Search found 79 matches

by Malia Shitabata 1F
Sun Jan 19, 2020 3:09 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6B.11 part a ii
Replies: 1
Views: 5

6B.11 part a ii

A student added solid Na2O to a volumetric flask of volume 200.0 mL which was then filled with water resulting in 200.0 mL of NaOH solution. Then 5.00 mL of the solution was transferred to another volumetric flask and diluted to 500.0 mL. The pH of the diluted solution is 13.25. What is the molar co...
by Malia Shitabata 1F
Sun Jan 19, 2020 3:02 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Volume and pressure
Replies: 4
Views: 15

Re: Volume and pressure

If you increase the pressure, the volume decreases. You can think about it in terms of the ideal gas law PV=nRT.
by Malia Shitabata 1F
Sat Jan 18, 2020 11:29 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6B.9
Replies: 3
Views: 16

6B.9

For the fill in the table, the first row with 1.50 mol/L given for [H3O+], I got a negative pH when I did pH=-log(1.50) but the solution manual says the pH is positive. Did I do something wrong or is that a typo?
by Malia Shitabata 1F
Sat Jan 18, 2020 1:39 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: pH sig figs
Replies: 5
Views: 32

pH sig figs

When you have pOH and you're trying to find the pH should the pH have the same number of decimal places as the pOH? For example, if your pOH is 2.735 would you subtract from 14 or 14.000 or something in between? Because I feel like if you subtract from 14 and round based on decimal places then it ca...
by Malia Shitabata 1F
Tue Jan 14, 2020 2:43 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6D.3
Replies: 1
Views: 25

6D.3

When the pH of 0.10 M HClO2 (aq) was measured, it was found to be 1.2. What are the values of Ka and pKa of chlorous acid? I got the molarity of H3O+ through the pH but the solution manual says [H3O+]=[ClO2-]. If everything is in a 1:1 mole ratio, why isn't [ClO2-] 0.10 M like the HClO2? Also when p...
by Malia Shitabata 1F
Mon Jan 13, 2020 11:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6B.3
Replies: 2
Views: 16

Re: 6B.3

For part a since you're just doing the initial pH it's just based on the molarity so you do -log(0.025). For part b, find the moles using the molarity and the initial volume of 200.0 and then divide by the volume you actually ended up using to find the molarity of the used solution. Then find -log o...
by Malia Shitabata 1F
Mon Jan 13, 2020 7:06 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kw and H3O/OH concentrations
Replies: 5
Views: 14

Kw and H3O/OH concentrations

For water, is [H3O+] always equal to [OH-]? Because in class Professor Lavelle was saying they're both 1.0x10^-7 which is why Kw is 1.0x10^-14, but the book also mentions the see saw behavior when there's more H3O+, OH- concentration will decrease.
by Malia Shitabata 1F
Mon Jan 13, 2020 2:59 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Autoprotolysis
Replies: 6
Views: 22

Autoprotolysis

Does autoprotolysis only happen with water or can it be other molecules as well?
by Malia Shitabata 1F
Thu Jan 09, 2020 6:42 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5I.17
Replies: 3
Views: 24

Re: 5I.17

I'm not sure how you got x=0.0114, but if you plug in all the values into the K c ratio so that it's 1.00*10 -5 =(2x) 2 /((0.114-x)(0.114-x)) and solve for x using the quadratic formula, you should get x=1.8*10 -4 . I did 1.00x10^-5=(2x)^2/(0.114)^2 instead of (0.114-x)(0.114-x) for the denominator...
by Malia Shitabata 1F
Thu Jan 09, 2020 6:05 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5I.17
Replies: 3
Views: 24

5I.17

The equilibrium constant Kc for the reaction N2(g) + O2 (g) \rightleftharpoons 2NO (g) at 1200ºC is 1.00x10^-5. Calculate the equilibrium molar concentrations of NO, N2, and O2 in a reaction vessel of volume 1.00 L that initially held 0.114 mol N2 and 0.114 mol O2. I set up the ICE table with all th...
by Malia Shitabata 1F
Thu Jan 09, 2020 12:23 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5I.33
Replies: 2
Views: 30

