Search found 30 matches

by Alexander Hari 1L
Mon Jun 04, 2018 8:44 pm
Forum: Octet Exceptions
Topic: expanded octet
Replies: 12
Views: 558

Re: expanded octet

Elements in the 1st and 2nd period do not have access to the the d orbital which prevents them from having an expanded octet, therefore elements that are in the 3rd period and below have the potential to expand their octet.
by Alexander Hari 1L
Mon Jun 04, 2018 8:26 pm
Forum: Lewis Acids & Bases
Topic: 12.13.A Significance of lone pairs in determining Lewis acid/base?
Replies: 3
Views: 124

12.13.A Significance of lone pairs in determining Lewis acid/base?

NH3 Lewis structure shows 1 lone pair on N. The answer key has this molecule listed as a lewis base. Is this because of the lone pair? Can someone explain this?
by Alexander Hari 1L
Mon Jun 04, 2018 8:19 pm
Forum: Bronsted Acids & Bases
Topic: How to identify a Bronsted acid or base
Replies: 11
Views: 704

How to identify a Bronsted acid or base

Can anyone offer some tips/examples on how to identify if a molecule is an acid or a base specifically Bronsted protons?
by Alexander Hari 1L
Sat Jun 02, 2018 3:50 pm
Forum: Hybridization
Topic: σ vs π bond tips thread
Replies: 5
Views: 177

σ vs π bond tips thread

Thread on making tips on how to memorize σ vs π bonds
One way I remember the difference is the pi symbol has 2 "legs" extending from the symbol itself, and in lecture Dr. Lavelle gave the example of two markers connected and if you attempt to spin it on its axis, then the bond breaks.
by Alexander Hari 1L
Sat Jun 02, 2018 3:38 pm
Forum: Hybridization
Topic: basics of hybridization
Replies: 18
Views: 659

Re: basics of hybridization

I found this video pretty helpful, in case anyone else needs further explanation on hybridization: https://www.youtube.com/watch?v=vyT5YF4UEy0
by Alexander Hari 1L
Sat Jun 02, 2018 3:34 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent vs. Angular
Replies: 11
Views: 357

Re: Bent vs. Angular

@ Elizabeth, they are the same thing, bent and angular can be used interchangeably regardless of lone pairs (according to my TA)
by Alexander Hari 1L
Thu May 24, 2018 12:33 pm
Forum: Octet Exceptions
Topic: Help on 3.59 in homework?
Replies: 2
Views: 146

Re: Help on 3.59 in homework?

Not sure if this helps, but I think the answer key simply chose Cl as their example of a radical instead of O. Also, I double bonded my lewis structure unlike the textbook to have a radical with Cl, a formal charge of 0, and O has its full Octet.
by Alexander Hari 1L
Thu May 24, 2018 12:18 pm
Forum: Ionic & Covalent Bonds
Topic: Help on 3.13
Replies: 1
Views: 86

Re: Help on 3.13

If you look at the periodic table and locate Zinc we can see it has an electron configuration of [Ar] 3d10 4s2. If you want to make a +1 ion of Zn, you must remove one electron from this element. You can just take away one electron from the 4s block because it is the outermost shell. Also, you would...
by Alexander Hari 1L
Wed May 23, 2018 11:21 pm
Forum: Resonance Structures
Topic: Kekulé Structures??
Replies: 6
Views: 324

Re: Kekulé Structures??

No, it might be nice to know Kekulé structures, however, for the exams they would want us to write out the entire Lewis Structure
by Alexander Hari 1L
Mon May 14, 2018 8:14 pm
Forum: Lewis Structures
Topic: HW 3.49.C
Replies: 1
Views: 76

HW 3.49.C

Hi, part C asks for the Lewis structure and Formal charge of CO
I got :C=O::
with a formal charge of 0 on both C and O, however, the answer key gives a formal charge of 1, and -1 with a single bond. Are both answers acceptable or am I breaking any rules with this? Thanks!
by Alexander Hari 1L
Mon May 14, 2018 8:02 pm
Forum: Lewis Structures
Topic: Benzine
Replies: 3
Views: 130

