Search found 90 matches

by Kayla Maldonado 1A
Mon Feb 24, 2020 2:43 pm
Forum: Balancing Redox Reactions
Topic: Homework Question 6K.5 (part b)
Replies: 1
Views: 8

Homework Question 6K.5 (part b)

Balance each of the following skeletal equations by using oxidation and reduction half-reactions. All the reactions take place in basic solution. Identify the oxidizing agent and reducing agent in each reaction. b). Reaction of bromine with itself (disproportionation) in aqueous solution: Br 2 (l) -...
by Kayla Maldonado 1A
Sun Feb 23, 2020 2:07 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Galvanic/Voltaic cells
Replies: 3
Views: 9

Re: Galvanic/Voltaic cells

We can see galvanic cells in non-rechargeable batteries where there is a spontaneous redox reaction in the flow of electrical charges and electrons flow from the anode (negative since electrons are built up here) to the cathode (positive since it is gaining electrons).
by Kayla Maldonado 1A
Sun Feb 23, 2020 2:01 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Positive Voltage
Replies: 2
Views: 7

Positive Voltage

In this course should we always assume a more positive standard reduction meaning the reaction is more likely to undergo reduction and be on the cathode side (will lead to a positive voltage) ? If not how can we find out if the reaction will be on the anode side vs the cathode side?
by Kayla Maldonado 1A
Sun Feb 23, 2020 1:50 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Voltage Energies
Replies: 3
Views: 13

Re: Voltage Energies

When calculating the equation for overall cell potential you do not need to change the sign of E naught for the reverse reaction.
by Kayla Maldonado 1A
Sun Feb 23, 2020 1:46 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Using Pt
Replies: 7
Views: 25

Re: Using Pt

When is it necessary to use Pt(s) in the skeletal equation of a redox reaction? In the example that Dr. Lavelle gave in class: 2Fe3+(aq) + Cu(s) -> Cu2+(aq) + 2Fe2+ although platinum is part of the redox reaction, platinum is an inert conductor that is transferring e-, as there is no conducting sol...
by Kayla Maldonado 1A
Sun Feb 23, 2020 1:43 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Finding n
Replies: 6
Views: 20

Re: Finding n

"n" means moles of electrons and can easily be found by looking at your balanced redox reaction and looking at the number of electrons that were transferred. So this is the number of moles of electrons transferred after the entire redox reaction and not the total of electrons transferred ...
by Kayla Maldonado 1A
Sun Feb 16, 2020 3:43 am
Forum: Van't Hoff Equation
Topic: What is this? [ENDORSED]
Replies: 7
Views: 80

Re: What is this? [ENDORSED]

What are the constants in this equation? (example: constant pressure)
by Kayla Maldonado 1A
Sun Feb 16, 2020 3:32 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: delta U= delta H
Replies: 4
Views: 16

Re: delta U= delta H

Delta U= q+w and under constant pressure, qp=delta H and when no work is done Delta U=Delta H
by Kayla Maldonado 1A
Sun Feb 16, 2020 3:00 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: spontaneity
Replies: 23
Views: 64

Re: spontaneity

A negative delta G means that the reaction is spontaneous.
by Kayla Maldonado 1A
Sun Feb 16, 2020 2:37 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Delta E
Replies: 10
Views: 32

Delta E

What is the difference between delta E and delta U?
by Kayla Maldonado 1A
Sun Feb 16, 2020 2:29 am
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: Boltzmann Equation
Replies: 10
Views: 27

Re: Boltzmann Equation

Sartaj Bal 1J wrote:The Boltzmann equation is used to represent the relationship between degeneracy, w, and entropy. Degeneracy is the number of ways of achieving a given energy state. The Boltzmann equation also includes the Boltzmann constant which is 1.381*10^-23 J*K^-1.

