## Search found 64 matches

Mon Jan 11, 2021 3:29 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Module 2
Replies: 2
Views: 43

### Re: Module 2

You would set up an ICE table like usual but that 18.3% is allowing you to calculate the equilibrium concentration of BrCl. So once you calculate the molarity of BrCl which is 1.84 x 10^-4M, you multiply it by 0.183 to find the equilibrium concentration. This also gives you the change value which yo...
Mon Jan 11, 2021 3:26 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Textbook problem 5.33
Replies: 3
Views: 25

### Re: Textbook problem 5.33

The question is pretty much showing you a visible representation of the initial reaction and the reaction at equilibrium. Then you would apply Le Chatelier's principle to see which of those factors will result in the second picture, where more product is produced. In this case, only increasing the t...
Mon Jan 11, 2021 3:21 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Textbook problem 5.61
Replies: 3
Views: 22

### Re: Textbook problem 5.61

Compression does mean that the volume decreases and as a result, the pressure increases. You would only look at the amount of gaseous moles on either side, in this case it would be equal at 6 and 6, so the compression would have no effect on the equilibrium.

Hope this helps!
Mon Jan 11, 2021 2:17 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Principle Explanation
Replies: 4
Views: 29

### Re: Principle Explanation

For me, it's helpful to visualize what's happening. So for instance, if more reactant is added, there's a lot of those molecules and the seesaw is unbalanced. So what needs to be done to level it out? You have to consume more reactant to get rid of it and because you're using it up, more product wil...
Mon Jan 11, 2021 2:14 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: ICE Table
Replies: 9
Views: 29

### Re: ICE Table

You put + when that species is being formed aka the product because it's molarity will increase. You subtract whatever species is being consumed, aka the reactants because it's overall molarity will increase. The coefficient in front of x is determined by the stoichiometric coefficients present in t...
Mon Jan 04, 2021 1:12 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: How do you write the K for an equation with heterogeneous equilibria?
Replies: 10
Views: 35

### Re: How do you write the K for an equation with heterogeneous equilibria?

You would only include the aqueous reactants and the gas and aqueous products. Solids are omitted but it otherwise follows the same format as always, the important thing is just knowing what to omit (solids and liquids).

Hope this helps!
Mon Jan 04, 2021 12:42 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Pure substances in equilibrium expressions
Replies: 3
Views: 19

### Re: Pure substances in equilibrium expressions

You don't include solids when solving for K because they don't have concentrations, the volume amount doesn't matter. Liquids in reactions have constant concentrations and since they're not changing it pretty much cancels out on both sides of the reaction and thus isn't included. Solvent are also ne...
Mon Jan 04, 2021 12:38 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K vs. Kc/Kp
Replies: 15
Views: 65

### Re: K vs. Kc/Kp

K refers to Kc or Kp. Kc is used when you're inputting concentrations of the gases. Kp is used when you're inputting the partial pressures of the gases. So the subscript pretty much denotes what type of measurement you're using to calculate the equilibrium constant.

Hope this helps!
Mon Jan 04, 2021 12:36 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5I.27 Textbook Problem
Replies: 3
Views: 26

### Re: 5I.27 Textbook Problem

When I did the calculation for Q,I got 0.5 and so Q wouldn't be equal to a K of 0.56 and since Q would be less than K, the reaction would proceed to the right to form more PCl5. Here's my work for it, maybe try calculating it again? Q = [PCl5]/([PCl3][Cl2]) Q = [1.5mol/0.5L]/([3mol/0.5L][0.5mol/0.5L...
Mon Jan 04, 2021 12:31 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Module 1A True/False question
Replies: 8
Views: 39

### Re: Module 1A True/False question

So part A is true because at equilibrium, the concentrations of reactants and products are constant and therefore the composition of the equilibrium remains constant because concentrations aren't changing. Part B is false increasing the forward reaction rate won't increase the amount of products, it...
Fri Dec 11, 2020 2:35 pm
Forum: Administrative Questions and Class Announcements
Topic: TA Review: Fundamentals - Erin [ENDORSED]
Replies: 1
Views: 151

### Re: TA Review: Fundamentals - Erin[ENDORSED]

Does anyone have the answers to this worksheet so I can check my answers?

