Search found 103 matches
- Sat Mar 14, 2020 6:26 pm
- Forum: Balancing Redox Reactions
- Topic: Pt in Cell Diagram
- Replies: 14
- Views: 847
Pt in Cell Diagram
When do we use Pt in a cell diagram?
- Fri Mar 13, 2020 10:35 pm
- Forum: First Order Reactions
- Topic: size
- Replies: 6
- Views: 482
Re: size
It's possible given that it would be able to come into contact with more at one time, but for this class I'm pretty sure just the stoichiometric coefficients matter.
- Fri Mar 13, 2020 10:34 pm
- Forum: First Order Reactions
- Topic: Half Life
- Replies: 13
- Views: 785
Re: Half Life
Half lives are useful for lots of real world applications. If asked for in a question it would ask for it explicitly and the equations should be on the equation sheet.
- Fri Mar 13, 2020 10:31 pm
- Forum: First Order Reactions
- Topic: rate constants
- Replies: 30
- Views: 1285
Re: rate constants
Rate constants are always positive because they are based off time and concentrations which are always positive.
- Fri Mar 13, 2020 12:36 pm
- Forum: Student Social/Study Group
- Topic: final?
- Replies: 7
- Views: 626
Re: final?
I had the same question, hopefully it isn't too complicated. If it's take home I'm assuming we have to take pictures and submit that way? I'm not sure.
- Fri Mar 13, 2020 11:18 am
- Forum: *Identifying Primary, Secondary, Tertiary, Quaternary Carbons, Hydrogens, Nitrogens
- Topic: Will the Final for 14B have Identification?
- Replies: 9
- Views: 5586
Re: Will the Final for 14B have Identification?
He never went over it in class and the topic has an asterisk next to it meaning we don't need to know this.
- Fri Mar 06, 2020 12:11 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Finding Q
- Replies: 7
- Views: 521
Re: Finding Q
Q is anode/cathode usually. You can write out the full reaction equation to verify on a case to case basis.
- Fri Mar 06, 2020 12:09 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Nernst
- Replies: 10
- Views: 693
Re: Nernst
You can use either, the equation sheet lists both so whichever you are most comfortable using is best.
- Fri Mar 06, 2020 12:06 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Cell potential
- Replies: 6
- Views: 477
Re: Cell potential
Adding water will decrease the concentration of everyone else, changing the value of Q which changes cell potential.
- Fri Mar 06, 2020 12:01 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Calculating ln Q
- Replies: 20
- Views: 1387
Re: Calculating ln Q
Q is the concentration of product divided by the concentration of reactant. [product]/[reactant]. Lots of questions will give you the concentrations and you'll be able to solve from there.
- Fri Mar 06, 2020 12:00 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: E° vs E
- Replies: 7
- Views: 465
E° vs E
What's the difference between these two?
- Fri Feb 28, 2020 12:59 am
- Forum: Balancing Redox Reactions
- Topic: 6K. 5b
- Replies: 3
- Views: 294
Re: 6K. 5b
The equations should be as follows:
12OH- + Br2 → 2BrO3- + 6H2O + 10e-
5 x (Br2 + 2e- → 2Br-)
I'm not sure where you got the H from when you did your calculations, maybe you forgot that this was in a basic solution? You use H2O and OH- to balance the H on each side.
12OH- + Br2 → 2BrO3- + 6H2O + 10e-
5 x (Br2 + 2e- → 2Br-)
I'm not sure where you got the H from when you did your calculations, maybe you forgot that this was in a basic solution? You use H2O and OH- to balance the H on each side.
- Fri Feb 28, 2020 12:54 am
- Forum: Balancing Redox Reactions
- Topic: How to tell if its being reduced or oxidized
- Replies: 15
- Views: 1814
Re: How to tell if its being reduced or oxidized
You have to look at the charge of Mn, not the entire compound. In this case, Mn goes from +7 to +2 and is being reduced.
- Thu Feb 27, 2020 8:56 pm
- Forum: Balancing Redox Reactions
- Topic: homework 6K.3
- Replies: 1
- Views: 154
Re: homework 6K.3
I think it's supposed to be Cl2 -> Cl-. I ran into that problem as well but the answer book shows Cl- and I got the right answer doing this.
- Thu Feb 27, 2020 8:55 pm
- Forum: Balancing Redox Reactions
- Topic: 6K. 5a)
- Replies: 5
- Views: 361
Re: 6K. 5a)
Because it's a basic solution, in order to add more H to one side you need to add H2O to that side and OH- to the other, resulting in one more H per H2O molecule on that side while leaving the O balanced.