Can we calculate degeneracy? If so how?
by Kayla Maldonado 1A
Sun Feb 09, 2020 1:50 am
Forum: Calculating Work of Expansion
Topic: 4A.3 part c
Replies: 3
Views: 18

Re: 4A.3 part c

Usually delta U=q+w but there is not heat (q) exchanged in this problem so delta U= w
by Kayla Maldonado 1A
Sun Feb 09, 2020 1:45 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: reversible vs irreversible work
Replies: 7
Views: 27

Re: reversible vs irreversible work

Sometimes it's also easy to think conceptually whether a process can be undone (reversible) or not (irreversible) such as combustion, once something is burned then it cannot be undone, therefore it is an irreversible system.
by Kayla Maldonado 1A
Sun Feb 09, 2020 1:20 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: HW Question
Replies: 2
Views: 16

Re: HW Question

The system consists of both kettle + water, and the surroundings supply the heat. Enough supplied heat is needed to raise the temperature of both the vessel and the water because of the idea that heat moves from a hot object to a cold object so both need to be heated because if just the vessel is he...
by Kayla Maldonado 1A
Sun Feb 09, 2020 12:59 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Confused about Heat of Combustion
Replies: 2
Views: 13

Re: Confused about Heat of Combustion

She may be referring to the equation
q=n*C*(delta T)
where q is heat transferred, n is # of moles, C is the molar heat capacity, and delta T is change in temperature.
by Kayla Maldonado 1A
Sun Feb 09, 2020 12:50 am
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: Going from delta S to delta H
Replies: 2
Views: 15

Re: Going from delta S to delta H

delta S(surrounding)= -delta H/T
This equation can manipulated to solve for delta H given delta S
by Kayla Maldonado 1A
Sun Feb 02, 2020 3:23 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Closed vs isolated systems
Replies: 24
Views: 64

Re: Closed vs isolated systems

In a closed system, matter does not change, but the energy (heat) can with the surroundings. In an isolated system matter doesn't change and energy cannot change meaning that the system is insulated.
by Kayla Maldonado 1A
Sun Feb 02, 2020 3:20 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Enthalpy vs. Heat
Replies: 6
Views: 19

Re: Enthalpy vs. Heat

PranaviKolla2B wrote:Does anyone have any good videos explaining enthalpy and the related equations?

https://www.khanacademy.org/science/che ... v/enthalpy
by Kayla Maldonado 1A
Sun Feb 02, 2020 3:13 am
Forum: Calculating Work of Expansion
Topic: Reversible vs. Irreversible
Replies: 1
Views: 15

Re: Reversible vs. Irreversible

Irreversible reactions are reactions in which the reactants convert to products and where the products cannot convert back to the reactants. In reversible reactions, as the reactants react with other reactants to form products, the products are reacting with other products to form reactants. Reversi...
by Kayla Maldonado 1A
Sun Feb 02, 2020 2:21 am
Forum: Calculating Work of Expansion
Topic: L atm and J
Replies: 3
Views: 15

Re: L atm and J

The joules unit number 101.33 J converts to 1 l atm, one Liter-atmosphere. It is the equal energy value of 1 Liter-atmosphere but in the joules energy unit alternative.
by Kayla Maldonado 1A
Sun Feb 02, 2020 2:10 am
Forum: Ideal Gases
Topic: pv=nrt
Replies: 9
Views: 35

Re: pv=nrt

Kind of like what the previous person said, R is a gas constant, so that can't really be changed (given on our equations sheet). For everything else though, yes there could be change. That's also where the mini-questions during lectures are formed "What would happen to ____ if ____ increased?&...
by Kayla Maldonado 1A
Sat Jan 25, 2020 7:06 pm
Forum: Phase Changes & Related Calculations
Topic: revere reactions
Replies: 7
Views: 28

Re: revere reactions

Would this be the same for going up a phase? Would it be endothermic in this case since now there is more heat required to break down the phase like a solid to liquid? Yes going up a phase requires energy to be absorbed otherwise defined as an endothermic reaction in order to go from a solid (low e...
by Kayla Maldonado 1A
Sat Jan 25, 2020 7:02 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Heat Capacity
Replies: 5
Views: 23

Re: Heat Capacity

Molar heat capacity is the amount of heat needed to raise the temperature of one mole of a pure substance by one degree Kelvin. Specific heat capacity is the amount of heat necessary to raise the temperature of one gram of a pure substance by one degree Kelvin.
by Kayla Maldonado 1A
Sat Jan 25, 2020 6:59 pm
Forum: Phase Changes & Related Calculations
Topic: Endothermic and Exothermic
Replies: 13
Views: 33

Re: Endothermic and Exothermic

Endothermic Reactions require heat or absorb it to overcome the activation energy to form products. In an exothermic reaction, heat is released or "exits" the reaction to form the product and no longer can overcome the activation energy in the reverse reaction unless more heat is absorbed.
by Kayla Maldonado 1A
Sat Jan 25, 2020 6:53 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: enthalpy reaction
Replies: 4
Views: 19

Re: enthalpy reaction

Elena Bell 1C wrote:We do reactants minus the products for bond enthalpies because it is broken minus made. The bonds broken require energy, while forming bonds releases energy.

