Search found 86 matches

by Simon Dionson 4I
Mon Feb 10, 2020 5:18 pm
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: Entropy
Replies: 2
Views: 13

Entropy

Why do molecules and atoms with greater mass have more molar entropy?
by Simon Dionson 4I
Sat Feb 08, 2020 4:36 pm
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: Degeneracy
Replies: 1
Views: 11

Degeneracy

When counting positions on a complex molecule, would we count lone pairs as their own position? For example, would NH3 have 4 possible positions?
by Simon Dionson 4I
Sat Feb 08, 2020 3:10 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 4F.11
Replies: 1
Views: 17

4F.11

I'm confused as to why neither (3R/2) or (5R/2) are used for nitrogen; they just used R by itself as N2's ideal heat capacity.

Another general question I have is when to use 3R/2 and 5R/2 for heat capacities when calculating entropy.
by Simon Dionson 4I
Sat Feb 08, 2020 2:46 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Entropy equations
Replies: 2
Views: 17

Entropy equations

Will the entropy equations for isothermal expansion/compression, pressure change, and heat change be on the midterm?
by Simon Dionson 4I
Fri Feb 07, 2020 1:59 pm
Forum: Administrative Questions and Class Announcements
Topic: Discussion 4I
Replies: 1
Views: 44

Discussion 4I

Hey everyone, I left my black Ray bans in Bunche 3211 in the back row of the classroom for discussion 4I (Friday’s 12-12:50) on Friday 2/7. If you have them, would you mind returning them? My name is Simon Dionson and I have lectures MWF from 3-3:50.
by Simon Dionson 4I
Fri Feb 07, 2020 12:59 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 4F.9
Replies: 2
Views: 14

Re: 4F.9

Sean Cheah 1E wrote:Because the process is isothermal, q = -w. Decreasing pressure must mean that volume is increasing, therefore work is negative. Then q is positive and delta S = q/T is also positive.


Oh, that makes sense. Thank You! I think I interpreted decreasing pressure as decreasing volume.
by Simon Dionson 4I
Fri Feb 07, 2020 11:20 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 4F.9
Replies: 2
Views: 14

4F.9

If the pressure of a gas in a container is decreased isothermally, wouldn't the entropy change be negative? The answer key is saying that it is positive.
by Simon Dionson 4I
Fri Feb 07, 2020 11:09 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 4f.7
Replies: 1
Views: 16

4f.7

How do we know to use 5/2R and 3/2R for constant pressure and volume?
by Simon Dionson 4I
Fri Feb 07, 2020 10:50 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 4f.1
Replies: 2
Views: 10

4f.1

Is it incorrect to report the entropy change in Celcius rather than kelvin?
by Simon Dionson 4I
Sat Feb 01, 2020 2:29 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat capacity
Replies: 2
Views: 12

Heat capacity

Is it possible for a heat capacity to be negative?
by Simon Dionson 4I
Sat Feb 01, 2020 1:12 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Calorimeter
Replies: 3
Views: 15

Calorimeter

Why is there a negative in: q = -C(cal)ΔT. What is this indicating/what is losing heat and gaining heat?
by Simon Dionson 4I
Sat Feb 01, 2020 1:01 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: reaction enthalpy
Replies: 14
Views: 40

Re: reaction enthalpy

Elizabeth Harty 1A wrote:What is the difference between enthalpy and entropy?


Entropy is the disorder of a system, Enthalpy is the measure of heat/energy related to a substance when it is changed.
by Simon Dionson 4I
Sat Feb 01, 2020 12:56 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 4E.5
Replies: 3
Views: 19

Re: 4E.5

Benzene has a special value for bond enthalpy that is noted in the table; I also made the same mistake.
by Simon Dionson 4I
Sat Feb 01, 2020 12:53 pm
Forum: Phase Changes & Related Calculations
Topic: Phase Changes
Replies: 17
Views: 43

Re: Phase Changes

Phase changes are constant to change intermolecular forces. Sloped lines can indicate heat capacities.
by Simon Dionson 4I
Thu Jan 30, 2020 3:17 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond enthalpies
Replies: 4
Views: 19

