CO2+ 3H2O C:2 C:2 H:6 H:6 O:2 O:7 There is no number you can multiply two from the oxygen on the reactant side to get 7 from the product side. I find it...
by Alejandro Salazar 1D
Sat May 05, 2018 2:23 pm
Forum: Molarity, Solutions, Dilutions
Topic: Test 1, Q1 [ENDORSED]
Replies: 4
Views: 388

Re: Test 1, Q1 [ENDORSED]

For part A, did you get M= 73.9. I'm not sure if I did correctly either. I simply used M= n(number of moles)/V(Liters)
by Alejandro Salazar 1D
Sat Apr 28, 2018 8:59 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Coefficients in electron configurations [ENDORSED]
Replies: 4
Views: 234

Re: Coefficients in electron configurations [ENDORSED]

The 4 correspond to the group period on the left of the periodic table
by Alejandro Salazar 1D
Sat Apr 28, 2018 8:50 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Why does the 4s orbital come before the 3d?
Replies: 7
Views: 263

Re: Why does the 4s orbital come before the 3d?

The electron configuration for Cr is different, by having the 3d come first before the 4s because having two electrons in the 4s makes the orbital more unstable because of electron repulsion
by Alejandro Salazar 1D
Sat Apr 28, 2018 8:34 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Aufbau Principle Diagrams [ENDORSED]
Replies: 2
Views: 125

Re: Aufbau Principle Diagrams [ENDORSED]

I think it has to do with energy difference. Next to the Aufbau diagram, theres a y-axis labeled as Energy, energy increases as it goes up. There is a bigger gap between the s orbital than the p orbital because it requires more energy for electron to move.
by Alejandro Salazar 1D
Sat Apr 28, 2018 8:27 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: In class problem [ENDORSED]
Replies: 6
Views: 340

Re: In class problem [ENDORSED]

I believe the answer has to be smaller than the speed of light 3.00 x10^8 m/s to make sense. In this case, 3.4 x 10^10 m/s is larger than the speed of light, so the object is too large
by Alejandro Salazar 1D
Sun Apr 22, 2018 11:55 pm
Forum: Properties of Light
Topic: Homework #1.7 [ENDORSED]
Replies: 2
Views: 133

Re: Homework #1.7 [ENDORSED]

2.0 and 7.1 both have two sig figs. Usually you determine the number of sig figs based on the given numbers. It is based on the lowest number of sig figs
by Alejandro Salazar 1D
Sun Apr 15, 2018 9:01 pm
Forum: Administrative Questions and Class Announcements
Topic: Memorizing equations [ENDORSED]
Replies: 5
Views: 259

Re: Memorizing equations [ENDORSED]

I think most constants are given as well as most but not all equations. I feel like we are more required to know how to use an equation if given than memorizing
by Alejandro Salazar 1D
Sun Apr 15, 2018 8:58 pm
Forum: Balancing Chemical Reactions
Topic: Balancing Chemical Reactions
Replies: 5
Views: 249

Re: Balancing Chemical Reactions

Hi, there's a similar helpful post already under, "How to balance". A technique for more complex equations. Balance compounds that appear once. Often, it is required to use fractions and then multiply the entire equation by the denominator of the function to cancel out the fraction.
by Alejandro Salazar 1D
Sun Apr 15, 2018 3:43 pm
Forum: Properties of Light
Topic: Properties of Light [ENDORSED]
Replies: 5
Views: 190

Re: Properties of Light [ENDORSED]

I'm not sure if this helps your question but light behaves BOTH like a wave and a particle. Wave-particle duality
by Alejandro Salazar 1D
Sun Apr 15, 2018 2:02 pm
Forum: Balancing Chemical Reactions
Topic: Suggestions for Balancing Reactions
Replies: 8
Views: 371

Re: Suggestions for Balancing Reactions

There's a similar post already under "How to balance"

A technique for more complex equations. Balance compounds that appear once. Often, it is required to use fractions and then multiply the entire equation by the denominator of the function to cancel out the fraction
by Alejandro Salazar 1D
Sun Apr 15, 2018 12:32 pm
Forum: Balancing Chemical Reactions
Topic: How to Balance [ENDORSED]
Replies: 5
Views: 183

Re: How to Balance [ENDORSED]

A technique for more complex equations. Balance compounds that appear once. Often, it is required to use fractions and then multiply the entire equation by the denominator of the function to cancel out the fraction.
by Alejandro Salazar 1D
Sun Apr 15, 2018 10:52 am
Forum: Limiting Reactant Calculations
Topic: Finding Excess Amount of Reactant [ENDORSED]
Replies: 2
Views: 127

Re: Finding Excess Amount of Reactant [ENDORSED]

When you convert g× mol/g ×mol/mol twice to determine the limiting reactant, you choose the reactant in moles with the lowest value since that's the one that will "run out" first For Excess reactant it is similar, but instead choose the higher value that is in moles. Depending on the quest...

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