5I.33

A sample of ammonium carbamate, NH4(NH2CO2) of mass 25.0 g was placed in an evacuated flask of volume 0.250 L and kept at 25ºC. At equilibrium, 17.4 mg of CO2 was present. What is the value of Kc for the decomposition of ammonium carbamate into ammonia and carbon dioxide? The reaction is NH4(NH2CO2)...
by Malia Shitabata 1F
Tue Jan 07, 2020 2:34 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Writing expression for K
Replies: 5
Views: 51

Re: Writing expression for K

You can use partial pressures when all the reactants and products of a reaction are in the gas phase and when the units are in the gas phase (bar, atm, mmHg, Torr, etc). You normally use concentrations when other phases other than the gas phase are involved in the reaction, and you can use PV=nRT t...
by Malia Shitabata 1F
Mon Jan 06, 2020 5:27 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Effect on the equilibrium constant
Replies: 2
Views: 34

Effect on the equilibrium constant

The textbook says the equilibrium constant value is only changed by varying the temperature. How come changing other physical conditions like pressure or volume don't affect the equilibrium constant?
by Malia Shitabata 1F
Mon Jan 06, 2020 5:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Writing expression for K
Replies: 5
Views: 51

Writing expression for K

When a question asks you to write an expression for K, how do you know when to use Px or [X]?
by Malia Shitabata 1F
Sat Dec 07, 2019 5:55 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: pKA values
Replies: 4
Views: 38

Re: pKA values

pKa = -log[Ka] and it's the weak acid equilibrium constant. It's important to know so you can determine which acid is stronger/weaker when given its value. Ka and pKa have an inverse relationship. So a strong acid would have a high Ka value but a low pKa value. Conversely, a weak acid would have a l...
by Malia Shitabata 1F
Sat Dec 07, 2019 5:50 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Pka and Ph
Replies: 2
Views: 26

Re: Pka and Ph

pH equals pKa at the equivalence point, but I don't think that necessarily means the solution is neutral. When pH is less than pKa, the conditions are acidic enough for an acid to be protonated as HA.
by Malia Shitabata 1F
Sat Dec 07, 2019 5:30 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Ka for strong/weak acids
Replies: 2
Views: 25

Ka for strong/weak acids

Is Ka given if it's a strong or a weak acid? Because for some reason on one of my notes I wrote Ka is never given for a weak acid, but on another I wrote if it's given it's for a weak acid and now I'm not sure which one is correct.
by Malia Shitabata 1F
Sat Dec 07, 2019 1:22 pm
Forum: *Stereochemistry
Topic: Various Isomers
Replies: 1
Views: 30

Various Isomers

How do stereoisomers differ from geometrical isomers? The definitions sound very similar.
by Malia Shitabata 1F
Fri Dec 06, 2019 3:42 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Resonance
Replies: 3
Views: 26

Re: Resonance

So does this increase acidity strength or decrease it?
by Malia Shitabata 1F
Fri Dec 06, 2019 3:28 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Resonance
Replies: 3
Views: 26

Resonance

Resonance spreads the delocalized charge over more atoms and increases stability. Does this mean that if a molecule has resonance it's a weaker atom since the bonds will be more stable and take more energy to break?
by Malia Shitabata 1F
Fri Dec 06, 2019 3:11 pm
Forum: Biological Examples
Topic: Porphyrin
Replies: 1
Views: 31

Porphyrin

Porphyrin is characterized by a tentradentate square planar formation of 4 nitrogen atoms. Does the central atom have to be a transition metal or can it be any other element?
by Malia Shitabata 1F
Thu Dec 05, 2019 10:24 pm
Forum: Biological Examples
Topic: Cisplatin bonding in 2 places
Replies: 3
Views: 39

Cisplatin bonding in 2 places

Cisplatin can bond in 2 places because the chlorine atoms are easily displaced. Does this mean it chelates when it bonds with DNA?
by Malia Shitabata 1F
Wed Dec 04, 2019 9:46 pm
Forum: Hybridization
Topic: Pi bonds
Replies: 1
Views: 24

