Search found 50 matches

by Sharon Rodriguez 3H
Sat Dec 07, 2019 11:25 pm
Forum: Identifying Acidic & Basic Salts
Topic: amphoteric salts
Replies: 1
Views: 155

amphoteric salts

Will we have to know how to identify whether an amphoteric salt given is more acidic, basic, or neutral? This requires using the ionization constants but I am unsure if we need to know how to calculate this.
by Sharon Rodriguez 3H
Fri Dec 06, 2019 11:11 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: electron withdrawing groups
Replies: 1
Views: 35

electron withdrawing groups

What are some important/common electron withdrawing groups that we should look out for? Also could somebody further explain differences between electron withdrawing groups and electron donating groups? Thanks!
by Sharon Rodriguez 3H
Fri Dec 06, 2019 11:02 am
Forum: Identifying Acidic & Basic Salts
Topic: deciding whether the solution of a salt is basic, acidic, or neutral
Replies: 5
Views: 76

Re: deciding whether the solution of a salt is basic, acidic, or neutral

This will likely be information we need to know for the final. If questions do not directly ask about it, the concepts themselves will help regardless!
by Sharon Rodriguez 3H
Fri Dec 06, 2019 11:00 am
Forum: Bronsted Acids & Bases
Topic: Formic acid strength
Replies: 2
Views: 45

Re: Formic acid strength

An acid will be stronger if it can easily lose hydrogen to a base. The CH3 in acetic acid donates electrons which makes the O-H bond stronger due to electronegativity therefore the H is harder to remove, which isn't what we want. This makes formic acid the stronger acid. Basically CH3 is electron do...
by Sharon Rodriguez 3H
Fri Dec 06, 2019 10:54 am
Forum: Amphoteric Compounds
Topic: Transition Metals
Replies: 1
Views: 112

Re: Transition Metals

Amphoteric compunds can react with both acids or bases. The most common amphoteric substance is water so that is always good to know. There are 5 amphoteric elements which are Be, Al, Zn, Sn, and Pb. The oxides and hydroxides of those elements are amphoteric compounds. Hope this helps!
by Sharon Rodriguez 3H
Sat Nov 30, 2019 11:47 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Complexes
Replies: 1
Views: 39

Re: Complexes

Yes, you should be aware of what complexes are as we discussed it for a portion of lecture. Things such as chelates and naming coordination compounds involve comlpexes. Remember that transition metal cations form complexes.
by Sharon Rodriguez 3H
Sat Nov 30, 2019 11:34 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate
Replies: 3
Views: 22

Re: Polydentate

Since they are ligands, the lone pairs must be bonded to the central metal ion and the ligands act as Lewis bases while the central atom acts as the Lewis acid. From there, the number of lone pairs determines if it is a polydentate (more than 1 lone pair).
by Sharon Rodriguez 3H
Sat Nov 30, 2019 11:23 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate = more than one lone pair?
Replies: 4
Views: 48

Re: Polydentate = more than one lone pair?

Unidentates have only one lone pairs but anything with more than one will be considered a polydentate such as a bidentate ligands which have two lone pairs. The lone pairs can all bond to the central metal ion.
by Sharon Rodriguez 3H
Sat Nov 30, 2019 11:09 pm
Forum: Identifying Acidic & Basic Salts
Topic: salt and water formation
Replies: 5
Views: 54

Re: salt and water formation

Both water and salt are produced when strong acids and strong bases react. So for a strong acid + weak base, water is not usually formed since weak bases are not typically hydroxides. A weak acid + strong base the result is basic. A weak acid + weak base depends on the relative strength of the react...
by Sharon Rodriguez 3H
Sat Nov 30, 2019 10:52 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted or Lewis Definition?
Replies: 6
Views: 71

Re: Bronsted or Lewis Definition?