- Thu Feb 27, 2020 8:00 pm
- Forum: Balancing Redox Reactions
- Topic: 6k3d
- Replies: 3
- Views: 214
Re: 6k3d
I saw this and thought the same thing and I think you're right. The answer key has Cl- in it while the question itself does not.
- Thu Feb 20, 2020 6:59 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: galvanic cell structure
- Replies: 8
- Views: 354
Re: galvanic cell structure
Anodes are more negative and cathodes are more positive, so the electrons naturally go from anode to cathode. Cathodes get reduced and anodes get oxidized.
- Thu Feb 20, 2020 6:57 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Galvanic Cells
- Replies: 8
- Views: 436
Galvanic Cells
What is the purpose of galvanic cells? Is it just to do work on something or is there more than that?
- Thu Feb 20, 2020 6:55 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: cell diagram
- Replies: 4
- Views: 309
Re: cell diagram
So the order of a cell diagram would be solid|gas|aqueous || aqueous|gas|solid. The two lines in the middle represent the salt bridge and the left side represents the anode and the right side represents the cathode. A cell bridge is just another way to represent the transfer of electrons from an an...
- Thu Feb 20, 2020 6:53 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: salt bridge
- Replies: 5
- Views: 295
Re: salt bridge
I think that's the main thing that we need to know about salt bridges, but you should probably also know how to recognize a salt bridge in a cell diagram.
- Thu Feb 20, 2020 6:50 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Purpose of Salt Bridge
- Replies: 12
- Views: 750
Re: Purpose of Salt Bridge
When electrons move, the salt bridge helps balance the charges of the two solutions.
- Sat Feb 15, 2020 3:08 am
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: 4I.9
- Replies: 3
- Views: 315
Re: 4I.9
ΔS is a state function, so they are the same either way. In irreversible however, ΔSsurr=0.
- Sat Feb 15, 2020 3:06 am
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: P1/P2
- Replies: 10
- Views: 1129
Re: P1/P2
Pressure and volume always have an inverse relationship, so it's P1/P2 instead of vice versa.
- Sat Feb 15, 2020 3:05 am
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Irreversible, Adiabatic
- Replies: 3
- Views: 266
Re: Irreversible, Adiabatic
For the surroundings it's 0, the system is W=-PDeltaV I believe. I'm not sure about the second part of your question though, sorry about that.
- Sat Feb 15, 2020 3:01 am
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Delta S
- Replies: 4
- Views: 369
Re: Delta S
For reversible, the reaction is able to go in the reverse direction afterwards which means work has to be done on it by the surroundings to return, or at least that's how I think of it, which means that ΔSsys=-ΔSsurr.
- Sat Feb 15, 2020 2:59 am
- Forum: Calculating Work of Expansion
- Topic: Reversible vs Irreversible
- Replies: 13
- Views: 815
Re: Reversible vs Irreversible
For reversible, delta S of the system is equal to -delta S of the surroundings.
- Thu Feb 06, 2020 8:09 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: 4A.7
- Replies: 2
- Views: 151
Re: 4A.7
You can think of this as two parts, first heating up the kettle, then heating up the water. You just need to add the two values you get for each part to get the final answer.
- Thu Feb 06, 2020 8:07 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Equations
- Replies: 4
- Views: 245
Re: Equations
The equations we need will be on the equations and constants sheet given to us for exams.
- Thu Feb 06, 2020 8:06 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Work done on or by the system
- Replies: 4
- Views: 305
Re: Work done on or by the system
If the system is doing work, it is losing energy, so it is negative. Think of it with yourself as the system, if you open a door you are transferring energy to the door, losing energy yourself (-).
- Thu Feb 06, 2020 8:03 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Delta U equals zero
- Replies: 7
- Views: 296
Re: Delta U equals zero
Considering the first law equation, work and heat would have to equal 0. For an isothermal process, heat is 0, so if there is a reaction that is isothermal that does no work, delta U should be 0.
- Thu Feb 06, 2020 7:59 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: 4B.5 Conversion
- Replies: 6
- Views: 362
Re: 4B.5 Conversion
1 Torr = 0.001316 atm, so you can convert to atm by multiplying 750 by 0.001316, giving 0.987 atm.
- Thu Jan 30, 2020 8:07 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: adiabatic systems
- Replies: 10
- Views: 919
Re: adiabatic systems
Adiabatic means there is no heat exchange, however there can already be heat within the system.
