You know the half-life equation for a second-order reaction is: t1/2 = 1 / k [A]o
Therefore, after finding k, you can use the integrated rate law 1/[A] = kt + 1/[A]o for a second-order reaction to find t.
Search found 67 matches
- Tue Mar 12, 2019 12:46 am
- Forum: Second Order Reactions
- Topic: Homework, 6th edition, 15.35
- Replies: 3
- Views: 408
- Tue Mar 12, 2019 12:44 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Graphing the Reactions Profiles
- Replies: 2
- Views: 300
Re: Graphing the Reactions Profiles
Yes I think we would need to know. In my discussion section, we went over a question that included labelling the reaction profile so I'd assume it's important! Also, it's good practice to see if you understand the theory behind each of the symbols and what they mean.
- Tue Mar 12, 2019 12:43 am
- Forum: Zero Order Reactions
- Topic: zero order in rate law
- Replies: 7
- Views: 1250
Re: zero order in rate law
Just be sure to know that while the reactant is still in the overall reaction equation, when you write out the rate law, it would be [A]^0 (assuming the reaction is zero order with respect to A) - which equals 1, therefore you wouldn't need to include it in the rate law when you're writing it out.
- Mon Mar 04, 2019 11:33 am
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Study Advice
- Replies: 73
- Views: 7202
Re: Study Advice
Hi! Personally I go to the review sessions (I found Lyndon's midterm review session extremely helpful) and do the step-up session worksheets that are posted on Chemistry Community. There's a lot of resources like maths advice on Dr. Lavelle's website so they're good for clarifying things we don't co...
- Mon Mar 04, 2019 11:32 am
- Forum: Administrative Questions and Class Announcements
- Topic: Discussion about Test questions
- Replies: 5
- Views: 667
Re: Discussion about Test questions
Yep, it's fine though it might help when everyone's gotten their tests back by the end of the week to compare answers and concepts that are unclear!
- Mon Mar 04, 2019 11:21 am
- Forum: Administrative Questions and Class Announcements
- Topic: Week 9 HW
- Replies: 6
- Views: 669
Re: Week 9 HW
Test 2 was on electrochem up till the Nernst equation, so I assume that if you do problems about the Nernst equation and after it, it should be fine? I'm not sure though.
- Tue Feb 26, 2019 10:36 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 2 6th Edition Questions
- Replies: 1
- Views: 292
Test 2 6th Edition Questions
Hi! Does anyone know what questions the electrochemistry portion of Test 2 will go up to for the 6th Edition? So what homework problem number for chapter 14.
- Tue Feb 26, 2019 9:41 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Equations to use
- Replies: 2
- Views: 262
Re: Equations to use
If the problem asks you about different temperatures, for example, and you had to find ∆H and ∆S in the previous parts, then you would use ∆G = ∆H - T∆S. Otherwise, if they give you the values for ∆Gf for the products and reactants, you would use the other equation instead.
- Tue Feb 26, 2019 9:40 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Writing Balanced Equations for Galvanic Cells (14.11 part d sixth edition)
- Replies: 3
- Views: 400
Re: Writing Balanced Equations for Galvanic Cells (14.11 part d sixth edition)
To add onto what the user above said, what to remember is that because it's reduction, you add on electrons onto the left side of the equation.
- Tue Feb 26, 2019 9:39 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Standard Reduction Potential of Cathodes and Anodes
- Replies: 1
- Views: 217
Re: Standard Reduction Potential of Cathodes and Anodes
I would assume these values would be given in any exam questions. In the book, it should be in the appendix tables or given in the question in order for you to actually solve it.
- Wed Feb 20, 2019 12:54 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Question 1A
- Replies: 3
- Views: 407
Re: Midterm Question 1A
Thanks! I thought that Dr. Lavelle said didn't round anything until the end of the question/the final answer though? Especially since the question asked wasn't specifically telling us to find Qp.
- Wed Feb 20, 2019 12:37 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Question 1A
- Replies: 3
- Views: 407
Midterm Question 1A
Hi! For question 1A about Q and Kp, why does Q have to be rounded to 1sf (in the midterm solutions it's 2 x 10^-2) even though it's just working out to the final answer?