Bond enthalpies

When calculating a reaction using bond enthalpies, will the answer always be negative (exothermic)?
by Simon Dionson 4I
Thu Jan 30, 2020 2:45 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Calorimeter q
Replies: 2
Views: 13

Calorimeter q

How do we know if q is negative or positive for q(system) when analyzing a bomb calorimeter?
by Simon Dionson 4I
Fri Jan 24, 2020 2:50 pm
Forum: General Science Questions
Topic: Fall 2019 final
Replies: 7
Views: 42

Fall 2019 final

If we took Chem 14A with Lavelle last quarter does anyone know when the final is handed out/if it was already?
by Simon Dionson 4I
Thu Jan 23, 2020 1:15 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5J.13
Replies: 3
Views: 28

Re: 5J.13

At 700k less ammonia is formed since the K value is smaller. The K value being smaller indicates that there is more reactant that product at equilibrium
by Simon Dionson 4I
Thu Jan 23, 2020 1:13 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5J 5: increase in pressure
Replies: 4
Views: 43

Re: 5J 5: increase in pressure

Increasing pressure will favor the side with fewer mols of gas

B) 1mol of H2O vs 1mol of H2 + 1mol CO --> reactants favored
D) 2mol of HD vs 1 mol of H2 + 1mol of D2 --> neither favored since both have 2 mols of gases
by Simon Dionson 4I
Thu Jan 23, 2020 1:07 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Acids and Bases pka and pkb
Replies: 8
Views: 33

Re: Acids and Bases pka and pkb

the -log means that the higher the number, the lower the value. Higher numbers result in stronger acids/bases for pka and pkb.
by Simon Dionson 4I
Thu Jan 23, 2020 12:59 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5% rule
Replies: 13
Views: 40

Re: 5% rule

In my experience, I usually use this rule in weak acid/base equilibria.
by Simon Dionson 4I
Thu Jan 23, 2020 12:52 pm
Forum: Ideal Gases
Topic: Equilibrium Constant
Replies: 7
Views: 27

Re: Equilibrium Constant

Since reactants are represented at the bottom, if the number is smaller than 10^-3 then more reactants are present at equilibrium
by Simon Dionson 4I
Thu Jan 23, 2020 12:51 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Water in K constant
Replies: 6
Views: 20

Re: Water in K constant

Water is only not included if it is a solvent (liquid) or a solid.
by Simon Dionson 4I
Thu Jan 16, 2020 7:41 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 6D.3
Replies: 1
Views: 7

6D.3

Does anyone have the answers for both parts?

For part a, I calculated: K(a) = 0.09, pKa = 1.0

Part b, I calculated: K(b) = 5.7*10^-4, pKb = 3.2

I can't find the solutions so I wanna make sure these are right
by Simon Dionson 4I
Thu Jan 16, 2020 3:29 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Approximating -x
Replies: 3
Views: 13

Approximating -x

When can we approximate x when expressing K(a) or K(b)

i.e. when (x)(0.10+x)/(0.10 - x)

can be approximated to

(x)(0.10 + x)/(0.10)
by Simon Dionson 4I
Wed Jan 15, 2020 7:12 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Strong acids/weak acids
Replies: 3
Views: 17

Strong acids/weak acids

Do strong acids have K(a) values like weak acids do? Or is there even a distinction between K and K(a)?
by Simon Dionson 4I
Tue Jan 14, 2020 6:59 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5J.13
Replies: 4
Views: 23

Re: 5J.13

Tracy Tolentino_2E wrote:Do we not have to calculate anything?


I didn't do any math, I used the K values to base my answers. Since K at the lower temperature was smaller, I assumed more products were formed at 600K vs 700K.
by Simon Dionson 4I
Tue Jan 14, 2020 6:57 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5J.3
Replies: 5
Views: 22

Re: 5J.3

Removal of a product will cause the equilibrium to shift to the right, meaning there will be more reactants consumed to reach equilibrium again.
by Simon Dionson 4I
Tue Jan 14, 2020 6:40 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5J.9b
Replies: 8
Views: 29

5J.9b

If p(NH3) is decreased will O2 increase?