- Thu Jan 30, 2020 8:06 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Heat Supplied to a system
- Replies: 6
- Views: 411
Re: Heat Supplied to a system
Think of this problem as having two parts: first you heat up the copper, then the water. You add up the change in energy for both of them to find the total.
- Thu Jan 30, 2020 8:05 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Increasing energy in an open system
- Replies: 7
- Views: 233
Re: Increasing energy in an open system
Increasing energy in an open system can be done by adding or removing a substance, heating or cooling the system, doing work on the system or vice versa.
- Thu Jan 30, 2020 8:03 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Isolated Systems
- Replies: 5
- Views: 240
Re: Isolated Systems
With an isolated system you can still observe changes happening within without interruption or influence from outside the system.
- Thu Jan 30, 2020 8:02 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: 4A.1
- Replies: 12
- Views: 449
Re: 4A.1
Isolated systems cannot exchange energy with their surroundings. Think of a thermos retaining heat, it counts as an isolated system because the energy transfer from within to outside is negligible.
- Thu Jan 30, 2020 8:00 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: 4A.3 part c
- Replies: 4
- Views: 227
Re: 4A.3 part c
My solution manual says 28J, so I think you may have misread something.
- Thu Jan 30, 2020 7:59 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: 4a.1
- Replies: 3
- Views: 184
Re: 4a.1
When I first did this problem I thought that a) would be closed since it can't be completely isolated, but it's close enough to completely isolated to count.
- Thu Jan 30, 2020 7:58 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: 4A.7
- Replies: 3
- Views: 91
Re: 4A.7
Think of it as two problems, heating up the copper and then heating up the water. You add the two together to get the total.
- Thu Jan 30, 2020 7:57 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Isolated// Energy
- Replies: 11
- Views: 523
Re: Isolated// Energy
There can be reactions that happen within the isolated system, but no energy can leave or enter the system.
- Thu Jan 30, 2020 7:56 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Closed and Isolated
- Replies: 5
- Views: 221
Re: Closed and Isolated
I don't think there's a way for something to be completely isolated, but if it's close enough the difference is negligible.
- Thu Jan 16, 2020 10:47 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: acidity and basicity constant
- Replies: 4
- Views: 181
Re: acidity and basicity constant
If they're the same then why do we have different names for them? Just to clarify?
- Thu Jan 16, 2020 10:46 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Solids and Equilibrium
- Replies: 9
- Views: 252
Re: Solids and Equilibrium
They don't affect either because they are pure and don't change in reactions.
- Thu Jan 16, 2020 10:44 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: H3O+
- Replies: 4
- Views: 116
Re: H3O+
H+ and H30+ are interchangable for us I believe. H+ is just H30+ without the water.
- Thu Jan 16, 2020 10:42 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5 percent rule
- Replies: 10
- Views: 471
Re: 5 percent rule
The percent protonization or deprotonization needs to be less than 5% for the x value to be valid; it makes it acceptable to use approximations.
- Thu Jan 16, 2020 10:33 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kc & Kp
- Replies: 12
- Views: 261
Re: Kc & Kp
I think we use Kp when all of the reactants and products are gases.
- Fri Jan 10, 2020 10:49 pm
- Forum: Ideal Gases
- Topic: pressure [ENDORSED]
- Replies: 13
- Views: 984
Re: pressure [ENDORSED]
I think if you increase the amount of gas or increase the temperature it also increases temperature.
- Fri Jan 10, 2020 10:47 pm
- Forum: Ideal Gases
- Topic: Solving for K (coefficients)
- Replies: 11
- Views: 472
Re: Solving for K (coefficients)
Just make sure the coefficients for specific molecules remain on the same molecules as a power when calculating K.
- Fri Jan 10, 2020 10:44 pm
- Forum: Ideal Gases
- Topic: R in PV=nRT
- Replies: 34
- Views: 5631
Re: R in PV=nRT
It's a constant and should be given with any exams so I don't think we need to worry too much about it.
- Fri Jan 10, 2020 10:42 pm
- Forum: Ideal Gases
- Topic: Ideal Gas Law
- Replies: 6
- Views: 166
Re: Ideal Gas Law
If we are given partial pressure but need concentration or vice versa it helps us convert between the two.
- Fri Jan 10, 2020 10:42 pm
- Forum: Ideal Gases
- Topic: K value
- Replies: 14
- Views: 1029
Re: K value
Large K value means that the reaction shifts to the right, small K value means the opposite.