- Mon Feb 18, 2019 4:47 pm
- Forum: Student Social/Study Group
- Topic: Best Midterm Review
- Replies: 7
- Views: 768
Re: Best Midterm Review
I personally found Lyndon's midterm review extremely useful - but it's more useful if you attempt his questions beforehand so you're not looking at it for the first time during the session. Also, the UA worksheets are super helpful and Dr. Lavelle's homework problems!
- Mon Feb 18, 2019 4:46 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Delta G vs. Delta G (degree sign)
- Replies: 4
- Views: 2697
Re: Delta G vs. Delta G (degree sign)
Just to add on, if there's a º to something, i.e. ∆Gº or ∆Hº or ∆Sº, it always refers to "under standard conditions" so you would already know T = 298 K and P = 1 atm.
- Mon Feb 18, 2019 4:44 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Calculating Gibbs Free Energy Equations
- Replies: 2
- Views: 321
Re: Calculating Gibbs Free Energy Equations
I think you can use both, and they should give similar (but not necessarily the same) answers. Since you've already found ∆H and ∆S, then it would make sense to use the ∆G = ∆H - T∆S equation.
- Tue Feb 12, 2019 12:14 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: hess law equations
- Replies: 3
- Views: 364
Re: hess law equations
I think that if the equations are more difficult than combustion reactions (where it's just reacting with O2), Dr. Lavelle should give us the equation in the midterm.
- Tue Feb 12, 2019 12:13 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Isochoric vs isometric
- Replies: 4
- Views: 2525
Re: Isochoric vs isometric
They're just different names for the same process, i.e. a constant volume process. Like the user above mentioned, just make sure to understand the differences between isochoric, isothermal, and isobaric processes.
- Tue Feb 12, 2019 12:10 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Extensive vs Intensive
- Replies: 5
- Views: 571
Re: Extensive vs Intensive
In Lyndon's review session, he also pointed out that while heat capacity is an extensive property, specific heat capacity and molar heat capacity are both intensive properties.
- Thu Feb 07, 2019 8:16 am
- Forum: Administrative Questions and Class Announcements
- Topic: Week 5 Homework
- Replies: 3
- Views: 357
Week 5 Homework
Hi! Just wondering which chapters/topics we are allowed to do questions on for our homework - are we allowed to do both thermochemistry and thermodynamics?
- Tue Feb 05, 2019 9:54 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Open vs Closed Systems
- Replies: 4
- Views: 517
Re: Open vs Closed Systems
An important distinction is between closed and isolated systems also, because the bomb calorimeter example seems to come up a lot in class so maybe this is an idea that we need to understand really well. The bomb calorimeter would be closed instead of isolated, as it allows heat to be exchanged and ...
- Tue Feb 05, 2019 9:51 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Midterm
- Replies: 12
- Views: 2160
Re: Midterm
What I usually do for midterm revision is do all the homework problems and Step Up session worksheets and go over my lecture notes if there's a concept that I don't understand - I think this is super important because you can basically do any question once you fully understand a concept!
- Tue Feb 05, 2019 9:50 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Material on Midterm?
- Replies: 9
- Views: 876
Re: Material on Midterm?
In the book (6th edition), the exercise questions are split up into topics so you can do all the questions up to the end of the "Entropy" section and before the "Gibbs Free Energy" section, I believe.
- Mon Jan 28, 2019 9:54 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Le Chatelier's Principle
- Replies: 3
- Views: 560
Re: Le Chatelier's Principle
We just need to know how changing temperature, pressure (and thus volume), and concentration would affect the reaction at equilibrium, i.e. how it shifts equilibrium position or the equilibrium constant (if applicable).
- Mon Jan 28, 2019 9:52 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Memorizing bond enthalpies
- Replies: 5
- Views: 641
Re: Memorizing bond enthalpies
Dr. Lavelle mentioned in class (I think) that we would be given a table of bond enthalpies for everything we need to know - though like what others said, it would be useful to memorise the more common ones!