I would say that just to be safe, we should specifically point out that OH- is the Bronsted base and Na+ is a spectator ion.
by Sharon Rodriguez 3H
Sun Nov 24, 2019 2:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Non-polar atoms with lone pairs
Replies: 4
Views: 41

Re: Non-polar atoms with lone pairs

The majority of the time it is true that if a molecule has lone pairs, it will be polar. There are cases, like stated above, where molecules have lone pairs but are nonpolar. Remember to keep in mind the molecular geometry and dipole moments when considering this, there will always be exceptions so ...
by Sharon Rodriguez 3H
Wed Nov 20, 2019 9:53 pm
Forum: Sigma & Pi Bonds
Topic: pi bond locations
Replies: 3
Views: 67

pi bond locations

How would you know if the pi bonds of a molecule are perpendicular to each other vs. parallel? In the case of H2CCCH2, the C=C pi bonds are parallel to each other but in H2CCCH2 the C=C pi bonds are parallel. Would we have to know this for test 2?
by Sharon Rodriguez 3H
Wed Nov 20, 2019 8:49 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 2
Replies: 1
Views: 44

Re: Test 2

Everything that was not covered on the midterm so dipole moments, intermolecular forces (LDF, dipole-induced-dipole, induced-dipole-induced-dipole, hydrogen bonds, ion-dipole, ion-ion), molecular geometry so VSEPR, identifying polar and nonpolar molecules, types of bonds (sigma and pi). The cutoff w...
by Sharon Rodriguez 3H
Wed Nov 20, 2019 2:37 pm
Forum: Dipole Moments
Topic: Identifying Induced-Dipole
Replies: 3
Views: 47

Re: Identifying Induced-Dipole

Adding on to what was said above, dipole-induced-dipoles aka london dispersion forces are temporary and depend of the number of electrons in an atom (it's polarizability) and typically, larger molecules are more polarizable. Nonpolar molecules with more number of e- have more LDF than polar molecule...
by Sharon Rodriguez 3H
Wed Nov 20, 2019 2:00 pm
Forum: Dipole Moments
Topic: lone pairs and polarity
Replies: 2
Views: 43

lone pairs and polarity

How do lone pairs on the central atom affect the dipole moments and polarity of the molecule? Do lone pairs have their own dipole moment and how would you determine where the dipole moment would point towards? Like for ammonia, :NH3, I have seen the dipole for N's lone pair to point away from N, why...
by Sharon Rodriguez 3H
Mon Nov 18, 2019 7:33 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Distinguishing forces
Replies: 2
Views: 28

Distinguishing forces

How do you know go about distinguishing what type of forces molecules have when interacting? How do you guys find it best to remember them, any tips? I tend to get confused between all the dipole forces. Thanks!
by Sharon Rodriguez 3H
Mon Nov 18, 2019 9:21 am
Forum: Sigma & Pi Bonds
Topic: Sigma and Pi Bonds
Replies: 8
Views: 111

Re: Sigma and Pi Bonds

haileyramsey-1c wrote:Pi bonds are bonds formed by side by side overlap of two p orbitals. Sigma bonds are two electrons in a cylindrically symmetrical cloud between two atoms. Pi bonds occur in p orbitals and sigma bonds occur in s orbitals.


Are d-orbitals ever relevant in these situations?
by Sharon Rodriguez 3H
Sat Nov 16, 2019 2:53 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: biological examples?
Replies: 3
Views: 39

biological examples?