3NH3 + 5O2 = 4NO + 6H2O

My initial answer is yes because the reaction will shift to the left, is this explanation correct?
by Simon Dionson 4I
Sat Jan 11, 2020 1:48 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5I.19
Replies: 1
Views: 18

5I.19

For H2 + I2 <=> 2HI

If 60% of 0.133M H2 has reacted at equilibrium, do I represent the change as - 60% of H2 and the equilibrium concentration as the remaining 40%?
by Simon Dionson 4I
Thu Jan 09, 2020 9:19 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5I.15
Replies: 1
Views: 19

5I.15

To set up the quadratic equation, there would actually be no denominator correct?

NH4HS(s) = NH3(g) + H2S(g)

We would only use NH3 and H2S in the ICE table?
by Simon Dionson 4I
Thu Jan 09, 2020 8:58 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Stability
Replies: 5
Views: 102

Re: Stability

You can also look at the product formed. F2 -> 2F has more atoms formed than Cl2 -> 2Cl, F atoms form more than Cl atoms at the same conditions, so they are more stable.
by Simon Dionson 4I
Tue Jan 07, 2020 7:16 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: P(k) and P(q)
Replies: 2
Views: 30

P(k) and P(q)

If we were calculating a reaction with multiple phases (i.e. solid, liquid, aqueous, gas), will calculating P(q) and P(k) only deal with the gases?
by Simon Dionson 4I
Tue Jan 07, 2020 7:14 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Constant Q
Replies: 2
Views: 31

Constant Q

When calculating Q, do we apply the same rules of not including the concentrations of solids and solvents?
by Simon Dionson 4I
Sat Dec 07, 2019 2:03 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Marshmallow Packet pH
Replies: 3
Views: 155

Re: Marshmallow Packet pH

I don't see the answer key for the marshmallow practice problems so can someone tell me if the answer to 34 is a pH of 2.1? I'm not sure if it's 2.1 or 2.3. CaO + H2O --> Ca(OH)2. There are 2 hydroxides produced for every 1 CaO. If you double the moles of OH-, the answer comes out to 2.276 vs 2.1 i...
by Simon Dionson 4I
Sat Dec 07, 2019 11:39 am
Forum: Properties of Electrons
Topic: Mass of an electron
Replies: 9
Views: 69

Re: Mass of an electron

It will be provided on the front sheet along with other constants and equations.
by Simon Dionson 4I
Sat Dec 07, 2019 11:37 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: orbitals past f
Replies: 4
Views: 53

Re: orbitals past f

The only possible l values are 0, 1, 2, 3 (s, p, d, f respectively)
by Simon Dionson 4I
Sat Dec 07, 2019 11:36 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Listing quantum numbers
Replies: 2
Views: 29

Re: Listing quantum numbers

I think as long as you know the values, you should be fine. I also don't think they'll explicitly mark you down if you assign a random ml value to an atom since they can be in any orientation in a given moment.
by Simon Dionson 4I
Sat Dec 07, 2019 11:34 am
Forum: Properties of Light
Topic: Light Absorbed/ emitted
Replies: 4
Views: 38

Re: Light Absorbed/ emitted

If light is absorbed, a system is receiving an input of energy, so the value is positive. If light is emitted, a system is releasing energy (essentially losing it), so the value is negative.
by Simon Dionson 4I
Mon Dec 02, 2019 5:35 pm
Forum: Identifying Acidic & Basic Salts
Topic: 6D.11b
Replies: 1
Views: 33

6D.11b

If we were to dissolve Na2CO3 in water, would CO3 2- be completely or partially protonated by the water?

i.e.