Why is it that in order to break bonds, energy is needed? And to form bonds energy is released?
by Kayla Maldonado 1A
Sat Jan 25, 2020 6:49 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Excluding H2O from Ka and Kb
Replies: 5
Views: 14

Re: Excluding H2O from Ka and Kb

Water is a pure liquid and has an activity equal to 1, therefore, it does not affect the equilibrium constant.
by Kayla Maldonado 1A
Sun Jan 19, 2020 12:20 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Concentrations
Replies: 12
Views: 39

Re: Concentrations

I'm not sure if this answers your question but if the temperature is the same the concentration does not change the equilibrium constant (k). However, if you change the temperature it does change the equilibrium constant. So temperature is the only thing that can affect the the equilibrium constant ?
by Kayla Maldonado 1A
Sun Jan 19, 2020 12:16 am
Forum: Ideal Gases
Topic: R constant in Ideal Gas Law
Replies: 4
Views: 15

R constant in Ideal Gas Law

How do we know what units to use for the R constant in the Ideal Gas Law?
by Kayla Maldonado 1A
Sat Jan 18, 2020 11:16 pm
Forum: Ideal Gases
Topic: Ideal Gas meaning
Replies: 7
Views: 41

Re: Ideal Gas meaning

Kevin Antony 2B wrote:At low temperatures, most gases are going to act ideally. In this course, we'll probably only deal with ideal gases because this allows for us to apply PV=nRT and infer molecular kinetic energy based on temperature.

How do we know when to apply the ideal gas equation in a problem?
by Kayla Maldonado 1A
Sat Jan 18, 2020 11:14 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5 %
Replies: 4
Views: 16

Re: 5 %

If you solve Ka or Kb by the approximate method and exceed 5% in order to obtain as accurate an answer as possible, the quadratic method must be used. So I guess, it's just a method of making finding the solution simpler instead of going through the whole quadratic formula if it isn't necessary.
by Kayla Maldonado 1A
Sat Jan 18, 2020 10:52 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Le Chatliers Principle In relation to pressure
Replies: 6
Views: 18

Re: Le Chatliers Principle In relation to pressure

According to the ideal gas law, PV = nRT, P = nRT/V = concentration (=n/V) * RT. So [partial pressure = concentration * RT]. The way I see it is concentration is moles per liter which means the more moles, the higher the Molarity or Concentration, and as said in the comment above, partial pressure ...
by Kayla Maldonado 1A
Sat Jan 11, 2020 4:43 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Significance of principle
Replies: 6
Views: 21

Re: Significance of principle

Le Chatelier's principle can be used to predict the behavior of a system due to changes in pressure, temperature, or concentration. This principle states that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium shifts to counteract the change to reestablish ...
by Kayla Maldonado 1A
Sat Jan 11, 2020 4:39 pm
Forum: Ideal Gases
Topic: R in PV=nRT
Replies: 34
Views: 366

Re: R in PV=nRT

PV=nRT is the Ideal Gas Law equation. To answer your question, the R is the ideal gas law constant and there are varying corresponding values (for the most part, problems will specify which value to use.) Some examples can include bar or atm. When do we use the ideal gas law equation? How does it r...
by Kayla Maldonado 1A
Sat Jan 11, 2020 3:54 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Why does only Temp affect K?
Replies: 10
Views: 53

Re: Why does only Temp affect K?