What would be some relevant biological and inorganic examples of intermolecular forces and hydrogen bonding that we should probably know?
by Sharon Rodriguez 3H
Tue Nov 05, 2019 7:24 pm
Forum: Octet Exceptions
Topic: free radicals
Replies: 1
Views: 40

free radicals

Apart from Nitrogen, what other elements that can break the octect rule due to free radicals should we watch out for and is there how do you remember it?
by Sharon Rodriguez 3H
Tue Nov 05, 2019 2:09 pm
Forum: Octet Exceptions
Topic: placing radicals
Replies: 2
Views: 45

placing radicals

In nitrogen monoxide, NO, the radical can be assigned to both the nitrogen and the oxygen, right? It would depend on what the question asks but if asked for the "most stable" would you put the radical on oxygen since it is more electronegative? Also, is this considered resonance (the radic...
by Sharon Rodriguez 3H
Tue Nov 05, 2019 11:30 am
Forum: Photoelectric Effect
Topic: max and min frequency
Replies: 1
Views: 56

max and min frequency

How would you find the lowest/highest frequency that will cause photoelectric emission if you are given the work function? From what I understand, the kinetic energy in both cases would be 0, leaving the workfunction = hc/lambda, is this correct?
by Sharon Rodriguez 3H
Tue Nov 05, 2019 9:38 am
Forum: Octet Exceptions
Topic: octet exceptions
Replies: 11
Views: 181

Re: octet exceptions

Elements that are period 3 and beyond in the periodic table have access to the d-orbitals, which can fill up to 10 extra valence electrons. One example of this is SF6, where sulfur has 6 bonds to each fluorine atom and thus has 12 valence electrons. Some elements, such as B and Al can have incomple...
by Sharon Rodriguez 3H
Tue Nov 05, 2019 9:06 am
Forum: Trends in The Periodic Table
Topic: electron affinity
Replies: 4
Views: 62

Re: electron affinity

This really clarified it for me, thank you!
by Sharon Rodriguez 3H
Mon Nov 04, 2019 9:28 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 4s or 3d first?
Replies: 14
Views: 360

Re: 4s or 3d first?

The 4s orbitals have a lower energy than the 3d orbitals, so the 4s orbitals are filled first. However, Lavelle has said to write 3d first. Even though 4s is lower in energy, is this where valence electrons would reside? I was under the impression by things I have read that valence e- consisted of ...
by Sharon Rodriguez 3H
Mon Nov 04, 2019 9:20 pm
Forum: Trends in The Periodic Table
Topic: electron affinity
Replies: 4
Views: 62

electron affinity

I understand why energy is required when removing an electron for ionization energy, however I am having trouble understanding why energy is generally released when adding an electron. Could somebody explain this?
by Sharon Rodriguez 3H
Sun Nov 03, 2019 11:14 pm
Forum: Lewis Structures
Topic: expanding an octect
Replies: 5
Views: 64

Re: expanding an octect

They did mention 18 once but I wasn't sure as I have heard other things but yes this helped thank you!
by Sharon Rodriguez 3H
Sun Nov 03, 2019 7:24 pm
Forum: Lewis Structures
Topic: expanding an octect
Replies: 5
Views: 64

expanding an octect

When drawing out a Lewis structure with a central molecule that is an exception to the octect rule, is it likely that most of the time you will have to expand the octect? What is the max amount of electrons that an expanded octect can hold?
by Sharon Rodriguez 3H
Sun Nov 03, 2019 7:20 pm
Forum: Resonance Structures
Topic: Resonance with radicals
Replies: 1
Views: 46

Resonance with radicals

If there is a radical, would it still be possible to have resonance? How would the electron move in that case?
by Sharon Rodriguez 3H
Sat Nov 02, 2019 3:48 pm
Forum: Resonance Structures
Topic: resonance hybrid vs resonance structure
Replies: 2
Views: 38

resonance hybrid vs resonance structure

What is the difference between a resonance hybrid and resonsance structure?
by Sharon Rodriguez 3H
Sat Nov 02, 2019 3:31 pm
Forum: Ionic & Covalent Bonds
Topic: Dissociation energy
Replies: 3
Views: 28

Dissociation energy

How is the dissociation energy obtained?
by Sharon Rodriguez 3H
Sat Nov 02, 2019 3:15 pm
Forum: Lewis Structures
Topic: Midterm Topics
Replies: 8
Views: 73