CO3 2- + 2H2O -> H2CO3 + 2OH-

vs

CO3 2- + H2O -> HCO3- + OH-

Could the same be said for bases with a negative charge greater than 1? thanks.
by Simon Dionson 4I
Sun Dec 01, 2019 5:04 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted Acids and Bases
Replies: 3
Views: 24

Re: Bronsted Acids and Bases

water is amphoteric since it can form H3O+ or OH- if it accepts or donates a proton respectively. Another amphoteric molecule is HCO3- (bicarbonate)

It can accept a proton to form H2CO3 (carbonic acid)
It can also donate a proton to form CO3 2- (carbonate ion)
by Simon Dionson 4I
Sun Dec 01, 2019 4:59 pm
Forum: Bronsted Acids & Bases
Topic: Distinguishing between the different definitions of acids and bases
Replies: 2
Views: 24

Re: Distinguishing between the different definitions of acids and bases

Arrhenius acid: a compound that supplies H+ in water
Arrhenius base: a compound that supplies OH- in water

Brønsted acid: a compound that donates protons
Brønsted base: a compound that accepts protons

Lewis acid: an electron pair acceptor (i.e. H+)
Lewis base: an electron pair donor
by Simon Dionson 4I
Sun Dec 01, 2019 1:22 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 6c.21
Replies: 1
Views: 17

6c.21

Why is acetic acid considered a weaker acid than formic acid? I thought carbon is more electronegative than hydrogen.
by Simon Dionson 4I
Fri Nov 29, 2019 1:40 pm
Forum: Lewis Acids & Bases
Topic: 6A.13
Replies: 7
Views: 34

6A.13

Why is Ag+ considered a Lewis acid and not a Lewis base? Doesn't it have several electron pairs it can donate?
by Simon Dionson 4I
Tue Nov 26, 2019 3:15 pm
Forum: Naming
Topic: HW 9c.9
Replies: 4
Views: 32

HW 9c.9

Is [PtCl2(en)2]2+ coordination number 4 or 6? Does en form a chelate that binds to the platinum more than once?
by Simon Dionson 4I
Sun Nov 24, 2019 11:33 pm
Forum: Electronegativity
Topic: water solubility
Replies: 4
Views: 38

Re: water solubility

Electrons with high electronegativity are likely to form polar bonds which interact with partial charges in water molecules.
by Simon Dionson 4I
Sun Nov 24, 2019 11:17 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: resonance bond rules
Replies: 2
Views: 30

Re: resonance bond rules

I'm guessing resonance structures still apply to the idea that they're hybrids of the resonance structures, so the number of signature and pi bonds don't change based on what resonance structure you use.
by Simon Dionson 4I
Sun Nov 24, 2019 10:44 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Hydrogen Bonding
Replies: 13
Views: 56

Re: Hydrogen Bonding

Yes, but the atom would have to have a partially positive on the hydrogen and there would have to be a strongly electronegative atom, like N, O, or F
by Simon Dionson 4I
Sun Nov 24, 2019 10:40 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: melting point
Replies: 8
Views: 38

Re: melting point

Stronger bonds result in higher melting points, so if bonds were broken, the melting point would decrease
by Simon Dionson 4I
Sun Nov 24, 2019 10:39 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond angles
Replies: 7
Views: 35

Re: Bond angles

Visually, it's similar to a trigonal bipyramidal but you would have to remove one bonding pair. So it would be 90, 180, 120
by Simon Dionson 4I
Sun Nov 17, 2019 3:27 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Will polarizability/polarizing power be on test 2?
Replies: 3
Views: 39

Re: Will polarizability/polarizing power be on test 2?

He explicitly told us on Friday's lecture that only hybridization wouldn't be on the test. I think it would be safe to assume this will be on the test.
by Simon Dionson 4I
Sun Nov 17, 2019 3:26 pm
Forum: Sigma & Pi Bonds
Topic: Hybridization shortcuts
Replies: 1
Views: 21

Hybridization shortcuts

Are there any shortcuts or quick ways of finding an atom's hybridized orbitals?
by Simon Dionson 4I
Sun Nov 17, 2019 3:24 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Trend in polarisability and polarizing power?
Replies: 3
Views: 30

Re: Trend in polarisability and polarizing power?