Temperature affects K c because the forward reaction is either exothermic or endothermic. If the forward reaction is endothermic, then the K c value will be larger when the temperature is higher since the forward reaction will absorb the added heat and produce a greater proportion of products to re...
by Kayla Maldonado 1A
Sat Jan 11, 2020 3:49 pm
Forum: Ideal Gases
Topic: Solids and Liquids [ENDORSED]
Replies: 10
Views: 65

Re: Solids and Liquids [ENDORSED]

I agree with Fiona and McKenna! However, I am still confused on the matter of liquids being pure substancews. Can someone clarify how a liquid is different from an aqueous solution and give examples of each? From what I understand, aqueous solutions have a solute and solvent, and liquids do not. Ca...
by Kayla Maldonado 1A
Sat Jan 11, 2020 2:13 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE Tables
Replies: 5
Views: 20

Re: ICE Tables

Yes an ICE box is only used for gases and aqueous reagents because they are not pure substances and can change over the course of a reaction. In establishing equilibrium constants, solids and liquids are not used/considered due to the fact that they're pure substances that don't change.
by Kayla Maldonado 1A
Sat Dec 07, 2019 11:03 pm
Forum: Coordinate Covalent Bonds
Topic: Cisplatin
Replies: 3
Views: 33

Cisplatin

What else besides knowing that the Cl atoms in cisplatin can attach to DNA bases to initiate cell death in chemotherapy is necessary to know about cisplatin?
by Kayla Maldonado 1A
Sat Dec 07, 2019 10:43 pm
Forum: Bronsted Acids & Bases
Topic: Amphoteric
Replies: 2
Views: 40

Re: Amphoteric

Amphoteric molecules usually contain the elements that lie on the diagonal border (metalloids) between the metals and nonmetals where metallic character blends into non-metallic character and the oxides of these elements have both acidic and basic character.
by Kayla Maldonado 1A
Sat Dec 07, 2019 10:27 pm
Forum: Administrative Questions and Class Announcements
Topic: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
Replies: 111
Views: 4124

Re: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]

CHo_3I wrote:
SarahSteffen_LEC4 wrote:On question number 21 of the Marshmallow review. Why does iron have a +2 charge if two of the nitrogens on the porphyrin ligand have a +1 charge?


The two nitrogens actually have a -1 charge, not +1.


How is the charge for the nitrogens -1?
by Kayla Maldonado 1A
Sat Dec 07, 2019 9:49 pm
Forum: Administrative Questions and Class Announcements
Topic: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
Replies: 111
Views: 4124

Re: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]

#16 why is the trigonal planar shape considered nonpolar, how did we determine this ?
by Kayla Maldonado 1A
Sat Dec 07, 2019 5:01 pm
Forum: Administrative Questions and Class Announcements
Topic: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
Replies: 111
Views: 4124

Re: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]

Joanne Kang 3I wrote:min marshmallows 1c... why isn't it neutral?

NH4+ donates a proton and H20 accepts a proton, therefore NH4+is acidic.
by Kayla Maldonado 1A
Fri Dec 06, 2019 1:52 pm
Forum: Dipole Moments
Topic: Intermolecular Forces
Replies: 3
Views: 29

Intermolecular Forces

Are London Dispersion forces and Van Der Waals forces the same type of intermolecular force? Why is there always Van Der Waals forces?
by Kayla Maldonado 1A
Fri Dec 06, 2019 12:32 am
Forum: Naming
Topic: Naming Anionic Ligands
Replies: 3
Views: 33

Naming Anionic Ligands

When we name anionic ligands in coordination compounds do we refer to anions that end in -ide as -ido or just -o as a replacement because the book uses -ido and Dr. Lavelle presents both in his LIGAND NAMES IN COORDINATION COMPOUNDS pdf. An example is chloride, when it is named in a coordination com...
by Kayla Maldonado 1A
Sun Dec 01, 2019 1:36 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate = more than one lone pair?
Replies: 4
Views: 31

Re: Polydentate = more than one lone pair?

Can we determine the denticity (monodentate, bidentate, polydentate, etc.) of a ligand by simply looking at the coordination compound name? If so, how?
by Kayla Maldonado 1A
Sun Dec 01, 2019 1:21 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: strong or weak base?
Replies: 13
Views: 55

Re: strong or weak base?