Re: Midterm Topics

Everything before interactions between ions and molecules is fair game. I believe a larger portion of the midterm will consist ofquantum.
by Sharon Rodriguez 3H
Sat Nov 02, 2019 3:12 pm
Forum: Ionic & Covalent Bonds
Topic: covalent character of ionic bonds
Replies: 4
Views: 49

Re: covalent character of ionic bonds

The greater the polarizing power of the cation or the polarizability on an anion is, then the percentage of covalent characters will also be greater. If the cation is smaller, there is a greater polarizing power so there will be more covalent characters. Similarly, the larger an anion is means great...
by Sharon Rodriguez 3H
Mon Oct 28, 2019 9:53 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Midterm
Replies: 6
Views: 104

Midterm

Is VSEPR going to be covered in the midterm? Especially now that classes were cancelled and we won't get to go over today's material.
by Sharon Rodriguez 3H
Mon Oct 28, 2019 9:51 am
Forum: Octet Exceptions
Topic: aufbau principle
Replies: 8
Views: 143

aufbau principle

Why does 3d^10 have less energy than 4s^2? Could somebody explain the "switch" in energies that occurs in this area of electron configurations?
by Sharon Rodriguez 3H
Mon Oct 28, 2019 9:46 am
Forum: Ionic & Covalent Bonds
Topic: delocalization
Replies: 3
Views: 43

delocalization

Could somebody explain what it means when electrons involved in resonance are delocalized?
by Sharon Rodriguez 3H
Sun Oct 20, 2019 3:18 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Nodal Plane
Replies: 3
Views: 37

Re: Nodal Plane

A nodal plane is a plane where the probabilty of finding an electron is zero. The s-orbitals do not have one due to the spherical shape, there are no angular nodes possible. Any s-orbital has an angular momentum number, l, of 0.
by Sharon Rodriguez 3H
Wed Oct 16, 2019 1:08 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Electron spin
Replies: 8
Views: 145

Electron spin

I understand how to get the other quantum numbers however the spin state seems very conceptual. Are we ever going to be expected to figure out the spin state and if so, how would you go about doing that?
by Sharon Rodriguez 3H
Tue Oct 15, 2019 8:37 pm
Forum: Photoelectric Effect
Topic: Speed of Light
Replies: 29
Views: 326

Re: Speed of Light

The speed of light will always be a constant and is labeled in equations as the variable "c". It is somewhere around 3.0 X 10^8 m/s. On exams, make sure to use the exact number for the speed of light that is given to you on the equation sheet of the exam. This will help you with getting t...
by Sharon Rodriguez 3H
Tue Oct 15, 2019 8:31 pm
Forum: Photoelectric Effect
Topic: Velocity of photoelectron
Replies: 1
Views: 49

Velocity of photoelectron

When a problem is asking for the velocity of the photoelectron produced, assuming the work function and wavelength are given, how would you go about finding the solution? The wording of problems is confusing at times to me as they don't explicity ask for something or the steps to solve it involve us...
by Sharon Rodriguez 3H
Tue Oct 15, 2019 3:25 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Best Way To Study?
Replies: 56
Views: 1174

Re: Best Way To Study?

Doing practice problems and lessons on Khan Academy has helped me so far! I also find that explaining concepts to others or having others explain to me, whether it be here or in person, really helps me to truly understand the concepts. Discussing each other's confusion and seeing things from another...
by Sharon Rodriguez 3H
Tue Oct 15, 2019 3:21 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Radius
Replies: 4
Views: 81

Re: Atomic Radius

I believe this is the simplest way to find the atomic radius without having to do any calculations.
by Sharon Rodriguez 3H
Mon Oct 14, 2019 10:38 pm
Forum: Properties of Light
Topic: HW Question 1.B.19
Replies: 2
Views: 25