Thanks!
Thu Dec 10, 2020 11:03 am
Forum: Determining Molecular Shape (VSEPR)
Topic: TA Review
Replies: 3
Views: 44

### Re: TA Review

Did he ever respond to you because I still haven't heard back
Mon Dec 07, 2020 10:54 am
Forum: Amphoteric Compounds
Topic: Methods to identify whether it's Amphoteric, basic or acidic
Replies: 2
Views: 126

### Re: Methods to identify whether it's Amphoteric, basic or acidic

Usually a compound is acidic if it has an H in front of it (ex: H3PO4, HCl, HBr etc.) because it's easy to tell that the H will be lost as H+ and an anion will be formed. Easy basic compounds to spot are those with OH so the strong bases all have OH (ex: NaOH, KOH, LiOH etc.) because that extra H wi...
Mon Dec 07, 2020 10:51 am
Forum: Amphoteric Compounds
Topic: How to know if a molecule is amphoteric
Replies: 9
Views: 92

### Re: How to know if a molecule is amphoteric

How can we identify if a molecule is amphoteric or not? Other than water being a common one? You would have to see what it forms when you add or take away a H. For example. H2PO4- is another amphoteric compound. To act as a base, it needs another H+ which would make it form H3PO4 which is phosphori...
Mon Dec 07, 2020 10:46 am
Forum: Amphoteric Compounds
Topic: examples
Replies: 3
Views: 154

### Re: examples

Another example of an amphoteric compound is H2PO4- because it can act as a base and gain a H+ to form H3PO4, often with water acting as the acid, or it can lose a H+ to form HPO4- to act as an acid.

Hope this helps!
Mon Dec 07, 2020 10:41 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: electronegativity vs bond length for determining acidity
Replies: 4
Views: 29

### Re: electronegativity vs bond length for determining acidity

Since the bond being broken is the same in both molecules, the O -- H bond, you would either look at resonance which isn't present in this case or electronegativity. This is why HCl is the stronger acid because Cl is more electronegative than Br.

Hope this helps!
Mon Dec 07, 2020 10:39 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Stability of Anions Considering Strengths of ACids
Replies: 4
Views: 26

### Re: Stability of Anions Considering Strengths of ACids

The more stable the resulting anion is, the more likely it is to form and for it to form, the acid must give up the proton or H+. This is why resonance relates to the strength of the acid because resonance makes the anion more stable. Anions can also be stabilized through electron withdrawing atoms,...
Tue Dec 01, 2020 1:19 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Textbook Problem 2E #13
Replies: 3
Views: 60

### Textbook Problem 2E #13

The question asks to draw the Lewis structure, VSEPR formula, molecular shape, and bond angles for each of the following species. For part A, the molecule is I3-, the VSEPR formula says X2E3. I understand that there's no distinguished central atom since they're all iodine but then why is it X2 and n...
Mon Nov 30, 2020 9:07 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligands
Replies: 5
Views: 25

### Re: Ligands

Meghan Krushena 3F wrote:So if all ligands are Lewis bases, does that mean all transitional metals are cations? Or can Lewis base ligands only bond with cation transitional metals?

All transition metals form cations so ligands are Lewis bases that donate an electron pair to a TM cation.

Hope this helps!
Mon Nov 30, 2020 9:05 am
Forum: Shape, Structure, Coordination Number, Ligands
Replies: 2
Views: 25

Dr. Lavelle did mention that pentadentates do exist but they're not as common. Hexadentates are common since compelxes often have octahedral geometry. I don't think it goes past hexadentate but I'm not sure. I am sure 6 sites is more than enough for Chem 14A which is why he only mentioned the common...
Mon Nov 30, 2020 9:02 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: H20 complexes
Replies: 3
Views: 46

### Re: H20 complexes

Electron-rich species I believe just means that it has electron pairs to donate. So I think what Dr. Lavelle meant was that if you add an ionic compound (like KCl) which will disassociate into its ions (K+ and Cl-), the Cl will displace the water molecule and bond to the transition metal instead and...
Mon Nov 30, 2020 8:59 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Number & Resonance Structures
Replies: 2
Views: 27

### Re: Coordination Number & Resonance Structures

Yeah I believe that they're not really related. Since there is a transition metal involved and its a coordinate covalent bond, I think you just need to find the coordination number by counting the number of bonds.