Polarising power increases with an atom with fewer electrons and is more positively charged (up and left). Polarizability increases with an atom with more electrons and a more negatively charged nucleus (down and right)
by Simon Dionson 4I
Sun Nov 17, 2019 3:22 pm
Forum: Electronegativity
Topic: Symbols for partial charge
Replies: 4
Views: 37

Re: Symbols for partial charge

∂+ and ∂- represent partial charges due to difference in electronegavities. A dipole is indicated by ∂+ --> ∂-
by Simon Dionson 4I
Sun Nov 17, 2019 3:21 pm
Forum: Ionic & Covalent Bonds
Topic: Bonds strength
Replies: 4
Views: 38

Re: Bonds strength

A double bond is stronger than a single bond due to its stability and distance between the bonding atoms. Shorter bond lengths allow attractive forces between atoms to be stronger.
by Simon Dionson 4I
Fri Nov 08, 2019 6:13 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: Dispersion forces
Replies: 6
Views: 40

Re: Dispersion forces

Polarizability is how likely an electron cloud can be distorted in shape. Polarizability also increases with the size of atoms and how many electrons they have. If an atom has more electrons, there is a higher likelihood electrons can gather on one side and create an induced dipole.
by Simon Dionson 4I
Fri Nov 08, 2019 6:09 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: Dispersion
Replies: 3
Views: 16

Re: Dispersion

The more electrons a molecule has, the stronger its induced dipole interactions are. If a molecule/atom has more electrons, they have increased probability of electrons creating a partial charge by gathering on one side of the electron cloud.
by Simon Dionson 4I
Fri Nov 08, 2019 6:05 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: Vapor Pressure
Replies: 2
Views: 25

Vapor Pressure

What is the relationship between the strength of intermolecular forces and vapor pressure?
by Simon Dionson 4I
Fri Nov 08, 2019 6:00 pm
Forum: Ionic & Covalent Bonds
Topic: Polarizability
Replies: 6
Views: 43

Re: Polarizability

Polarizability increases with the size of the electron and how many electrons it has. For example, Iodine has high polarizability because it is a big atom with many electrons compared to something like sodium.
by Simon Dionson 4I
Fri Nov 08, 2019 5:58 pm
Forum: Ionic & Covalent Bonds
Topic: Ionization of Nitrogen vs Oxygen
Replies: 11
Views: 61

Re: Ionization of Nitrogen vs Oxygen

The orbitals of oxygen have one more electron in any of the p orbitals. These create electron-electron repulsions that make it easier to remove an electron than nitrogen.
by Simon Dionson 4I
Sat Nov 02, 2019 8:15 pm
Forum: Ionic & Covalent Bonds
Topic: ionic vs. covalent
Replies: 7
Views: 45

Re: ionic vs. covalent

An ionic bond would be denoted as the cation being [M]+ with the anion having the donated electron(s) surrounding it with a charge [M]-. A covalent bond has a line for each bond its sharing electrons make. H2 is H-H because its electrons make a single bond
by Simon Dionson 4I
Sat Nov 02, 2019 3:06 pm
Forum: *Particle in a Box
Topic: Nodes
Replies: 1
Views: 87

Nodes

Is there a relationship demonstrated between a particle in a box and nodes in an atom? If so, how can it be explained?
by Simon Dionson 4I
Sat Nov 02, 2019 3:02 pm
Forum: DeBroglie Equation
Topic: Dino Nuggets Problem 8b
Replies: 11
Views: 305

Re: Dino Nuggets Problem 8b

To find the kinetic energy of the electron, you actually have to use 2 different equations. Use de Broglie's to find that lambda = h/mv and solve for v. Using the v from de Broglie's equation, find the kinetic energy using E(k) = 1/2(m)(v)^2. Note that m in both these equations is the mass of an ele...
by Simon Dionson 4I
Sat Nov 02, 2019 2:49 pm
Forum: Trends in The Periodic Table
Topic: Ionization Energy from the Review
Replies: 4
Views: 28

Re: Ionization Energy from the Review

In the 2p orbital, all nitrogen's are half-filled with electrons whereas oxygen has one full orbital and two half-filled orbitals. This first full orbital in oxygen has greater electron repulsion than the first half-full orbital in nitrogen, which makes it easier to remove an electron
by Simon Dionson 4I
Sat Nov 02, 2019 2:36 pm
Forum: Photoelectric Effect
Topic: Ionization Energy vs Threshold Energy
Replies: 4
Views: 34

