Search found 73 matches

by Samiha Molla 3G
Mon Jan 25, 2021 9:54 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Acid and Bases
Replies: 7
Views: 15

Re: Acid and Bases

There is a greater concentration of hydronium ions in acidic solutions. And for basic solutions, there is a greater concentration of hydroxide ions
by Samiha Molla 3G
Wed Jan 20, 2021 6:08 pm
Forum: Phase Changes & Related Calculations
Topic: Vapor vs gas
Replies: 31
Views: 75

Re: Vapor vs gas

I think they are used interchangeably like the others said! You also might see something referred to as a vapor when it's in the gaseous state (like "water vapor" when H20 is in a gas state).
by Samiha Molla 3G
Wed Jan 20, 2021 6:06 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Textbook 6D.13
Replies: 2
Views: 17

Re: Textbook 6D.13

The Cl isn't really too important because it's just a spectator ion. It's just more important to note that CH3NH3Cl is the conjugate acid since it has that extra H compared to CH3NH2.
by Samiha Molla 3G
Wed Jan 20, 2021 6:03 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: sapling #3
Replies: 5
Views: 39

Re: sapling #3

For this problem, lactic acid is acting as a weak acid, so the reaction would look like CH3CH(OH)COOH(aq) + H20 (l) -> H30+ + CH3CH(OH)COO-(aq). You can use an ICE box to find the H30+ concentration (x) which you can use to find the pH. Then you can get the pOH from there too, and you can use the va...
by Samiha Molla 3G
Tue Jan 19, 2021 4:47 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ICE table values
Replies: 20
Views: 58

Re: ICE table values

I think you could technically also use moles, but you would just have to be sure to convert that to mol/L when plugging values into the K equation. It might just be safer to use mol/L throughout!
by Samiha Molla 3G
Tue Jan 19, 2021 4:43 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: conjugate base
Replies: 14
Views: 51

Re: conjugate base

It would be a strong base! Like someone else said, they kind of have an opposing/inverse relationship.
by Samiha Molla 3G
Wed Jan 13, 2021 9:30 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: pKw formula
Replies: 4
Views: 18

Re: pKw formula

As the others mentioned, I think it can be used for any acid-base reactions, but you can use the result of it to estimate how strong/weak an acid or base is based on the pH/pOH values you have.
by Samiha Molla 3G
Wed Jan 13, 2021 9:28 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Salts
Replies: 5
Views: 21

Re: Salts

Salts don't have to have Na (but they could). It's just a term used to describe the product of an acid-base reaction!
by Samiha Molla 3G
Wed Jan 13, 2021 9:55 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Several Questions
Replies: 3
Views: 27

Re: Several Questions

1. Yes, you're right! I think H+ is just an easier way of writing H30+.
2. That's correct as well, we exclude solids and liquids but include gases and aqueous compounds.
by Samiha Molla 3G
Tue Jan 12, 2021 5:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kc and Kp
Replies: 5
Views: 22

Re: Kc and Kp

I think you just use whichever you're given/whichever value the problem says to find. Also just a note- I think if you have a reaction with both aqueous and gaseous products/reactants, you want them all to be consistent, so you would use Kc there instead of Kp and you'd have to convert the pressure ...
by Samiha Molla 3G
Tue Jan 12, 2021 5:19 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Bars
Replies: 8
Views: 33

Re: Bars

Yes, we are considering 1 bar = 1 atm!
by Samiha Molla 3G
Thu Jan 07, 2021 3:17 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: concentration or partial pressure
Replies: 7
Views: 39

Re: concentration or partial pressure

Since it's asking for molar concentration, and everything is given in the correct units of mol/L, I don't think you'd have to do any converting. If it asked for Kp though, then you would need the partial pressures!
by Samiha Molla 3G
Thu Jan 07, 2021 3:14 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Including H2O
Replies: 7
Views: 29