A strong base is a base that is 100% ionized in solution and if it is less than 100% ionized in solution, it is a weak base. All strong bases are OH– compounds.
by Kayla Maldonado 1A
Sun Dec 01, 2019 1:10 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: dipole-dipole in a solid phase vs gas phase
Replies: 15
Views: 94

Re: dipole-dipole in a solid phase vs gas phase

With gases, they occupy more space so the attraction between the molecules are weak. Solids on the other hand are more restricted in their movement, so they have stronger dipole-dipole interactions than gases would. So are all intermolecular bonds between gases generally weaker than those between s...
by Kayla Maldonado 1A
Sun Dec 01, 2019 1:03 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Amphoteric vs. Amphiprotic
Replies: 4
Views: 24

Re: Amphoteric vs. Amphiprotic

Amphoteric refers to the ability to react with an acid or base. An amphiprotic substance is a substance that transfers (accepts or donates) H+ ions.
by Kayla Maldonado 1A
Sun Dec 01, 2019 12:36 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Sigma and Pi Bonds
Replies: 12
Views: 329

Re: Sigma and Pi Bonds

All bonds have at least one sigma bond the other bonds are pi bonds.
by Kayla Maldonado 1A
Sat Nov 23, 2019 4:02 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: Boiling Points
Replies: 9
Views: 55

Re: Boiling Points

I'm confused between the melting point and the boiling point of a compound? Is this referring to the same thing? There is a difference in which the boiling point is the temperature where a material goes from liquid to a gas and melting point is the temperature where a material changes from a solid ...
by Kayla Maldonado 1A
Sat Nov 23, 2019 3:37 pm
Forum: Administrative Questions and Class Announcements
Topic: Thanksgiving Break
Replies: 4
Views: 47

Re: Thanksgiving Break

My TA sent out an email saying that if you do not have discussion this week both week 9 and 10 homework can be turned in the following week. I'm not sure if it's like this for all TA's.
by Kayla Maldonado 1A
Sat Nov 23, 2019 3:32 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Bronsted acids
Replies: 5
Views: 47

Re: Bronsted acids

A Bronsted acid is an H+ donor (proton donor), and a bronsted base is an H+ acceptor (proton acceptor). In order for a bronsted base to accept an H+ ion, it uses its lone pair of electrons to bind to it. You can then see the connection between a bronsted base and a Lewis base (<- electron pair dono...
by Kayla Maldonado 1A
Sat Nov 23, 2019 3:28 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Sphere
Replies: 6
Views: 35

Re: Coordination Sphere

The first coordination sphere is all molecules or ions directly attached the central metal atom shown below.
by Kayla Maldonado 1A
Sat Nov 23, 2019 12:18 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Uncertainty about ligands
Replies: 2
Views: 25

Re: Uncertainty about ligands

A ligand is an ion or molecule that binds to a central metal atom to form a coordination complex. Ligands are Lewis bases due to the availability of a lone pair of electrons that can be donated to create a coordinate covalent bonds.
by Kayla Maldonado 1A
Sat Nov 23, 2019 12:04 am
Forum: Biological Examples
Topic: Ringlike structures + chelating ligands
Replies: 2
Views: 16

Re: Ringlike structures + chelating ligands

A ligand is chelating if it has two or more points of attachment or coordinate covalent bonds to a metal atom or metal ion. When a ligand is chelating a ring structure is formed creating ring-forming groups known as chelating groups.
by Kayla Maldonado 1A
Sun Nov 17, 2019 1:15 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Van Der Waals Interaction
Replies: 11
Views: 52

Van Der Waals Interaction

Do all molecules have Van Der Waals interactions? What is the order of strongest to weakest interactions ?
by Kayla Maldonado 1A
Sun Nov 17, 2019 12:38 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pairs
Replies: 6
Views: 52

Re: Lone Pairs

lone pairs count towards molecular geometry not electron domain geometry. so in the case of 4 electron domains (3 bonding and one lone pair), the electron domain geometry would be tetrahedral while the molecular geometry would be trigonal pyramidal. So if asked in a question what shape a certain mo...
by Kayla Maldonado 1A
Sat Nov 16, 2019 6:19 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent or Angular
Replies: 13
Views: 97

Re: Bent or Angular

So, the bond angle in H 2 O is 104.5 degrees (from the textbook). On test 2, should we state that the bond angle for all angular molecules is 104.5 degrees or should we just say less than 120 degrees? Angular molecules can have varying bond angles depending on the amount of lone pairs there are suc...
by Kayla Maldonado 1A
Sat Nov 16, 2019 6:08 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR and Polarity
Replies: 4
Views: 24

Re: VSEPR and Polarity

Polar molecules are asymmetrical in electronegativity and the geometry or formation. Asymmetrical electronegativity meaning there is an atom with a partial positive charge surrounding an atom with a partial negative charge with an electronegativity difference of 0.5-1.6. Asymmetrical formation assur...
by Kayla Maldonado 1A
Sat Nov 16, 2019 5:44 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Shape
Replies: 6
Views: 59

Re: Shape

DesireBrown3K wrote:This photo is from the textbook of all the shapes we should know for test 2.