Pi bonds

Can someone explain the relationship between hybridization and pi bonds?
by Malia Shitabata 1F
Wed Dec 04, 2019 9:45 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Ka and Kb
Replies: 3
Views: 29

Ka and Kb

For polyprotic acids, Ka1 is always greater than Ka2 and the first step is always the stronger acid. Does the same go for Kb? Would Kb1 be greater than Kb2 and the first step indicate the stronger base?
by Malia Shitabata 1F
Wed Dec 04, 2019 9:42 pm
Forum: Naming
Topic: Cation Order
Replies: 1
Views: 15

Cation Order

If we're given the name of a coordination compound and asked to write the formula for it, does it mater what order we write the cations in? Because how would you be able to tell unless we're supposed to write them alphabetically?
by Malia Shitabata 1F
Sat Nov 30, 2019 10:07 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate
Replies: 3
Views: 16

Polydentate

So a ligand is polydentate if it can bond multiple regions to the central atom. So does this mean it's based off of the lone pairs or is it something else?
by Malia Shitabata 1F
Sat Nov 30, 2019 3:26 pm
Forum: Naming
Topic: Iron
Replies: 1
Views: 18

Iron

How do you know when to name a complex with iron in it as iron or ferrate? Because in the toolbox 9C.1 in the textbook, [FeCl(OH2)5]^+ is pentaaquachloridoiron(II) ion while [Fe(CN)6]^4- is hexacyanidoferrate(II) ion but both cases have iron as the central atom.
by Malia Shitabata 1F
Sat Nov 30, 2019 2:10 pm
Forum: Naming
Topic: Water
Replies: 1
Views: 28

Water

When do we use aqua vs dihydrogen/dihydrate when H2O is present in a molecule?
by Malia Shitabata 1F
Sat Nov 30, 2019 1:56 pm
Forum: Naming
Topic: -ate
Replies: 1
Views: 19

-ate

If a complex compound has a negative charge, we are supposed to add ate to the ending of the metal name. Do we do the same if it's a positive charge or do we not add anything?
by Malia Shitabata 1F
Fri Nov 29, 2019 5:12 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: triple equal sign
Replies: 2
Views: 28

triple equal sign

I'm not really sure what to call it but what does the equal sign but with three lines mean? I wrote that pKA=-log[KA] in my notes and that p=-log except that for the p equation the equal sign had 3 lines. Was this just a typo or does it have a significance?
by Malia Shitabata 1F
Fri Nov 22, 2019 12:23 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Transplatin
Replies: 3
Views: 23

Transplatin

I understand why cisplatin is an effective chemotherapy drug, but can someone reexplain why transplatin isn't? I don't think I copied it down correctly in lecture.
by Malia Shitabata 1F
Wed Nov 20, 2019 1:22 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligands
Replies: 4
Views: 39

Ligands

Can ligands be a central atom if the central atom has a lone pair or does it always have to be a surrounding atom the central atom is bonded to?
by Malia Shitabata 1F
Wed Nov 20, 2019 1:19 pm
Forum: Biological Examples
Topic: Cisplatin
Replies: 4
Views: 46

Re: Cisplatin

So because it is a cis molecule the two chlorine atoms are on the same side of the cisplatin molecule. As a result, when one chlorine bonds the other can be displaced so the compound can be bound in 2 places which makes the bonds stronger. This blocks DNA replication from occurring so cell division ...
by Malia Shitabata 1F
Wed Nov 20, 2019 1:16 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Compound Arrangement
Replies: 2
Views: 21

Compound Arrangement

For the [NiCl2(NH3)4] example from class why are some of the ammonia atoms written backwards how do we know when to write them backwards?
by Malia Shitabata 1F
Tue Nov 19, 2019 1:40 pm
Forum: Hybridization
Topic: Degenerate Orbitals
Replies: 1
Views: 22

Degenerate Orbitals

In the problem that we did in class with methane CH4 the sp^3 hybridization was made using degenerate orbitals. Do we always use degenerate orbitals when doing hybridization?
by Malia Shitabata 1F
Sun Nov 17, 2019 9:12 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Electronic arrangement vs molecular shape
Replies: 4
Views: 14