Hope this helps!
Mon Nov 30, 2020 8:57 am
Forum: Naming
Topic: chelating ligand
Replies: 7
Views: 71

### Re: chelating ligand

Chelating ligands are the ligands that can donate more than one lone pair (bidentate, tridentate etc.). A monodentate can only donate one lone pair and therefore cannot form a ring of atoms like the chelating ligands.

Hope this helps!
Mon Nov 23, 2020 4:21 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Ways to remember VSEPR
Replies: 6
Views: 85

### Re: Ways to remember VSEPR

I don't have a great way to remember it so I just remember it conceptually. I know it has to do with valence electrons so that gives me V S and E. Then I say electrons come together but then decide they don't like each other (this isn't conceptually accurate but it's how I remember). The coming toge...
Mon Nov 23, 2020 4:18 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Carbon Double Bond
Replies: 4
Views: 42

### Re: Carbon Double Bond

The inability to rotate applies for all double bonds. This is because every double bond is one sigma and one pi bond. The pi bonds don't allow for rotation of bound molecules because then the bond would break, since the p orbitals are overlapping side by side (Dr. Lavelle's demo with the expo marker...
Mon Nov 23, 2020 12:45 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Why is CH2Cl2 polar?
Replies: 6
Views: 60

### Re: Why is CH2Cl2 polar?

The molecule is polar because of its polar bonds. Cl is much more electronegative than C and therefore the dipoles point towards Cl. They don't cancel out and thus the molecule is polar. You may think they cancel based on the Lewis structure but remember that the angles for tetrahedral are 109.5˚ no...
Mon Nov 23, 2020 12:29 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sapling #8
Replies: 5
Views: 53

### Re: Sapling #8

Yeah I would try changing your answer slightly, maybe there's a typo or something? BeCl2 has two polar bonds with dipoles towards the Cl but they cancel because they're going in the opposite direction so the molecule as a whole is nonpolar. H2O also has two polar bonds and with the dipoles towards t...
Mon Nov 23, 2020 11:46 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Electron shape vs molecular shape
Replies: 4
Views: 23

### Re: Electron shape vs molecular shape

I think you mean electron density... Electron density is described by how many regions of electron density are present (both bonding and lone pairs count as regions of electron density). Molecular shape only relies on the atoms and their positions (aka only the bonding pairs). Sometimes the electron...
Mon Nov 16, 2020 11:29 am
Forum: Bond Lengths & Energies
Topic: LDF Bond Strength
Replies: 11
Views: 86

### Re: LDF Bond Strength

Larger molecules have more electrons that are farther away and thus, less tightly held. Because of this, there are more easily distorted and thus, there is more possibility for them to interact with the other valence electrons of the other atom and form temporary dipoles, making the dispersion force...
Mon Nov 16, 2020 10:56 am
Forum: Resonance Structures
Topic: Total Number of Resonance Structures
Replies: 3
Views: 39

### Re: Total Number of Resonance Structures

You can't tell right off the bat how many resonance structures a molecule has but there are ways to help you out. For example, if a central atom is bonded to 3 identical atoms (ex: SO3) and there is one double bond and two single bonds, you know there will be at least 3 resonance structures since th...
Mon Nov 16, 2020 10:50 am
Forum: Bond Lengths & Energies
Topic: sapling #4
Replies: 3
Views: 29

### Re: sapling #4

I asked my TA about this wording as well and he said not too worry about it too much since they're such ambiguous words and aren't used to scientifically describe bond character. I would just find the average between the single and double bond lengths and determine which the given bond length is clo...
Mon Nov 16, 2020 10:47 am
Forum: Bond Lengths & Energies
Topic: Bond energy equation
Replies: 3
Views: 30

### Re: Bond energy equation

The distance plays a larger role because it's raised to the 6th power and its inversely proportional to the energy, so if the distance increases even by a little, the energy will decrease significantly. The polarizability of the molecules won't have as big of an affect because there are 2 values, so...
Mon Nov 16, 2020 10:38 am
Forum: Bond Lengths & Energies
Topic: F2 Bond Strength
Replies: 6
Views: 48

### Re: F2 Bond Strength

Because F2 molecules are small, they are close together which increases the repulsion between the lone pairs. This increased repulsion makes the bond weaker and hence easier to break.