[img]Screenshot%202019-11-16%2017.24.28.png[/img]


The book names what Dr. Lavelle called "bent" as "angular" which is the correct term to use?
by Kayla Maldonado 1A
Thu Nov 07, 2019 3:48 pm
Forum: SI Units, Unit Conversions
Topic: Photons
Replies: 3
Views: 55

Re: Photons

If eV is on the test convert it to joules(on the equation sheet) to ensure you are still in SI units but eV is used to measure energy and can thus measure the energy in a photon.
by Kayla Maldonado 1A
Thu Nov 07, 2019 3:47 pm
Forum: Bond Lengths & Energies
Topic: Bond strengths
Replies: 9
Views: 47

Re: Bond strengths

A longer bond means a weaker bond as the interaction between the atoms is weaker. Shorter bonds mean a strong pull between the nuclei of the two atoms and thus it requires more energy to break which means it is stronger.
by Kayla Maldonado 1A
Thu Nov 07, 2019 3:43 pm
Forum: Octet Exceptions
Topic: Easy way to remember octet exceptions
Replies: 4
Views: 35

Re: Easy way to remember octet exceptions

Any atom with a d orbital has the octet exception. Atoms in row one and two only have the p and s orbitals and thus eight valence electrons, the p orbital has six and the s orbital two. With the addition of a d orbital, atoms are able to accommodate more than eight valence electrons by putting some ...
by Kayla Maldonado 1A
Thu Nov 07, 2019 3:39 pm
Forum: Electronegativity
Topic: Trend of Electronegativity
Replies: 22
Views: 106

Re: Trend of Electronegativity

Does ionization have the same trend? Ionization energy has the exact same trend. Ionization energy and electronegativity go hand in hand, the more electronegative an atom is the more it wants an electron and thus the more tightly it will hold on to its own electrons. Across a period, atoms gain pro...
by Kayla Maldonado 1A
Thu Nov 07, 2019 3:36 pm
Forum: Electronegativity
Topic: Trend of Electronegativity
Replies: 22
Views: 106

Re: Trend of Electronegativity

Electronegativity increases in an overall diagonal line starting with Francium as the least electronegative and Fluorine as the most electronegative. This occurs because as you move up a period, the number of valence shells decreases meaning the atom is getting smaller which in turn means the proton...
by Kayla Maldonado 1A
Thu Nov 07, 2019 3:32 pm
Forum: Lewis Structures
Topic: When to draw Resonance Structures
Replies: 14
Views: 82

Re: When to draw Resonance Structures

How do we know when a molecule has resonance? A molecule has resonance when it has a bond that can be drawn in a different place and not alter the overall formal charge of the atom or molecule itself. For example, if you have a carbon single bonded to two oxygen and single bonded to another, you ca...
by Kayla Maldonado 1A
Sun Nov 03, 2019 2:11 am
Forum: Electronegativity
Topic: Electronegativity
Replies: 9
Views: 52

Electronegativity

When drawing lewis structures will we be given the electronegativity table to determine which atom will be the central atom?
by Kayla Maldonado 1A
Sun Nov 03, 2019 2:06 am
Forum: Lewis Structures
Topic: Exceptions to the octet rule
Replies: 3
Views: 23

Re: Exceptions to the octet rule

How do we know how many valence electrons an element with an expanded octet has? How are lone pairs shown in a lewis dot structure?
by Kayla Maldonado 1A
Sun Nov 03, 2019 1:46 am
Forum: Properties of Light
Topic: Equations
Replies: 4
Views: 28

Re: Equations

The reference sheet will most likely be like the one given on the first test. It did include these equations, but did not give the name of each equation.
by Kayla Maldonado 1A
Sun Nov 03, 2019 1:28 am
Forum: Lewis Structures
Topic: central atom
Replies: 16
Views: 142

Re: central atom

Arianna Perea 3H wrote:why is the central atom the one with the least electronegativity?