- Mon Jan 28, 2019 9:51 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Breaking Bonds
- Replies: 4
- Views: 379
Re: Breaking Bonds
Dr. Lavelle drew out the Lewis structures of both the products and reactants and highlighted which bonds were added/broken. Though, it would be helpful to do the longer calculation of all the bonds just to check also!
- Mon Jan 21, 2019 4:35 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: 5% rule
- Replies: 12
- Views: 21803
Re: 5% rule
When calculating the concentration of a reactant or product and given that Kc is less than 10^-3, you can disregard the x if it's something like "0.50-x" and approximate it to 0.50 only. When you get your final result, you then use the 5% rule to see if it is a valid approximation.
- Mon Jan 21, 2019 4:32 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kp vs Kc
- Replies: 7
- Views: 770
Re: Kp vs Kc
To add to this, the question would usually give you either concentration values or partial pressure values and when given one or the other, you would know whether to use Kc or Kp.
- Mon Jan 21, 2019 4:31 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Strong and Weak Acids
- Replies: 3
- Views: 329
Re: Strong and Weak Acids
Weak acids don't fully dissociate in solution, so there is a lower concentration of H+ ion in solution. However for strong acids that fully dissociate, there are more H+ ions in solution which makes the solution more acidic and hence, have a lower pH value as compared to weak acids.
- Wed Jan 16, 2019 9:06 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Ice table coefficients [ENDORSED]
- Replies: 6
- Views: 963
Re: Ice table coefficients [ENDORSED]
For all coefficients in the ICE table, you would follow the stoichiometric coefficients. I think Dr. Lavelle also explained an example in class which used +2x or -2x also.
- Wed Jan 16, 2019 9:05 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Tricks for ICE tables
- Replies: 5
- Views: 511
Re: Tricks for ICE tables
I just think of using ICE tables whenever I see a question mention weak acids or bases, when you need to calculate equilibrium concentrations of anything, or when they give you the equilibrium constant.
- Wed Jan 16, 2019 9:03 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Concentration less than 10^-7
- Replies: 4
- Views: 341
Re: Concentration less than 10^-7
If the hydronium ion concentration is less than 10^-7, e.g. 10^-9, the solution is considered neutral; a solution producing such a small amount of hydronium ions, which doesn't really affect the pH (hence why it's neutral). Autoprotolysis generates 10^-7 molL^-1 of hydronium ions.
- Thu Jan 10, 2019 11:34 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K, Kc and Kp
- Replies: 8
- Views: 604
Re: K, Kc and Kp
If you're referring specifically to homework questions, I believe most of them will say specifically which K/Kc/Kp they want.
- Thu Jan 10, 2019 11:26 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: When to use Kp or Kc
- Replies: 3
- Views: 174
Re: When to use Kp or Kc
I also thought that you only use Kp if all the the reactants and products in the reaction are gases, but usually they specify whether they want you to use Kp or Kc in the textbook homework questions so I assume Dr. Lavelle will do the same on his tests also.
- Thu Jan 10, 2019 11:24 pm
- Forum: General Science Questions
- Topic: Chem 20A to Chem 14B
- Replies: 3
- Views: 807
Re: Chem 20A to Chem 14B
Hi! I think it's not possible to switch from 14A to 20A, but the other way round is totally fine. You'll be able to catch up on anything we've done so far and to be honest, you probably won't need to catch up on much anyways!
- Tue Dec 04, 2018 12:14 pm
- Forum: Lewis Structures
- Topic: Elements that break the octet rule
- Replies: 6
- Views: 853
Re: Elements that break the octet rule
Just remember that if the element can have access to the d-orbital, then it will be able to have an expanded octet as electrons can 'go' into that orbital.
- Tue Dec 04, 2018 12:13 pm
- Forum: Naming
- Topic: Ligand Names
- Replies: 3
- Views: 429
Re: Ligand Names
Another good one to remember is that H2O is aqua when naming compounds. I think Dr. Lavelle also mentioned how, for compounds like CN-, you can use either cyano or cyanido.