Re: Electronic arrangement vs molecular shape

So would the actual bond angle be closer to the shape obtained from the electronic arrangement or the molecular shape?
by Malia Shitabata 1F
Sun Nov 17, 2019 6:59 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Electronic arrangement vs molecular shape
Replies: 4
Views: 14

Electronic arrangement vs molecular shape

I'm a little confused what the difference between electronic arrangement and molecular shape is since VSEPR rule 3 says only positions of atoms count toward molecular shape. Can someone explain this in simpler terms?
by Malia Shitabata 1F
Sun Nov 17, 2019 5:53 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizable vs polarizing power
Replies: 5
Views: 46

Polarizable vs polarizing power

Is polarizability only used to describe anions and polarizing power only for cations? And if so, does this imply that anions have no polarizing power and cations are not polarizable?
by Malia Shitabata 1F
Sun Nov 17, 2019 5:01 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lewis Structure Representation
Replies: 1
Views: 16

Lewis Structure Representation

For the Lewis structure representation using the dashed and thick lines to indicate which plane each atom is in, is there any way to indicate double and triple bonds or is it only for single bonds? Also is there a name for this model?
by Malia Shitabata 1F
Wed Nov 13, 2019 10:10 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 2
Views: 24

Bond Angles

For a molecule with a trigonal planar shape, how do we know if it's 120º, less than 120º, or 109.5º?
by Malia Shitabata 1F
Wed Nov 13, 2019 10:06 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E #5
Replies: 4
Views: 42

2E #5

What is the shape of a ClO2+ ion and what is the expected bond angle?

The solution manual says it is trigonal planar, but how come it's not a linear shape if Cl is only bonded to two other atoms? And if it's trigonal planar, why would the bond angles be slightly less than 120º?
by Malia Shitabata 1F
Wed Nov 06, 2019 2:19 pm
Forum: Properties of Light
Topic: Rydberg Equation
Replies: 5
Views: 78

Re: Rydberg Equation

I think we need to know that the energy level starts from n=1 for Lyman series(UV region) and it starts from n=2 for Balmer series(visible region, 700nm-400nm). If a higher frequency is associated with greater energy then why is Balmer n=2 even though visible light has a lower frequency than ultrav...
by Malia Shitabata 1F
Wed Nov 06, 2019 12:16 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 2A #21
Replies: 1
Views: 27

2A #21

Give the ground state electron configuration and number of unpaired electrons expected for each of the following ions: Ag+ The answer in the solutions manual was [Kr]4d^{10} but the answer I got was [Kr]4d^8 because I thought you would subtract the electron since the charge is positive? But the elec...
by Malia Shitabata 1F
Tue Nov 05, 2019 7:35 pm
Forum: Coordinate Covalent Bonds
Topic: Coordinate vs polar covalent
Replies: 6
Views: 75

Coordinate vs polar covalent

How does a coordinate covalent bond differ from a polar covalent bond?
by Malia Shitabata 1F
Tue Nov 05, 2019 7:33 pm
Forum: Properties of Light
Topic: Rydberg Equation
Replies: 5
Views: 78

Rydberg Equation

Do we have to understand the Balmer/Lyman series in relation to n and the Rydberg equation or should we just know which portion of the electromagnetic spectrum it corresponds to?
by Malia Shitabata 1F
Tue Nov 05, 2019 7:30 pm
Forum: Properties of Electrons
Topic: Mass of an electron
Replies: 9
Views: 61

Mass of an electron

Do we have to memorize the mass of an electron since it's a constant or will it be given on the reference sheet?
by Malia Shitabata 1F
Sun Nov 03, 2019 7:07 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge Stability
Replies: 3
Views: 37

Re: Formal Charge Stability

Also when assigning formal charge values, if there is a negative value it is most stable if it goes on the more electronegative atom.
by Malia Shitabata 1F
Sat Nov 02, 2019 7:40 pm
Forum: Electronegativity
Topic: Figuring it out without the trend?
Replies: 4
Views: 34

Re: Figuring it out without the trend?