- Sun Dec 08, 2019 12:06 am
- Forum: Administrative Questions and Class Announcements
- Topic: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
- Replies: 115
- Views: 11818
Re: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
how do you get 33b?
- Sat Dec 07, 2019 3:16 pm
- Forum: Polyprotic Acids & Bases
- Topic: Calculating pH of polyprotic acid
- Replies: 2
- Views: 285
Calculating pH of polyprotic acid
The textbook says that we only use the first deprotonation equilibrium for polyprotic acids except for sulfuric acid, so do we just calculate the pH of these acids just as we would for monoprotic acids?
- Fri Dec 06, 2019 12:38 pm
- Forum: Naming
- Topic: Name --> formula
- Replies: 2
- Views: 205
Re: Name --> formula
I don't think this is explicitly stated anywhere but I would do alphabetical order just in case, don't wanna lose free points on the final
- Fri Dec 06, 2019 12:37 pm
- Forum: Naming
- Topic: Adding -ate to end of transition metal
- Replies: 2
- Views: 188
Re: Adding -ate to end of transition metal
Yes, for example cobalt is cobalate and copper is ferrate.
Re: naming
Don't use the prefixes when listing in alphabetical order
- Fri Dec 06, 2019 12:03 pm
- Forum: Naming
- Topic: Writing formulas for coordination compounds
- Replies: 2
- Views: 168
Re: Writing formulas for coordination compounds
I think it would say if there was an overall charge, indicated by brackets
- Fri Dec 06, 2019 12:01 pm
- Forum: Naming
- Topic: Cyanido vs cyano
- Replies: 5
- Views: 296
Re: Cyanido vs cyano
They are interchangable and should give the same points on a test
- Fri Dec 06, 2019 11:54 am
- Forum: Naming
- Topic: Using alternate Greek prefixes
- Replies: 2
- Views: 99
Re: Using alternate Greek prefixes
There's a table in the textbook that shows the most common polydendate ligands
Re: (diqaua)
I wasn't sure on this one either, but I think it has to do with being polydendate? I'm not sure though.
- Fri Dec 06, 2019 11:27 am
- Forum: Naming
- Topic: Adding -ate
- Replies: 2
- Views: 167
Re: Adding -ate
Cuprate for copper I believe
- Fri Dec 06, 2019 11:23 am
- Forum: Naming
- Topic: Polyatomic ions
- Replies: 2
- Views: 187
Re: Polyatomic ions
It's probably a good idea to know them just in case, you never know what's gonna be on the final
9C.1 a
Why do we use "cyano" instead of "cyanido?" Does it have to do with the bonds on the central atom for hexacyanoferrate(II)?
- Fri Nov 22, 2019 3:06 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone Pairs
- Replies: 8
- Views: 543
Re: Lone Pairs
Lone pairs are equatorial usually, but for something like AX4E2 they are axial so they are farthest apart.
- Fri Nov 22, 2019 3:04 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Shape of Diatomic Molecules
- Replies: 5
- Views: 409
Re: Shape of Diatomic Molecules
They should all be linear, two atoms together can only make a straight line between.
- Fri Nov 22, 2019 3:02 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Which shape
- Replies: 6
- Views: 401
Re: Which shape
Dipoles have to cancel out or it will be polar. I think it helps to look for symmetry in molecules and atoms within molecules to find if something is polar.
- Fri Nov 22, 2019 3:00 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Test 2
- Replies: 14
- Views: 658
Re: Test 2
Does anyone have any advice about studying intermolecular forces?
- Wed Nov 20, 2019 8:31 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Test 2
- Replies: 1
- Views: 152
Test 2
What do we need to know for test 2? Everything covered after the midterm?
- Thu Nov 14, 2019 7:41 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: format of test
- Replies: 5
- Views: 240
Re: format of test
I wouldn't imagine it being any different from previous tests.
- Thu Nov 14, 2019 7:41 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2E.7
- Replies: 3
- Views: 193
Re: 2E.7
Bond angles are something you have to memorize, and I'm pretty sure the angles are determined by electron densities, not atomic attraction, but I'm not positive there.
- Thu Nov 14, 2019 7:38 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Trigonal Pyramid vs Trigonal Planar
- Replies: 6
- Views: 429
Re: Trigonal Pyramid vs Trigonal Planar
If there is a lone pair on the central atom, it makes the overall shape trigonal pyramidal, if there are no lone pairs on the central atom it's planar pretty sure.