Hope this helps!
Mon Nov 09, 2020 9:52 pm
Forum: Octet Exceptions
Topic: Aluminum Chloride Structure
Replies: 4
Views: 19

### Re: Aluminum Chloride Structure

When referring to unusual Lewis structures, the book means that they don't need a full octet. All Group 13 elements tend to be electron deficient, but we focus mostly on B and Al in this class because they're more common. Both B and Al like to form 3 instead of 4 bonds. This is because the formal ch...
Mon Nov 09, 2020 9:49 pm
Forum: Octet Exceptions
Topic: Expanded Octets
Replies: 3
Views: 55

### Re: Expanded Octets

I am not 100% sure nor am I sure we will venture that far in 14A but it pretty much follows the same rules. Other common elements you see with expanded octets include Kr and Xe which can go to 6 pairs of electrons.

Hope this helps!
Mon Nov 09, 2020 8:44 pm
Forum: Formal Charge and Oxidation Numbers
Topic: 2.A.3
Replies: 3
Views: 29

### Re: 2.A.3

For an ion, you need to figure out what noble gas element it's trying to be like. So for sulfur with a 2- charge, it's trying to be like argon. So pretty much you would write the ground state electron configuration for argon since you are adding two electrons. So the configuration would be 1s2 2s2 2...
Mon Nov 09, 2020 11:55 am
Forum: Lewis Structures
Topic: Sapling Weeks 5-6 HW Question 3
Replies: 10
Views: 104

### Re: Sapling Weeks 5-6 HW Question 3

I think Sophia made a mistake with the formal charge for phosphorus so I'll just start from the beginning: So phosphite is PO3 with an overall charge of 3-. We would put P in the middle since it has a lower ionization energy. First, we should calculate the total number of valence electrons. In this ...
Mon Nov 09, 2020 11:44 am
Forum: Lewis Structures
Topic: Placement of central atom
Replies: 5
Views: 20

### Re: Placement of central atom

Yes, as a general rule, the atom with the lowest ionization energy and therefore the least electronegative will go in the center. The center atom is also usually the one that there is only one of. So for example in methane (CH4), the carbon would be in the middle because there's one of them, nature ...
Wed Nov 04, 2020 11:12 am
Forum: Resonance Structures
Topic: Expanded Octet Examples
Replies: 5
Views: 49

### Re: Expanded Octet Examples

Anything on the 3rd period or below can technically have an expanded octet but in my experience, the most common ones we deal with in chemistry are sulfur, phosphorus and chlorine. Silicon is another one but is quite uncommon so I wouldn't worry about that one too much. Phosphorus tends to form 5 bo...
Wed Nov 04, 2020 10:02 am
Forum: Resonance Structures
Topic: Resonance for Sulfate Ion
Replies: 3
Views: 30

### Re: Resonance for Sulfate Ion

The main reason for sulfur having an expanded octet is because it's in the 3rd period which means that there are d orbitals available for bonding as well. Any element from period 3 and below can form an expanded octet due to the empty d orbitals available. Since the 3p and 3d levels are close in ene...
Mon Nov 02, 2020 11:44 am
Forum: Formal Charge and Oxidation Numbers
Topic: Why do we use formal charge?
Replies: 14
Views: 114

### Re: Why do we use formal charge?

Formal charge is used to figure out which structure has the lowest energy and hence is the most stable. Many molecules have multiple resonance structures and formal charge is the means which scientists use to determine which structure occurs in nature aka the most stable one. The goal is to get the ...
Mon Nov 02, 2020 10:41 am
Forum: Lewis Structures
Topic: Line in place of paired dots
Replies: 8
Views: 43

### Re: Line in place of paired dots

No, it's pretty universal that a single line indicates a covalent bond where two electrons are being shared so it would be unclear what you meant if you replaced the two dots representing a lone pair with a single line. To reiterate, the two dots indicate a lone pair, which means those electrons are...
Mon Nov 02, 2020 9:25 am
Forum: Ionic & Covalent Bonds
Topic: Differences in structures between ionic and covalent bonds
Replies: 7
Views: 71

### Re: Differences in structures between ionic and covalent bonds

Darren, The reason that ionic bonds are stronger than covalent bonds is that electrons are completely lost or gained, for example Na loses one electron and Cl gains one electron. In covalent bonds, the electrons are shared through electron clouds, so neither atom really possesses that electron, they...
Thu Oct 29, 2020 11:28 am
Forum: Trends in The Periodic Table
Topic: Elements with a low ionization energy
Replies: 6
Views: 62