Electronegativity is how likely an atom is to attract an electron into its orbital so you can also think of it in terms of the attractive forces between the protons and electrons and how easy it is for an electron to complete an orbital and make an atom stable.
by Malia Shitabata 1F
Sat Nov 02, 2019 7:36 pm
Forum: Electronegativity
Topic: which bond
Replies: 4
Views: 35

Re: which bond

If we're being super specific, if the electronegativity difference is <2 it is a polar covalent bond and if the electronegativity difference is 0 it is a covalent bond. This designates if it's a bond shared between two of the same element ie C-C (covalent) or different elements ie C-H (polar covalen...
by Malia Shitabata 1F
Sat Nov 02, 2019 2:42 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Degenerate orbitals
Replies: 4
Views: 39

Degenerate orbitals

Can somebody explain what degenerate orbitals are? They mentioned it during the review session yesterday, but I was a little confused
by Malia Shitabata 1F
Tue Oct 29, 2019 10:53 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 2A #5
Replies: 4
Views: 24

Re: 2A #5

Thanks! And do we always write the 3 level before the 4 because I thought it was only for chromium and copper?
by Malia Shitabata 1F
Tue Oct 29, 2019 9:59 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 2A #5
Replies: 4
Views: 24

2A #5

Give the ground state electron configuration for Cu+ ion. The solutions manual says the answer is [Ar]3d^10 but I wrote out the full electron configuration as 1s^22s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{8} which still has the same number of electrons. Am I still right even though they end on two different...
by Malia Shitabata 1F
Fri Oct 25, 2019 5:00 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?

Other elements can also exceed the octet rule by being satisfied with more than 8 electrons such as the elements in the third row or higher
by Malia Shitabata 1F
Thu Oct 24, 2019 12:29 pm
Forum: Ionic & Covalent Bonds
Topic: octet rule
Replies: 6
Views: 89

Re: octet rule

Boron also tends to not follow the octet rule since it can be stable with only 6 valence electrons.
by Malia Shitabata 1F
Thu Oct 24, 2019 12:24 pm
Forum: Ionic & Covalent Bonds
Topic: valence
Replies: 3
Views: 52

Re: valence

They might ask what the valency of a certain element is which refers to the number of covalent bonds it can make so for Nitrogen it would be 3
by Malia Shitabata 1F
Thu Oct 24, 2019 12:19 pm
Forum: Octet Exceptions
Topic: Octet Rule
Replies: 6
Views: 48

Re: Octet Rule

I wrote at the end of class after we were drawing Lewis structures that the octet rule holds strictly for C, N, O, F, Ne. Did I mishear or does this mean something different since it doesn't make sense that other elements wouldn't follow the octet rule.
by Malia Shitabata 1F
Tue Oct 22, 2019 2:11 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 1E.25
Replies: 3
Views: 37

Re: 1E.25

(a) The alkali metals are all the metals in Group 1A, belong in the s-block, and have 1 valence electron each. Therefore, depending on which shell the element is in, the configuration will be ns^1. (b) Group 15 elements are in the p-block with 15 valence electrons each, 2 in the s sublevel, 10 in t...
by Malia Shitabata 1F
Sun Oct 20, 2019 5:54 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: 1.B.27
Replies: 1
Views: 30

Re: 1.B.27

You use the Heisenberg uncertainty equation which is \Delta x=h/(2m\Delta v) except h is h bar (I just couldn't find the symbol for it on this platform) so you would use Planck's constant divided by 2pi. Just plug in everything given to solve for delta x which is the uncertainty and use 5.0 ...
by Malia Shitabata 1F
Sun Oct 20, 2019 5:00 pm
Forum: Properties of Light
Topic: Question 1A.15
Replies: 5
Views: 55