Re: Benzine

I think to be safe on an exam, they'd probably want you to write out the entire structure to know you understand formal charge, lewis structures, bonds etc. As for multiple different structures as said previously they most likely will only ask for one possible structure rather than every possible st...
by Alexander Hari 1L
Mon May 14, 2018 6:41 pm
Forum: Ionic & Covalent Bonds
Topic: HW problem 3.21
Replies: 4
Views: 190

Re: HW problem 3.21

Remember that the d orbital likes to be full so the extra electron that would have been in the 5s block is instead placed in the 4d^9 orbital to make 4d^10. This would mean you have no unpaired electrons, so the answer key is correct
by Alexander Hari 1L
Thu May 10, 2018 2:56 pm
Forum: Trends in The Periodic Table
Topic: Relationship between Ionic Radius, Atomic RdiuIonization Enrgy, Electron Affinity
Replies: 3
Views: 255

Re: Relationship between Ionic Radius, Atomic RdiuIonization Enrgy, Electron Affinity

You can think of ionization energy and electron affinity as kind of opposites. Ionization energy is the amount of energy required to remove an electron while electron affinity is the energy required to add an electron. It might be helpful to remember the difference by thinking of affinity as somethi...
by Alexander Hari 1L
Thu May 10, 2018 2:51 pm
Forum: Quantum Numbers and The H-Atom
Topic: Homework Question 2.41
Replies: 3
Views: 221

Re: Homework Question 2.41

Mohamad is correct, to find the value of l you first start with the value of n which in this case is 5. To solve for l, you use the equation n-1=l. Therefore, the only possible solution of l would be 5-1 to give a value of l=4.
by Alexander Hari 1L
Thu May 10, 2018 2:48 pm
Forum: Ionic & Covalent Bonds
Topic: Difference between anions and cations?
Replies: 3
Views: 117

Difference between anions and cations?

I'm still having trouble between how these two work. From my understanding, an anion is an element such as C- that is a Carbon atom that lost an electron, so if it has one less electron shouldn't it be more similar to Boron which is one element to the left and not like Nitrogen which would have one ...
by Alexander Hari 1L
Sun May 06, 2018 7:27 pm
Forum: Quantum Numbers and The H-Atom
Topic: Spin Direction [ENDORSED]
Replies: 4
Views: 249

Re: Spin Direction [ENDORSED]

They have no preference themselves to spin up or spin down, we just simply tend to write arrows pointing upwards to save time and for consistency. Although when two electrons occupy a single orbital, one must spin up while the other spins down.
by Alexander Hari 1L
Sun May 06, 2018 7:18 pm
Forum: Quantum Numbers and The H-Atom
Topic: 2.29 b & d
Replies: 3
Views: 160

Re: 2.29 b & d

ml is the possible number of electrons, the reason it has 5 possible values (-2, -1, 0, 1, 2) is because we don't know exactly how many electrons there are.
by Alexander Hari 1L
Sun May 06, 2018 7:10 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: half full?
Replies: 5
Views: 150

Re: half full?

Amanda, half-filled orbitals or full orbitals are more stable than a subshell with only a few electrons because the atom is trying to gain or lose electrons to meet either of those stages. For example a 2p orbital can contain up to 6 electrons. It's happier state is either 3 or 6, and if it is at 4 ...
by Alexander Hari 1L
Sun May 06, 2018 7:04 pm
Forum: Trends in The Periodic Table
Topic: Largest in Atomic Radii?
Replies: 5
Views: 121

Re: Largest in Atomic Radii?

If you think of it in terms of gravity this may help: If you know that an element has a large number of protons, it tends to have a larger pull on its electrons because the "gravitational pull" of the protons is higher. If you have a single Cl atom its atomic number is 17 which means it ha...
by Alexander Hari 1L
Sun May 06, 2018 6:48 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Textbook question 1.17
Replies: 1
Views: 116

Re: Textbook question 1.17

The atomic number of Helium is 2 so Z should be 2 as well, my textbook gives an answer for 1.17 as 30.4nm which is the wavelength and the question asks for wavelength not energy. Maybe your solution manual is for a different edition or simply converted it to Joules instead of wavelength?
by Alexander Hari 1L
Sun May 06, 2018 6:37 pm
Forum: Limiting Reactant Calculations
Topic: Test 1
Replies: 4
Views: 239