Re: HW Question 1.B.19

This question is asking you to calculate the wavelength of each particle (proton & neutron) when travelling at 2.75 x10^5 m.s^-1 and report the difference as a percentage of wavelength of the neutron. First off, you would use λ=h/mv as we are trying to find the wavelength. First, use this equati...
by Sharon Rodriguez 3H
Mon Oct 14, 2019 10:29 pm
Forum: *Shrodinger Equation
Topic: H=E
Replies: 1
Views: 64

Re: H=E

HΨ=EΨ is the time-independent Schrodinger's equation which considers the electron as a standing wave. This is a mathematical model stating is that the sum of the wavefunction's kinetic energy and potential energy (aka the Hamiltonian operator) is equal to the wavefunction's total energy. It is an ei...
by Sharon Rodriguez 3H
Mon Oct 14, 2019 9:35 pm
Forum: Properties of Electrons
Topic: atomic spectroscopy
Replies: 5
Views: 64

Re: atomic spectroscopy

Yes, atomic spectroscopy is the study of electromagnetic radiation emitted and absorbed by atoms. When an atom absorbs energy, it's electrons will jump to a higher energy level and if an atom emits energy then the electrons will jump down to a lower energy level. These so called jumps have a certain...
by Sharon Rodriguez 3H
Tue Oct 08, 2019 1:09 pm
Forum: Properties of Light
Topic: Hw Question 1A.9
Replies: 5
Views: 79

Re: Hw Question 1A.9

You know the energy of the photon (E) and we know E=hv with h being Planck's constant (6.626x10^-34 J.s) so the only unknown in this equation would be v, the frequency. Rearange the equation to solve for v which would be v=E/h. After plugging in the values and finding the answer, you can find the wa...
by Sharon Rodriguez 3H
Sat Oct 05, 2019 5:12 pm
Forum: Properties of Light
Topic: Rydberg, Balmer and Lyman confusion
Replies: 1
Views: 39

Re: Rydberg, Balmer and Lyman confusion

From my understanding, the Rydberg equation is to determine the wavelengths of the line in the hydrogen emission spectrum, therefore this equation only applies to hydrogen atoms, not all elements (that is beyond what we need to know). The Balmer series applies when the lowest energy level possible o...
by Sharon Rodriguez 3H
Sat Oct 05, 2019 4:52 pm
Forum: Properties of Light
Topic: The units for Frequency
Replies: 3
Views: 41

Re: The units for Frequency

Whenever there is an exponent of -1, it is equivalent to (in this case) 1/s simply meaning per second. The same thing goes for things such as g.mol^-1 which is equivalent to g/mol.
by Sharon Rodriguez 3H
Tue Oct 01, 2019 11:45 pm
Forum: Limiting Reactant Calculations
Topic: Post-Module Assessment Question 18
Replies: 6
Views: 125

Re: Post-Module Assessment Question 18

That makes sense, I forget to simplify the ratios so I'll make sure to catch that now. Also, appreciate that alternate way of solving for limiting reactants and the location in the textbook, thank you!
by Sharon Rodriguez 3H
Tue Oct 01, 2019 11:31 pm
Forum: Limiting Reactant Calculations
Topic: Limiting Reactant Lecture Question
Replies: 5
Views: 170

Re: Limiting Reactant Lecture Question

It is likely impossible to have an absoulte exact 1:1 ratio as one reactant will always be completely used and the other may have a minute amount of excess. I would assume that such a small amount is considered insignificant so in those cases you can just see it as being an equal reaction with no li...
by Sharon Rodriguez 3H
Tue Oct 01, 2019 11:18 pm
Forum: Limiting Reactant Calculations
Topic: Post-Module Assessment Question 18
Replies: 6
Views: 125

Re: Post-Module Assessment Question 18

I compared the experimental mole ratios of NH3 and O2 to the ratios of the stoichiometric coefficients given in the problem. As you probably calculated: 21.4 g NH3 = 1.2566 mol NH3 42.5 g O2 = 1.328125 mol O2 In the reactant side of the given chemical equation, the ratio of NH3: O2 = 4:5. Based on ...

Go to advanced search