Re: Question 1A.15

First you use to calculate the change in energy then you use E=-hR/n^2 to calculate the energy at n=1. Plug those in to the energy equation where change in Energy=final energy-initial energy. Plug the final energy back into Rydberg's equation to solve for n as the final energy level.
by Malia Shitabata 1F
Sun Oct 20, 2019 4:51 pm
Forum: Properties of Light
Topic: HW problem A3
Replies: 2
Views: 28

Re: HW problem A3

I think it relates to the energy since the energy decreases as the frequency decreases and electrons are bound to energies of discrete values; if the energy is lower it has less of a range. You can probably also just explain why the other answers are wrong.
by Malia Shitabata 1F
Sun Oct 20, 2019 1:55 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: h bar
Replies: 3
Views: 38

h bar

I was looking at the examples in the book in Topic 1B and they use the equation \Delta x=h/(2m\Delta v) except the h has a line through it to represent h bar. It seems like it's a constant 1.05457x10^-34 but what exactly does it represent? Because to calculate uncertainty in class we used \D...
by Malia Shitabata 1F
Sat Oct 19, 2019 11:29 pm
Forum: Properties of Electrons
Topic: d vs s orbitals
Replies: 6
Views: 48

d vs s orbitals

Professor Lavelle mentioned writing the d orbital before the s orbital when doing electron configurations, and he used chromium as an example so it was 3d4s. For elements further down in the periodic table like molybdenum which is right below it, it would end in 4d5s but do we still write it as 3d4s...
by Malia Shitabata 1F
Fri Oct 11, 2019 11:18 pm
Forum: Properties of Light
Topic: Question 1B7
Replies: 1
Views: 21

Question 1B7

Sodium vapor lamps, used for public lighting, emit yellow light of wavelength 589 nm. How much energy is emitted by (a) an excited sodium atom when it generates a photon; (b) 5.00 mg of sodium atoms emitting light at this wavelength; (c) 1.00 mol of sodium atoms emitting light at this wavelength? Ca...
by Malia Shitabata 1F
Fri Oct 11, 2019 11:05 pm
Forum: Properties of Light
Topic: Adding formulas
Replies: 5
Views: 38

Re: Adding formulas

It's also the mediator step of which showed the linear momentum of a particle that has wavelike properties
by Malia Shitabata 1F
Fri Oct 11, 2019 5:28 pm
Forum: DeBroglie Equation
Topic: Applying the DeBroglie Equation
Replies: 6
Views: 43

Re: Applying the DeBroglie Equation

The DeBroglie equation can't be applied to light
by Malia Shitabata 1F
Fri Oct 11, 2019 5:27 pm
Forum: DeBroglie Equation
Topic: Electrons in a box
Replies: 2
Views: 21

Re: Electrons in a box

I think it refers to the idea that electrons have quantized energy states in atoms and possibly alludes to the Heisenberg equation since we know its energy will most likely be found in a certain energy level but not its exact position.
by Malia Shitabata 1F
Fri Oct 11, 2019 5:00 pm
Forum: Properties of Light
Topic: Waves/Particles
Replies: 14
Views: 122

Re: Waves/Particles

So the photons are acting as particles when emitted in the photoelectric effect, but I also wrote in my notes that electrons act as waves. Does it acts as both a wave and a particle or did I misunderstand the lecture?
by Malia Shitabata 1F
Fri Oct 11, 2019 4:09 pm
Forum: Properties of Light
Topic: Using the Rydberg Equation in HW 1A.15
Replies: 4
Views: 38

Re: Using the Rydberg Equation in HW 1A.15

You would first use the wavelength you have and find the energy change using E=(hc)/wavelength. Once you have the energy change, use the equation E=(-hR)/n^2 with n=1 to find the energy of the electron at n=1. Once you have the energy change and the energy of the electron at n=1, you can set up thi...
by Malia Shitabata 1F
Sun Oct 06, 2019 4:04 pm
Forum: Molarity, Solutions, Dilutions
Topic: G. 13
Replies: 5
Views: 50

Re: G. 13

You would first find the molarity of the new solution using the equation M1V1=M2V2, then using the equation Molarity = (Moles)/(Volume) find the moles in 100mL. I followed this but I'm not sure it gave the right answer since the solution manual said the concentration should be 0.050 and I got 0.067...
by Malia Shitabata 1F
Sun Oct 06, 2019 3:12 pm
Forum: Molarity, Solutions, Dilutions
Topic: Question G7
Replies: 2
Views: 26