- Tue Dec 04, 2018 12:06 pm
- Forum: Administrative Questions and Class Announcements
- Topic: About the test
- Replies: 8
- Views: 1078
Re: About the test
On Dr. Lavelle's website, he said "Questions will come from the Homework and Online Assessments." and "Final exam covers everything in the Syllabus." - everything is fair game. Also, there's some things we learnt later on in the course that we wouldn't be able to do without knowi...
- Tue Nov 27, 2018 10:12 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 9 Test
- Replies: 6
- Views: 676
Re: Week 9 Test
For VSEPR, just be sure to memorise all the names, bond angles, etc., and be sure you know how to draw Lewis structures (because this is normally how you figure out the rest of the info). For bond lengths and strengths, I think the only thing you need to remember is that the shorter the bond, the st...
- Tue Nov 27, 2018 10:09 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 3 material
- Replies: 3
- Views: 505
Re: Test 3 material
Dr. Lavelle's website says: Test 3 covers: End of Bonding from 3.12 (6 Ed.) and from 2D (7 Ed.); and all of Molecular Shape and Structure (see Syllabus and Outlines for details).
Coordination compounds will not be tested!
Coordination compounds will not be tested!
- Tue Nov 27, 2018 10:06 pm
- Forum: Bond Lengths & Energies
- Topic: Bond Length (Chapter 3.16 of 6th Edition)
- Replies: 1
- Views: 378
Re: Bond Length (Chapter 3.16 of 6th Edition)
I think that multiple bonds will always be shorter than single bonds, no matter which elements are involved - i.e. if the elements are the same or different. This is because the more bonds there are, the more electrons that are shared between the atoms, and hence the stronger the bond.
- Mon Nov 19, 2018 10:56 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular shape on test
- Replies: 5
- Views: 417
Re: Molecular shape on test
While we won't be required to draw any 3D shapes of molecules, we will be required to know the shapes, bond angles, hybridisation, and how to draw the Lewis structures of molecules. If you start from drawing the Lewis structure, you can get everything else from VSEPR theory so you're good!
- Mon Nov 19, 2018 10:54 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Thanksgiving week
- Replies: 10
- Views: 1388
Re: Thanksgiving week
The user above is right^. My TA emailed us saying that while there is discussion tomorrow, we would not need to hand in homework until week 9. I guess this is for fairness so everyone hands homework in the same week!
- Mon Nov 19, 2018 10:53 pm
- Forum: Bond Lengths & Energies
- Topic: VSEPR
- Replies: 6
- Views: 2035
Re: VSEPR
Adding to this post, if you knew the AXE 'formula' of GeF4, you could use that to determine the shape easily also, since all molecules with that particular AXE 'formula' would have the same shape! Therefore from there, you can also get the bond angles.
- Tue Nov 13, 2018 12:50 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: determining VSEPR models
- Replies: 6
- Views: 557
Re: determining VSEPR models
When we are determining the shape of and bond angles in a molecule, we use the VSEPR theory. By figuring out the steric number of the molecule and drawing out the Lewis structure, you can use the number of bonds and lone pairs (i.e. the steric number) to figure out the shape of the molecule. After y...
- Tue Nov 13, 2018 12:46 pm
- Forum: Lewis Structures
- Topic: VSEPR Model
- Replies: 6
- Views: 975
Re: VSEPR Model
VSEPR stands for Valence Shell Electron Pair Repulsion, which should give you an idea of what the theory is for. The principle idea behind this theory is that electron pairs around a central atom will assume a position that keeps them as far apart from each other, as electron pairs and bonds repel o...
- Tue Nov 13, 2018 12:43 pm
- Forum: Administrative Questions and Class Announcements
- Topic: 14B Co-Requisites
- Replies: 4
- Views: 805
Re: 14B Co-Requisites
I think it really depends, because I was once able to enrol in a class I didn't have the pre-requisite or the co-requisite for (I was taking the pre-requisite along with the actual class). If my.ucla lets you enrol and the prof doesn't drop you, then you're good to go. It's just that you'll be much ...
- Thu Nov 08, 2018 10:53 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shape
- Replies: 4
- Views: 298
Re: Molecular Shape
This means you can determine the shape by looking at the number of atoms the central atom bonds to, and also the number of lone pairs of electrons on the central atom. Those are the 2 main factors in determining shape.