The least electronegative elements are in the center of lewis structures because an atom in the central position shares more of its electrons than does an atom on the sides of the central atom or the terminal position.
by Kayla Maldonado 1A
Sun Nov 03, 2019 1:10 am
Forum: Dipole Moments
Topic: Definition
Replies: 5
Views: 55

Re: Definition

Dipole Moment refers to the momentary positive or negative charge which exists on an atom when the electrons are temporarily located at a given position on it. It is represented by an arrow placed between the partial positive and partial negative charges on two atoms, with the arrow pointing toward...
by Kayla Maldonado 1A
Sat Oct 26, 2019 7:30 pm
Forum: Lewis Structures
Topic: Lewis Structure
Replies: 5
Views: 46

Re: Lewis Structure

The least electronegative elements are in the center of lewis structures because an atom in the central position shares more of its electrons than does a terminal atom such as Hydrogen which is never found in the center.
by Kayla Maldonado 1A
Sat Oct 26, 2019 7:24 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Ionization Energy
Replies: 4
Views: 22

Ionization Energy

When talking about ionization energy, why is it that it's harder to remove a 2nd electron from an atom and does this mean that there are multiple ionization energies for an element?
by Kayla Maldonado 1A
Sat Oct 26, 2019 6:54 pm
Forum: Ionic & Covalent Bonds
Topic: Resonance (all bonds are a hybrid of different bonds)
Replies: 10
Views: 74

Re: Resonance (all bonds are a hybrid of different bonds)

How can you tell if a compound has resonance and do all resonance forms need to be drawn when being asked for a lewis dot diagram?
by Kayla Maldonado 1A
Sat Oct 26, 2019 6:43 pm
Forum: Ionic & Covalent Bonds
Topic: Does the Octet Rule apply to Boron?
Replies: 14
Views: 87

Re: Does the Octet Rule apply to Boron?

Both Boron and Aluminum are both satisfied with six valence electrons instead of 8 as implied by the octet rule.
by Kayla Maldonado 1A
Sat Oct 26, 2019 6:13 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic and Covalent Bonds
Replies: 4
Views: 27

Ionic and Covalent Bonds

How do you know whether or not two elements share a covalent or ionic bond and why?
by Kayla Maldonado 1A
Sun Oct 20, 2019 12:54 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: quantum number n, l, m
Replies: 13
Views: 87

Re: quantum number n, l, m

n represents the principal quantum number which is the shell that the electron is located on. l is the angular momentum quantum number and it describes the shape of the orbital. It can either be an s orbital, p orbital, d orbital, or f orbital. m is the magnetic quantum number and it tells you the ...
by Kayla Maldonado 1A
Sun Oct 20, 2019 12:42 pm
Forum: Properties of Electrons
Topic: Wave-like and particle-like properties
Replies: 7
Views: 47

Re: Wave-like and particle-like properties

All things have wave-particle duality, but due to the behavior of large objects, they act more as particles than waves. Things that are quantized have behaviors that must consider both the wave properties and particle properties such as electrons.
by Kayla Maldonado 1A
Sun Oct 20, 2019 1:35 am
Forum: Photoelectric Effect
Topic: The Rydberg Formula and the Hydrogen Atomic Spectrum
Replies: 4
Views: 35

The Rydberg Formula and the Hydrogen Atomic Spectrum

I'm still confused as to if Rydberg's formula can work for only for the hydrogen emission spectrum? Why or Why not?
by Kayla Maldonado 1A
Sun Oct 20, 2019 12:21 am
Forum: *Shrodinger Equation
Topic: wavefunctions & orbitals relationship?
Replies: 5
Views: 72

Re: wavefunctions & orbitals relationship?