Re: Ionization Energy vs Threshold Energy

Threshold energy is the minimum energy needed to remove an electron from a metal surface (photoelectric effect). Ionization energy is the energy needed to remove an electron from an element.
by Simon Dionson 4I
Sun Oct 27, 2019 4:42 pm
Forum: Trends in The Periodic Table
Topic: Focus 1 1.31 Atoms
Replies: 1
Views: 29

Re: Focus 1 1.31 Atoms

Use E = hc/lambda to find the individual energies of the lasers. Convert the work function from eV to joules. Choose the laser that is greater the work function and from there you have the laser and can calculate the kinetic energy from E = (work function) - (kinetic energy).
by Simon Dionson 4I
Sun Oct 27, 2019 4:11 pm
Forum: Trends in The Periodic Table
Topic: 1F.17
Replies: 1
Views: 19

1F.17

How can you tell exactly what pair of elements exhibit a diagonal relationship? Does it have to do with what ions they can readily form?
by Simon Dionson 4I
Sun Oct 27, 2019 2:40 pm
Forum: Quantum Numbers and The H-Atom
Topic: 1E.17
Replies: 2
Views: 28

1E.17

If an electron is removed from Mn, why is the electron removed from the 4s orbital instead of 3d orbital?
by Simon Dionson 4I
Sun Oct 27, 2019 1:03 pm
Forum: Quantum Numbers and The H-Atom
Topic: 1D.23
Replies: 1
Views: 26

1D.23

Would someone explain to me the answers of b and c? When m(l) in part b is given, is that talking about a specific orbital making the answer 2? For part c, I understand that 2p and 2s can exist, so are the orbitals of those two added together?
by Simon Dionson 4I
Fri Oct 25, 2019 1:42 pm
Forum: Quantum Numbers and The H-Atom
Topic: 1D.19
Replies: 1
Views: 34

1D.19

This question is asking for the number of orbitals present in a given subshell. The answers in the answer guide are given in electrons, but wouldn't the answers be based on the value of 2l and 2l+1?
by Simon Dionson 4I
Sat Oct 19, 2019 5:51 pm
Forum: Properties of Electrons
Topic: Textbook 1B.21
Replies: 2
Views: 21

Re: Textbook 1B.21

We can tell the de Broglie equation must be used because it's relating wavelength, mass, and velocity. The de Broglie uses SI units so you'll have to convert the values given.
by Simon Dionson 4I
Sat Oct 19, 2019 4:43 pm
Forum: Properties of Electrons
Topic: Emission Spectrum
Replies: 4
Views: 23

Re: Emission Spectrum

Emission spectrums represent the energy an electron requires for it to jump up from a lower level to a higher level and back down (when it jumps back down, it releases energy as a photon, which is the line on the spectrum). Where there isn't a line, think of those regions as radiation not having eno...
by Simon Dionson 4I
Sat Oct 19, 2019 4:31 pm
Forum: Properties of Electrons
Topic: parallel spins
Replies: 3
Views: 42

Re: parallel spins

Electron spins have a charge (denoted by + or - 1/2). If they spin in the same direction, they have similar charges and repel each other.
by Simon Dionson 4I
Sat Oct 19, 2019 4:28 pm
Forum: Properties of Electrons
Topic: Photo and electron energy
Replies: 4
Views: 27

Re: Photo and electron energy

The threshold energy (work function) can be thought of as the energy needed to eject an electron from a metal. Any energy radiated that is higher than this will result in a higher kinetic energy. (That's what the equation E = (work function) + E(k) is is relating) In energy levels, electrons have to...
by Simon Dionson 4I
Wed Oct 16, 2019 8:05 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: General question 1B.27
Replies: 4
Views: 42

General question 1B.27

I had a general question on what it means when the velocity is given as
5.00 + or - 5.0 m*s^-1. If we are using p=mv for momentum, how could I relate the + or - interval into ΔP?
by Simon Dionson 4I
Sat Oct 12, 2019 6:11 pm
Forum: DeBroglie Equation
Topic: The Constant, h
Replies: 2
Views: 39

Re: The Constant, h

It's also important to note that Planck's constant, J * S, cancel out the bottom units in wavelength = h/mv (J = kg*m^2*s^-2) (mass = kg) (velocity = m*s^-1)

So wavelength = (kg)(m^2)(s^-2)(s)/(kg)(m^s)(s^-1) = wavelength in meters.