- Thu Nov 08, 2018 10:52 pm
- Forum: Ionic & Covalent Bonds
- Topic: Covalent or ionic?
- Replies: 4
- Views: 4139
Re: Covalent or ionic?
Here, the thing to remember is that even though we normally think of ionic bonds as between a non-metal and a metal, as in BeBr2, we have to consider the relative electronegativity of the atoms involved in the bond and the electronegativity difference between them. Usually, the electronegativity dif...
- Thu Nov 08, 2018 10:48 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shape
- Replies: 4
- Views: 298
Re: Molecular Shape
The distinction between the 3 shapes you named are the number of lone pairs on the central atom, as the electron-electron repulsion by the lone pair of electrons will cause the other atoms to shift closer to each other; thus, the number of lone pairs on the central atom affects the shape of the enti...
- Thu Nov 08, 2018 10:45 pm
- Forum: Empirical & Molecular Formulas
- Topic: Empirical Formula Problem Solving
- Replies: 2
- Views: 589
Re: Empirical Formula Problem Solving
If the moles of each atom are basically the same and near an integer value, then you can just go off those to find your empirical formula. If the moles of each atom don't seem to follow any obvious ratio, you'll just have to trial and error different numbers to multiply the mole ratios by to get nea...
- Sat Nov 03, 2018 10:55 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Topics 6th Edition
- Replies: 2
- Views: 165
Re: Midterm Topics 6th Edition
Does this mean things like periodicity trends, i.e. electronegativity trends down a group and across a period, won't be tested because that's section 3.12 in the 6th edition of the textbook?
- Sat Nov 03, 2018 1:18 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Topics 6th Edition
- Replies: 2
- Views: 165
Midterm Topics 6th Edition
Dr. Lavelle said that "All material covered in Fundamentals, Quantum, Bonding to end of 3.11 (6 Ed.) and to end of 2C (7 Ed.)"
For the 6th edition, does this mean up to question 11 in chapter 3? I'm kinda confused because I feel like we've learnt the content for questions past question 11!
For the 6th edition, does this mean up to question 11 in chapter 3? I'm kinda confused because I feel like we've learnt the content for questions past question 11!
- Thu Nov 01, 2018 5:28 pm
- Forum: Resonance Structures
- Topic: Purpose of Resonance Hybrids
- Replies: 4
- Views: 451
Re: Purpose of Resonance Hybrids
Resonance hybrids are just the 'sum' of resonance structures one can have for that molecule. As such, the benzene resonance hybrid would only be valid for benzene itself. Other molecules and ions that have several resonance structures can have resonance hybrids too, like the carbonate ion.
- Thu Nov 01, 2018 5:26 pm
- Forum: Trends in The Periodic Table
- Topic: Ionization Energy
- Replies: 3
- Views: 295
Re: Ionization Energy
I don't think we're expected to list the exact ionisation energies in our answers unless we're given them in a table or something. I would assume not because we're only given the basic periodic table in our tests anyways! Just as long as you get the order of elements right.
- Thu Nov 01, 2018 11:17 am
- Forum: Ionic & Covalent Bonds
- Topic: Finding out the likely ion that forms
- Replies: 2
- Views: 250
Re: Finding out the likely ion that forms
I think it's hard to figure out what ions form from the transition metals, so for example copper can form 1+, 2+, 3+, etc. ions. I don't think we'd need to know the ions that the transition metals would form for the test other than the really simple ones? All we need to know is that the electron is ...
- Sat Oct 27, 2018 12:57 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm
- Replies: 7
- Views: 766
Re: Midterm
So Dr. Lavelle mentioned that he would have several important announcements on Monday, so I'd assume he'd be giving us information about the midterm then. I'd recommend starting reviewing everything we've done so far, though I'm not sure if we have time to go through the entirety of chemical bonds b...