Re: Test 1

I do not think there was an official answer key released
by Alexander Hari 1L
Sat Apr 21, 2018 3:34 pm
Forum: Properties of Light
Topic: Speed of Light which is more accurate? [ENDORSED]
Replies: 6
Views: 216

Speed of Light which is more accurate? [ENDORSED]

When we are calculating equations involving the speed of light, is it better to use 3.00x10^8 or 2.998x10^8? Does it really make a difference? Thanks.
by Alexander Hari 1L
Thu Apr 19, 2018 10:27 pm
Forum: Properties of Light
Topic: Part B on HW 1.25
Replies: 1
Views: 80

Part B on HW 1.25

I calculated parts a and c, however, I am having trouble with what I am suppose to do with the 5.00mg of sodium atoms. The question is: "Sodium vapor lamps, used for public lighting, emit yellow wavelength 589nm. How much energy is emitted by: b) 5.00mg of sodium atoms emitting light at this wa...
by Alexander Hari 1L
Thu Apr 19, 2018 7:51 pm
Forum: DeBroglie Equation
Topic: HW 1.41 Help with understanding final answer
Replies: 1
Views: 126

HW 1.41 Help with understanding final answer

I calculated the velocity of question 41: "What is the velocity of a neutron of wavelength 100. pm" I used the equation v=(h x lambda)/mass of a neutron and got 3.96 x 10^-24m, but the answer in the back of the book says 3.96 x 10^3m. How is this the answer? What did I do incorrectly? Than...
by Alexander Hari 1L
Sun Apr 15, 2018 7:00 pm
Forum: Properties of Light
Topic: Speed of Light
Replies: 2
Views: 89

Speed of Light

Does the value of the speed of light change when it is not in a vacuum? Also what constitutes a vacuum exactly? Can someone explain?
by Alexander Hari 1L
Sun Apr 15, 2018 6:57 pm
Forum: SI Units, Unit Conversions
Topic: Extensive vs. Intensive Properties?
Replies: 3
Views: 239

Extensive vs. Intensive Properties?

I'm still having trouble understanding the difference between the two properties, can someone give an example of both?
by Alexander Hari 1L
Sun Apr 15, 2018 6:49 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molarity
Replies: 3
Views: 123

Re: Molarity

I think in this problem, you need to convert the initial grams to moles and then multiply by the initial volume (75mL) and then set it equal to Mfinalx125mL since MinitialVinitial=MfinalVfinal, then solve for Mfinal
by Alexander Hari 1L
Wed Apr 11, 2018 5:54 pm
Forum: Balancing Chemical Reactions
Topic: Fastest way to balance chemical equation
Replies: 9
Views: 1269

Re: Fastest way to balance chemical equation

When I am balancing an equation that contains O2, I usually leave that for last because it can simply be multiplied at the end with the rest of the equation balanced. Also, if it is a relatively long chemical equation I write each individual element on its own and its corresponding amount on both th...
by Alexander Hari 1L
Wed Apr 11, 2018 5:45 pm
Forum: Limiting Reactant Calculations
Topic: Question 8 on UA's Practice Test
Replies: 3
Views: 125

Question 8 on UA's Practice Test

"For the following reaction, how many grams of AlCl3 would be obtained if 5.43g of aluminum and 7.80g of hydrogen chloride (HCl) was used in the reaction? Al (s) + HCl (aq) → AlCl3 (aq) + H2 (g)" I've figured out that the limiting reactant in the equation is HCl and that we have 0.21 moles...
by Alexander Hari 1L
Thu Apr 05, 2018 8:59 pm
Forum: Balancing Chemical Reactions
Topic: H.5.b [ENDORSED]
Replies: 7
Views: 276

H.5.b [ENDORSED]

I am having trouble figuring out how to balance part H.5.b. Which is: Mg(N3)2(s)+H2O(l)-->Mg(OH)2(aq)+HN3(aq).. I am not sure how we are suppose to distribute the numbers following the parenthesis. Do we multiply it out so? For example, would Mg(N3)2 become MgN6? Or is there some other way we are su...

Go to advanced search