### Re: Elements with a low ionization energy

A low ionization energy means that the atom will lose an electron quite easily. In nature, what occurs is usually the easiest thing, which means whatever takes the least amount of energy. So if it requires very little energy to remove an electron, electrons will be removed thus forming cations. This...
Wed Oct 28, 2020 10:31 pm
Forum: Einstein Equation
Topic: Textbook Problem 1B.9
Replies: 5
Views: 74

### Re: Textbook Problem 1B.9

This problem is daunting at first but the key is to examine the units that are given and go from there. In this case, the problem tells you that a watt is equivalent to 1 J/s. Therefore you know you need to find something with units in joules, aka energy. So like you said, you would use E = hc / lam...
Tue Oct 27, 2020 1:35 pm
Forum: DeBroglie Equation
Topic: Sapling Week 2-4 HW Question 24
Replies: 11
Views: 125

### Re: Sapling Week 2-4 HW Question 24

I was confused about this too, especially what "continuous" meant. But I think the easiest way to think about it is that there needs to be a whole number of wavelengths. So the 2nd from the top on your right hand column has 2 full wavelengths and the top one on your right column has 4 full...
Mon Oct 26, 2020 2:58 pm
Forum: Photoelectric Effect
Topic: Sapling Problem #6
Replies: 7
Views: 120

### Sapling Problem #6

Question: The electron in a hydrogen atom is excited to the n= 7 shell and emits electromagnetic radiation when returning to lower energy levels. Determine the number of spectral lines that could appear when this electron returns to the lower energy levels, as well as the wavelength range in nanomet...
Mon Oct 26, 2020 10:11 am
Forum: *Shrodinger Equation
Topic: Practice Textbook Problems
Replies: 2
Views: 39

### Re: Practice Textbook Problems

For this problem, the first thing you need to do is find the energy per photon, using E = hc/λ. Once you find the energy per photon, you should calculate the total energy the light is providing in the 2.0s (which would be 64 W or 64 J/s). Then you can divide the total energy (64W) by the energy per ...
Tue Oct 20, 2020 9:52 pm
Forum: Properties of Light
Topic: Textbook Question 1.A.9
Replies: 4
Views: 50

### Re: Textbook Question 1.A.9

For the second row, you should use the equation E = hv to find the frequency (5.0 x 10^14 Hz) and then from there use c = λv to find the wavelength (600 nm after you convert). In the third row, you should again use E = hv which would be E = (3.00 x 10^8 Hz) * (6.626 x 10^-34 Js) to get an energy of ...
Tue Oct 20, 2020 9:04 pm
Forum: Properties of Light
Topic: Relationship between intensity and amplitude
Replies: 3
Views: 47

### Relationship between intensity and amplitude

I always thought that the intensity of light was equal to the amplitude of that light's wavelength. But the textbook (1A.2) says that the intensity is equal to the amplitude squared. I hadn't heard this in lecture or anywhere else, could someone please clarify what their relationship is? Do we need ...
Mon Oct 19, 2020 10:53 am
Forum: Properties of Light
Topic: Difference between E=hv and E=hc/v?
Replies: 9
Views: 91

### Re: Difference between E=hv and E=hc/v?

They are the same equation really, just in the second one the frequency is being substituted by a different formula ( v = c / λ). You use the second/longer version when you need to find the wavelength usually because then you have a variable present in the equation. The longer way to do it would be ...
Mon Oct 19, 2020 10:42 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectroscopy Post-Assessment Question
Replies: 6
Views: 54

### Atomic Spectroscopy Post-Assessment Question

In Online Module #6, one of the questions asked if molecular spectroscopy can be used to identify molecules. I know that the answer is yes but I am confused as to why. Many molecules consist of the same elements (ex: C, H and O), all that varies is the ratio of the elements. Spectroscopy can identif...
Mon Oct 19, 2020 10:40 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectroscopy Assessment question clarification
Replies: 2
Views: 29

### Re: Atomic Spectroscopy Assessment question clarification

This was confusing for me as well. For this problem, what you need to do is divide 1 meter by the number of wavelengths (1,650,763.73) because that's how many wavelengths are there in one meter. Once you find the value of the wavelength (6.06 x 10^-7 m), then you use the equation E = (h * c)/ λ to f...
Wed Oct 14, 2020 11:16 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Energy gaps and specific regions of EM radiation
Replies: 1
Views: 48