- Sat Oct 27, 2018 12:55 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Quantum Numbers
- Replies: 5
- Views: 529
Re: Quantum Numbers
I don't think you would need to know exactly which electron is +1/2 or -1/2; just know that the electrons in the same sub-shell must have opposite spin so one of them must be +1/2 and the other -1/2.
- Sat Oct 27, 2018 12:54 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: s,p,d,f
- Replies: 8
- Views: 959
Re: s,p,d,f
This is because the 4s sub-shells are of a lower energy than the 3d ones so that's why the electrons fill the 4s ones up first.
- Sat Oct 20, 2018 1:03 pm
- Forum: Properties of Electrons
- Topic: Units for Problem #1.25 (6th Edition) [ENDORSED]
- Replies: 1
- Views: 261
Re: Units for Problem #1.25 (6th Edition) [ENDORSED]
ms-1 is metres per second, so a measurement for the speed/velocity of something, while ms is usually milliseconds, which is a measurement for time.
Js is joules multiplied by a second, so a measurement for the action of a system over time, while J is just joules, which is a measurement for energy.
Js is joules multiplied by a second, so a measurement for the action of a system over time, while J is just joules, which is a measurement for energy.
- Sat Oct 20, 2018 12:58 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Effective Nuclear Charge
- Replies: 2
- Views: 291
Re: Effective Nuclear Charge
Effective nuclear charge is basically the attraction the valence electrons around the nucleus feel from it, so what Dr. Lavelle is saying is that the inner electrons 'shield' the amount of attraction the outer electrons feel from the nucleus, hence why it feels a lower electrostatic attraction.
- Sat Oct 20, 2018 11:31 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Test 2 Material
- Replies: 9
- Views: 688
Re: Test 2 Material
I think Dr. Lavelle said that everything from The Quantum World could be tested?
- Tue Oct 09, 2018 10:03 pm
- Forum: Properties of Light
- Topic: Homework Problem 1A.9
- Replies: 2
- Views: 191
Re: Homework Problem 1A.9
If the wave has frequency 300Hz, you can use wavelength = speed of light/frequency to find the wavelength. To calculate energy, you can use energy = Planck's constant x frequency.
- Tue Oct 09, 2018 10:00 pm
- Forum: Properties of Light
- Topic: Relevancy of light to Chemistry
- Replies: 1
- Views: 79
Re: Relevancy of light to Chemistry
Hi! I'm going to guess that you need to first understand the properties of light before you can fully understand the nature of an electron (through understanding how the photoelectric effect works), and subsequently the nature of an atom.
- Tue Oct 09, 2018 9:59 pm
- Forum: Properties of Light
- Topic: Determining the strength of a wave
- Replies: 1
- Views: 108
Re: Determining the strength of a wave
You could look at either of the three to distinguish between different 'types' of waves. I think looking at the wavelength is the easiest, but whatever method you prefer works too!
- Tue Oct 02, 2018 3:45 pm
- Forum: Empirical & Molecular Formulas
- Topic: Rounding
- Replies: 6
- Views: 639
Re: Rounding
If it's something large like 2.38, or as long as it's not very near the whole number, I think you have to find another number to multiply it by. So if it's like 1.01 or 4.99 then it's fine to treat it as 1 and 5 respectively, but if it's 1.2 or 4.8 then you should definitely find another number to m...
- Tue Oct 02, 2018 3:43 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Find concentration of ions given more than one solute
- Replies: 2
- Views: 406
Find concentration of ions given more than one solute
A solution is prepared by dissolving 0.500 g of KCl, 0.500 g of K2S, and 0.500 g of K3PO4 in 500. mL of water. What is the concentration in the final solution of (a) potassium ions; (b) sulfide ions? I know how to do these questions when it's only one solute, but since there's three solutes here how...
- Tue Oct 02, 2018 3:40 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Would it be acceptable to use the term concentration (C) for molarity (M) of a solution?
- Replies: 3
- Views: 378
Re: Would it be acceptable to use the term concentration (C) for molarity (M) of a solution?
Hi! I think concentration and molarity and basically the same meaning and you can use both of them, but while concentration is more general as the measurement of a certain quantity of solute in a certain unit of solution, molarity specifies that it's a measure of the number of moles of solute per li...