Re: Question G7

Because it's an aqueous solution, water is the only other component besides KNO3. I think we can assume that those are the only two ingredients since they didn't give us anything else to work with and it would be difficult to figure out other mass components based on speculation. Since you have a to...
by Malia Shitabata 1F
Sun Oct 06, 2019 2:56 pm
Forum: Molarity, Solutions, Dilutions
Topic: G5
Replies: 6
Views: 110

G5

"A student prepared a solution of sodium carbonate by adding 2.111 g of the solid to a 250.0 mL volumetric flask and adding water to the mark. Some of the solution was transferred to a buret. What volume should the student transfer into a flask to obtain 2.15 mmol Na+?" I understand that y...
by Malia Shitabata 1F
Thu Oct 03, 2019 12:18 pm
Forum: Balancing Chemical Reactions
Topic: Products of combustion reactions
Replies: 7
Views: 71

Re: Products of combustion reactions

Are they also always in the same physical states ie gas?
by Malia Shitabata 1F
Thu Oct 03, 2019 12:16 am
Forum: Significant Figures
Topic: Rounding Sig Figs
Replies: 4
Views: 46

Re: Rounding Sig Figs

And also remember that conversion factors never count for sig figs. For example if you're using Avogadro's number to convert moles 6.022 x 10^22 you wouldn't use the 4 sig figs from that number for your final answer.
by Malia Shitabata 1F
Thu Oct 03, 2019 12:12 am
Forum: SI Units, Unit Conversions
Topic: Diagnostic test for chem 17 vs 14A
Replies: 5
Views: 70

Re: Diagnostic test for chem 17 vs 14A

At least from the description chem 17 seemed like it was just a repeat of high school chemistry. I think even if you're feeling like you're rusty you will probably do fine in chem 14A. Lavelle said he will go over chemistry topics every time we start a new unit so it's never like we're jumping into ...
by Malia Shitabata 1F
Tue Oct 01, 2019 1:52 pm
Forum: Significant Figures
Topic: Determining how many sig figs to use
Replies: 3
Views: 55

Re: Determining how many sig figs to use

I think for mass percentage compositions it usually rounds to two decimal places. I'm not sure if there's an exact sig fig rule for that.
by Malia Shitabata 1F
Tue Oct 01, 2019 1:47 pm
Forum: Significant Figures
Topic: How Many significant figures to use ?
Replies: 9
Views: 104

Re: How Many significant figures to use ?

Also conversion factors don't count toward sig figs so if you have to convert at some point ie 1000 mg per 1 g, don't round your answer to 1 sig fig if that makes sense
by Malia Shitabata 1F
Tue Oct 01, 2019 1:45 pm
Forum: Significant Figures
Topic: How Many significant figures to use ?
Replies: 9
Views: 104

Re: How Many significant figures to use ?

Usually the significant figures in your answer are based off of the significant figures in the numbers given in the problem. You also usually use the smallest number of sig figs. For example, if the problem gives you 3.40 mol Cl and 17.35 g H, since the lowest number of sig figs is 3 coming from Cl,...
by Malia Shitabata 1F
Tue Oct 01, 2019 1:42 pm
Forum: SI Units, Unit Conversions
Topic: Homework for Week 1
Replies: 16
Views: 257

Re: Homework for Week 1

I thought the homework of the 5 questions per week are turned in during our discussion classes and the online discussion goes toward our lecture grade but isn't something turned in physically. What homework are you referring to that is turned into the lecture on Friday?
by Malia Shitabata 1F
Tue Oct 01, 2019 1:39 pm
Forum: SI Units, Unit Conversions
Topic: Textbook
Replies: 7
Views: 74

Textbook

Should we be bringing our textbook to all lecture/discussion classes? It's pretty bulky (and mine is loose leaf so I don't want to make a mess of all the pages) and we haven't seemed to use it in class so far.

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