- Thu Nov 14, 2019 7:37 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2E.7
- Replies: 2
- Views: 209
Re: 2E.7
I think the answer is 1 because the bonds are the same angle, but I'm not sure.
- Thu Nov 14, 2019 7:35 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Homework 2E.1
- Replies: 4
- Views: 139
Re: Homework 2E.1
When drawing the lewis structure, make sure to remember formal charges!
- Thu Nov 07, 2019 5:25 pm
- Forum: Lewis Structures
- Topic: Expanded Octet
- Replies: 10
- Views: 449
Re: Expanded Octet
Element in the third period or further can have an expanded octet because the electrons and go into the d-orbital.
- Thu Nov 07, 2019 5:25 pm
- Forum: Lewis Structures
- Topic: Exceptions for the octet rule
- Replies: 5
- Views: 354
Re: Exceptions for the octet rule
Anything in the third period or past that because they have an empty d shell that can be expanded into
- Thu Nov 07, 2019 5:23 pm
- Forum: Lewis Structures
- Topic: Lewis structure
- Replies: 5
- Views: 219
Re: Lewis structure
O is more electronegative than P so it receives the negative charge, and you want the charges to be spread out, not on one atom usually
- Thu Nov 07, 2019 5:19 pm
- Forum: Lewis Structures
- Topic: Expanded Octet
- Replies: 4
- Views: 200
Re: Expanded Octet
Yes, this is testable with calculating the formal charges of the atoms
- Thu Nov 07, 2019 4:32 pm
- Forum: Lewis Structures
- Topic: Octet rule exceptions?
- Replies: 4
- Views: 267
Re: Octet rule exceptions?
I think it's the first elements where they simply don't have enough electrons to fill an octet and anything after the third period where expanded octets can occur.
- Thu Oct 31, 2019 8:13 pm
- Forum: Electronegativity
- Topic: What does electronegativity affect?
- Replies: 2
- Views: 127
What does electronegativity affect?
I understand the trends on the periodic table, but what does a high electronegativity mean?
- Thu Oct 31, 2019 8:11 pm
- Forum: Ionic & Covalent Bonds
- Topic: 2A.21
- Replies: 4
- Views: 150
Re: 2A.21
All of them have no unpaired electrons because the shells are filled, but there are some cases where 3d is filled with 8 electrons, leaving 2 unpaired electrons due to Hund's rule I believe.
- Thu Oct 31, 2019 8:08 pm
- Forum: Ionic & Covalent Bonds
- Topic: 2A 5
- Replies: 5
- Views: 117
Re: 2A 5
For Ga+3 I believe the answer is [Ar]3d^10 because the 3d shell fills before the 4s does. You write the "largest" noble gas filled with electrons in brackets followed by the extra electrons.
- Thu Oct 31, 2019 8:04 pm
- Forum: Ionic & Covalent Bonds
- Topic: 2A 19b
- Replies: 3
- Views: 136
Re: 2A 19b
The question asks about how many unpaired electrons Sn^4+ has, which is 0 because the entire 4d shell is full.
- Thu Oct 31, 2019 8:01 pm
- Forum: Ionic & Covalent Bonds
- Topic: 2A 1
- Replies: 5
- Views: 238
Re: 2A 1
Mn has a ground state of [Ar]3d^7, hence the 7 valence electrons while Sb is [Kr]4d^10 5s^2 5p^3 with 5 valence electrons in the higher energy state.
- Thu Oct 24, 2019 4:41 pm
- Forum: Lewis Structures
- Topic: Ion lewis structure
- Replies: 9
- Views: 334
Re: Ion lewis structure
It doesn't matter, just make sure you have the right amount of them.
- Thu Oct 24, 2019 4:34 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic v.covalent bonds
- Replies: 7
- Views: 308
Re: Ionic v.covalent bonds
Yeah you're right, I think it also has to do with whether or not the electrons are shared between the atoms or just taken from one to the other as well.
- Thu Oct 24, 2019 4:29 pm
- Forum: Ionic & Covalent Bonds
- Topic: valence electrons
- Replies: 6
- Views: 395
Re: valence electrons
I'm not sure to be honest, but I think it has to do with 4s, 4p, and 4d being filled, leaving 5s and 5p electrons.
- Thu Oct 24, 2019 4:27 pm
- Forum: Ionic & Covalent Bonds
- Topic: Octet Rule
- Replies: 6
- Views: 183
Re: Octet Rule
They can't form an octet and never would in nature because they would never receive electrons for that, they are stable at lower values.