### Energy gaps and specific regions of EM radiation

In the lecture, Dr. Lavelle was explaining that for all the lines in the UV region, the energy differences end at n = 1, for visible light it ended at n = 2 and for infrared it ended at n = 3. Is this universal or does it only apply to the hydrogen atom?
Tue Oct 13, 2020 10:56 pm
Forum: Properties of Light
Topic: Photoelectric spectrum
Replies: 24
Views: 163

### Re: Photoelectric spectrum

Like everyone else is saying a general idea of where different types of radiation fall will definitely be useful. Here's a little guide to help you! From long to short wavelength: radio waves --> microwaves --> infrared --> visible light --> UV --> X ray --> gamma rays Within visible light: It goes ...
Tue Oct 13, 2020 10:51 pm
Forum: Properties of Light
Topic: High Frequency = Energy?
Replies: 4
Views: 52

### Re: High Frequency = Energy?

Like Cecilia said, the relationship between frequency and energy can be found in the equation E = hv. Since E (energy) and v (frequency) are on opposite sides of the equal sign, they are directly proportional; if they were on the same side (such as wavelength and frequency are in c = λ * v) they wou...
Mon Oct 12, 2020 10:02 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect original purpose
Replies: 6
Views: 32

### Re: Photoelectric Effect original purpose

The purpose of the experiment was to determine how tightly elements were holding on to their electrons. In other words, it was to determine how much energy was necessary to remove an electron from different metal surfaces. However, the unexpected result that they found was that the wave model does n...
Mon Oct 12, 2020 11:02 am
Forum: Properties of Light
Topic: Quantized
Replies: 11
Views: 65

### Re: Quantized

When an equation is quantized, the variables must be discrete values (1,2,3 etc.). This is unlike a continuous function where the variables can be decimals such as in F = m * a, where the values of mass and acceleration can pretty much be any number. In other words, the simplest way to think about i...
Mon Oct 12, 2020 10:53 am
Forum: Properties of Light
Topic: Quanta and Photons
Replies: 19
Views: 172

### Re: Quanta and Photons

The smallest transferable unit he is referring to is equal to one water molecule in this case. In his example, he said the diameter of the nozzle continues to reduce until only water molecules come out. Then he exaplined that in this instance, you saw a jump of 1 on the scale and you saw up to a jum...
Wed Oct 07, 2020 10:54 am
Forum: Limiting Reactant Calculations
Topic: Limiting reactants
Replies: 8
Views: 80

### Re: Limiting reactants

Yes, it would mean there's no limiting reactant, there are sufficient amounts for each reactant. In that case, you could choose either reactant [I would recommend doing the reactant that has the smallest ratio or 1:1 if possible, less math = less silly mistakes :) ] to find the moles of the desired ...
Wed Oct 07, 2020 10:29 am
Forum: Limiting Reactant Calculations
Topic: Limiting Reagents
Replies: 10
Views: 117

### Re: Limiting Reagents

A limiting reactant and a limiting reagent are the same thing. It's just two different terms describing the same concept, they're synonymous. They both are the reactant/reagent that limits the amount of product produced. The reactant in excess will either be stated in the problem or if you calculate...
Mon Oct 05, 2020 11:09 am
Forum: Balancing Chemical Reactions
Topic: Law of Conservation?
Replies: 16
Views: 150

### Re: Law of Conservation?

The moles of each atom are equal on either side of the equation, that's what matters. The stoichiometric coefficients are used to balance the moles of each atoms but they themselves do not equal each other on both sides of the equation. There are 2 moles of Na on either side, 2 moles of H and 2 mole...
Mon Oct 05, 2020 10:48 am
Forum: Molarity, Solutions, Dilutions
Topic: Dilutions
Replies: 10
Views: 111

### Re: Dilutions

The molarity does decrease during a dilution, but only due to the volume increasing. Since the volume is in the denominator, an increase in its value leads to an overall decrease in molarity. In simpler terms, you have the same amount of "stuff" (moles) but you just have more solution over...
Mon Oct 05, 2020 10:08 am
Forum: Limiting Reactant Calculations
Topic: Sapling Homework Question 10
Replies: 5
Views: 102

### Re: Sapling Homework Question 10

The reason that you know that 2-butanone is the limiting reactant is because it specifically states that the other reactant (propyl magnesiumbromide) is in excess. If this was not given, you could have to convert to moles and use mole to mole ratios and the whole process to determine the limiting re...