Due to the fact that orbitals act as waves, a wave function is a mathematical function that shows the wave-like behavior of electron(s) in an atom and the probable location to finding an electron in a specific region around the nucleus of an atom.
by Kayla Maldonado 1A
Sun Oct 20, 2019 12:15 am
Forum: Properties of Electrons
Topic: Energy increasing
Replies: 7
Views: 76

Re: Energy increasing

Increasing in energy levels refers to an electron within an atom when they absorb enough energy to move from a lower to higher energy level.
by Kayla Maldonado 1A
Sat Oct 12, 2019 2:54 am
Forum: Properties of Electrons
Topic: Wave properties
Replies: 5
Views: 34

Re: Wave properties

After determining the wavelength (m) using De Broglie's wave equation use the answer to determine if it's below any # x 10^-15 in scientific notation, if it is then it's considered to have wavelike properties and if it's above that it does not have wavelike properties. The smaller the wavelength, th...
by Kayla Maldonado 1A
Sat Oct 12, 2019 2:22 am
Forum: Properties of Electrons
Topic: Electron After Excited State
Replies: 7
Views: 36

Re: Electron After Excited State

When an electron gets excited, it absorbs energy and jumps to a higher energy level. An excited electron can release energy in the form of a photon and "fall" to a lower state due to the fact that an excited electron is unstable and rearranges itself to return to its lower energy state.
by Kayla Maldonado 1A
Sat Oct 12, 2019 2:00 am
Forum: Properties of Electrons
Topic: Mass of Electron in De Broglie Equation
Replies: 4
Views: 37

Mass of Electron in De Broglie Equation

In one example given in lecture, we are asked to calculate the De Broglie wavelength of an electron traveling at a specific velocity (m.s^-1) and the question given doesn't include the mass (kg) of an electron. Are we suppose to already know or memorize the mass of an electron or is the information ...
by Kayla Maldonado 1A
Sat Oct 12, 2019 1:40 am
Forum: Einstein Equation
Topic: Planck's Constant
Replies: 3
Views: 41

Re: Planck's Constant

Planck's Constant is defined as the quantum of action and shown to be a constant of proportionality between energy and the frequency in one photon according to Einstein.
by Kayla Maldonado 1A
Sat Oct 12, 2019 1:19 am
Forum: Properties of Electrons
Topic: Wave-Particle Duality
Replies: 1
Views: 16

Re: Wave-Particle Duality

In quantum mechanics, wave-particle duality is seen in objects with small masses in which they can sometimes act as waves or particles. For example, an electron with wave-particle duality can be released and travel outward emitting a wave, but as it reaches a surface that it can bounce off, it will ...
by Kayla Maldonado 1A
Thu Oct 03, 2019 5:12 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Fundamentals E.3
Replies: 7
Views: 87

Re: Fundamentals E.3

I multiplied the 9 gallium atoms by the molar mass, 70 g.mol^-1 and made it equal to a variable, "x" representing the number of astatine atoms because it's unknown and multiplied that by the molar mass of astatine, 210 g.mol^-1. From there the variable I received was 3 atoms of astatine. T...
by Kayla Maldonado 1A
Thu Oct 03, 2019 4:52 pm
Forum: Limiting Reactant Calculations
Topic: Homework Week 1
Replies: 18
Views: 204

Re: Homework Week 1

Any five questions can be answered for 5 pts per week for the homework. More can be done for practice, but only 5 need to be turned in.
by Kayla Maldonado 1A
Thu Oct 03, 2019 12:21 am
Forum: Empirical & Molecular Formulas
Topic: Naming Molecular Compounds
Replies: 6
Views: 53

Re: Naming Molecular Compounds

I am also struggling with naming compounds, but reviewing outside sources like khan academy has helped a bit. I also don't think it will be necessary for now, but we most likely will need the skill later.
by Kayla Maldonado 1A
Wed Oct 02, 2019 11:12 pm
Forum: Balancing Chemical Reactions
Topic: Balancing Chemical Equations Formatting
Replies: 6
Views: 105

Re: Balancing Chemical Equations Formatting

In this case when reactants/products are formatted in that way you only need to distribute the subscript to the elements in parantheses. In the example you give, Mg(N3)2(s) is equal to MgN6(s).
by Kayla Maldonado 1A
Mon Sep 30, 2019 8:49 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Mole ratios
Replies: 4
Views: 80

Re: Mole ratios

You might be referring to the molar ratios found in the empirical formula in saying 1 mol of NaCl to 1 mole of H2O after balancing the equations using stoichiometric coefficients. In saying 0.018 mol NaCl and then referring to the 1:1 ratio, this also implies that there is 0.018 mol of H2O.

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