- Thu Oct 24, 2019 4:25 pm
- Forum: Ionic & Covalent Bonds
- Topic: What's the difference between valence electrons and the valence of an atom?
- Replies: 3
- Views: 349
Re: What's the difference between valence electrons and the valence of an atom?
I think that means the number of covalent bonds an atom has, which is tightly related to the amount of valence electrons it has.
- Thu Oct 17, 2019 6:59 pm
- Forum: Properties of Light
- Topic: Constant for Speed of Light
- Replies: 14
- Views: 530
Re: Constant for Speed of Light
2.998x10^8 is most accurate, but for some solutions in the manual it uses even more precise numbers. I think for the tests we're given the constants to use though so we should all be fine!
- Thu Oct 17, 2019 6:58 pm
- Forum: Properties of Light
- Topic: Speed of light
- Replies: 13
- Views: 310
Re: Speed of light
Any EMR has the same speed, we just call it the speed of light (c)
- Thu Oct 17, 2019 6:57 pm
- Forum: Properties of Light
- Topic: The units for each equation we're using?
- Replies: 4
- Views: 210
Re: The units for each equation we're using?
On the class website there's a link that says Constants and Equations, that should help you :)
- Thu Oct 17, 2019 6:36 pm
- Forum: Properties of Light
- Topic: 1B #9
- Replies: 5
- Views: 124
Re: 1B #9
64 total Joules are emitted over 2 seconds, and we have all the information we need we need to find E=ch/(wavelength). After you find E, you can divide 64 by E to find out how many photons there are, and then you can divide that number by Avogadro's number, 6.022x10^23 to find the moles of photons.
- Thu Oct 17, 2019 6:17 pm
- Forum: Photoelectric Effect
- Topic: HW 1B.5
- Replies: 8
- Views: 314
Re: HW 1B.5
So do we have to convert keV to J for all problems or is it specific to this one?
- Thu Oct 10, 2019 5:20 pm
- Forum: Properties of Light
- Topic: 1.A.3 Hw Help
- Replies: 3
- Views: 112
Re: 1.A.3 Hw Help
You can eliminate a b and d through the process of elimination. I first looked at b but that's the opposite of the right answer. When the frequency decreases, the wavelength increases, so c is the correct answer as the change in the electrical field is lower at any point when the wavelength increases.
- Thu Oct 10, 2019 5:09 pm
- Forum: Properties of Light
- Topic: Problem 1A, #15
- Replies: 3
- Views: 112
Re: Problem 1A, #15
From figure 1a.10 you know that the line in question is part of the Lyman series. From this you know that n1 is 1, and from there you find out that 1/n2^2 is around .111 or 1/9.
- Thu Oct 10, 2019 4:44 pm
- Forum: Properties of Light
- Topic: HW 1A.11
- Replies: 1
- Views: 102
HW 1A.11
In the spectrum of atomic hydrogen, several lines are generally classified together as belonging to a series (for example, Balmer series or Lyman series, as shown in Fig. 1A.10). What is common to the lines within a series that makes grouping them together logical? I'm pretty sure the answer is beca...
- Thu Oct 10, 2019 4:40 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Test 1 [ENDORSED]
- Replies: 107
- Views: 16826
Re: Test 1 [ENDORSED]
Do we have to memorize equations or are we given a list of equations?
- Thu Oct 10, 2019 4:17 pm
- Forum: Properties of Light
- Topic: Question 1.A.3
- Replies: 4
- Views: 246
Re: Question 1.A.3
As I first did this problem I immediately looked for a "the wavelength increases" answer, but there was none. I also used the process of elimination to eliminate a b and d, leaving only c as the possible answer. From the correct answer you can learn that higher wavelength results in less c...
- Thu Oct 03, 2019 5:54 pm
- Forum: Balancing Chemical Reactions
- Topic: Fractioned Chemical Equations?
- Replies: 5
- Views: 286
Re: Fractioned Chemical Equations?
From my understanding, yes you are correct. Using whole numbers just makes things easier to use or read for lab experiments or simple calculations.
- Thu Oct 03, 2019 5:46 pm
- Forum: SI Units, Unit Conversions
- Topic: E.15
- Replies: 3
- Views: 149
E.15
The molar mass of the metal hydroxide M(OH)₂ is 74.10 g.mol. What is the molar mass of the sulfide of this metal?
What does it mean by the sulfide of this metal?
What does it mean by the sulfide of this metal?