That's how I see it in the context of units like mass and seconds.
by Simon Dionson 4I
Sat Oct 12, 2019 6:00 pm
Forum: DeBroglie Equation
Topic: Circular standing waves
Replies: 4
Views: 25

Circular standing waves

I'm having a hard time understanding what the wavy lines represent. Is it the path of an electron? Or is it representing a wavelength of an electron? Is it representing an electron as a wavelength at a certain energy level? (i.e. n=1, etc.)
by Simon Dionson 4I
Sat Oct 12, 2019 5:49 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation Alternatives?
Replies: 4
Views: 45

Re: Rydberg Equation Alternatives?

Dr. Lavelle's example problem on the 10/9/19 lecture is actually an alternative to way to use the Rydberg equation if both the initial n and final n are known and its possible to use the difference of the calculated energies. Unfortunately for this problem, I'm not sure it's possible since the final...
by Simon Dionson 4I
Sat Oct 12, 2019 5:43 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: En = -hR/n2
Replies: 1
Views: 37

En = -hR/n2

I need some clarifying on the concept of: as n approaches infinity, E = 0. From what I understand it's because the difference between energy levels becomes smaller, but is the electron becoming less bound to the atom also a valid reason why E = 0?
by Simon Dionson 4I
Tue Oct 08, 2019 4:15 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Spectral Lines
Replies: 3
Views: 62

Spectral Lines

1A.11 - This question is asking me about classifying lines to a series (i.e. Balmer or Lyman). Is there a significance of the lines appearing towards certain regions of the light spectrum?
by Simon Dionson 4I
Wed Oct 02, 2019 5:04 pm
Forum: Molarity, Solutions, Dilutions
Topic: HW problem G21
Replies: 3
Views: 40

HW problem G21

How should I approach this problem? Would it make sense to find the molarity of each substance and then collectively add up the concentration (ex. 5M K + 6M K + 3M K + ...) of the ions based on the molecular formulas, or is there another way to do it?
by Simon Dionson 4I
Wed Oct 02, 2019 4:40 pm
Forum: Molarity, Solutions, Dilutions
Topic: E15
Replies: 3
Views: 27

Re: E15

I agree I'm pretty sure the metal in question isn't a sulfide because its molar mass is greater. Maybe there was a typo or something we missed in the problem?
by Simon Dionson 4I
Wed Oct 02, 2019 4:19 pm
Forum: Molarity, Solutions, Dilutions
Topic: G5 Solution?
Replies: 5
Views: 52

Re: G5 Solution?

For some reason in this problem I am always .01 off when I round. Is anybody else having this problem and if so have any advice? I am doing the same process as mentioned above (setting up ratios and solving for x) I did everything in terms of liters and moles. (1mL = .001L) (1mmol = .001mol). For e...
by Simon Dionson 4I
Wed Oct 02, 2019 3:56 pm
Forum: Empirical & Molecular Formulas
Topic: HW problem F9
Replies: 8
Views: 85

Re: HW problem F9

gbernal1C wrote:What do you mean atom ratio?

The problem asks me to express "In what atom ratios are the atoms present in vanillin?". I believe that refers to how much atoms of C, H, and O are there in a ratio.
by Simon Dionson 4I
Wed Oct 02, 2019 3:49 pm
Forum: Empirical & Molecular Formulas
Topic: HW problem F9
Replies: 8
Views: 85

HW problem F9

After finding the molar ratio, would it be inaccurate to express the atom ratio in the same whole numbers as the molar ratio? My thought process would be as if the atoms cancel out if put in a ratio and only the whole numbers from the molar ratio would remain.
by Simon Dionson 4I
Wed Oct 02, 2019 3:38 pm
Forum: Empirical & Molecular Formulas
Topic: Homework problem E1
Replies: 9
Views: 91

Re: Homework problem E1

I imagined the atoms just as units of lengths rather than actual atoms. Once you convert the mole(s) of Ag to atoms w/ Avogadro's number, you'll basically have half of the actual length of the chain. The atoms' diameter rather than radius has to be accounted for, so you double the amount you calcula...

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