Re: Including H2O

I don't think we need to ever include liquids because the change in concentration is usually too small to have an effect on the K value.
by Samiha Molla 3G
Wed Jan 06, 2021 3:06 pm
Forum: General Science Questions
Topic: mole vs. M
Replies: 16
Views: 108

Re: mole vs. M

M represents molarity, so the units are mol/L like you said. Moles are often written as mol, so the molarity is the amount of moles per liter of solution.
by Samiha Molla 3G
Wed Jan 06, 2021 3:04 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Reverse Reactions
Replies: 12
Views: 46

Re: Reverse Reactions

We have to do this because the reactants and products are essentially switching places. So, what goes on top and what goes on the bottom of the equilibrium constant equation also switch places, which is the same as taking the reciprocal!
by Samiha Molla 3G
Wed Jan 06, 2021 3:02 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: True or False?
Replies: 4
Views: 30

Re: True or False?

As the others mentioned, this would be true. the equilbrium constant value is the ratio of products/reactants, so if you have more reactants, you will yield more products, and the Kc value will be higher.
by Samiha Molla 3G
Thu Dec 10, 2020 10:12 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Sapling Question 13
Replies: 4
Views: 48

Re: Sapling Question 13

So in this problem you're supposed to compare the pH value to the pKa value. Since the pH is greater than the pKa, the solution would be charged (more specifically it's a more basic solution- if it had been pKa > pH, then it would be more acidic). Hope this helps!
by Samiha Molla 3G
Wed Dec 09, 2020 10:00 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: HClO3
Replies: 2
Views: 7

Re: HClO3

I agree that it would be a strong acid. In homework problems and problems I've done in UA sessions, it's always been considered a strong acid, so I think it'll be the same for the exam!
by Samiha Molla 3G
Tue Dec 08, 2020 7:51 pm
Forum: Lewis Acids & Bases
Topic: Strong Acid Mnemonic
Replies: 2
Views: 34

Re: Strong Acid Mnemonic

Yeah it's:
SO I BRought NO CLean CLOthes
by Samiha Molla 3G
Tue Dec 08, 2020 7:50 pm
Forum: Properties & Structures of Inorganic & Organic Bases
Topic: Hydroxides vs Oxides
Replies: 2
Views: 32

Re: Hydroxides vs Oxides

I think hydroxides just end in OH (ie. LiOH) and oxides end in O (ie. Li2O). And for the importance, both group 1 and group 2 hydroxides and oxides are usually strong bases, so if you see a group 1/2 element ending in OH or O, it's likely it's a strong base if that's something you're trying to deter...
by Samiha Molla 3G
Mon Dec 07, 2020 8:12 pm
Forum: Bronsted Acids & Bases
Topic: electronegativity and acidity
Replies: 3
Views: 30

electronegativity and acidity

If you're comparing two acids, like HCl and HI, why is it that HCl is considered more acidic based on electronegativity? Cl is more electronegative than I, so wouldn't it be a weaker acid since the atoms would dissociate less readily? This is based off the Week 10 Sapling hw #11 by the way, thank you!
by Samiha Molla 3G
Mon Dec 07, 2020 11:47 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate vs Monodentate
Replies: 4
Views: 48

Re: Polydentate vs Monodentate

For me the best way to tell is by drawing out the Lewis Structure. If there are multiple available lone pairs that could act as bonding sites, then it would be polydentate; if there's only one set of available lone pair electrons then it would be monodentate. Hope that helps!
by Samiha Molla 3G
Wed Dec 02, 2020 6:38 pm
Forum: Biological Examples
Topic: chelates
Replies: 8
Views: 70

Re: chelates

A chelate is just a coordination compound that has ligands forming a ring around the TM cation. If you just google chelates and look on images it'll probably help to visualize what this looks like. Hope that helps!
by Samiha Molla 3G
Tue Dec 01, 2020 5:29 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Focus Exercise 2.27
Replies: 4
Views: 35

Re: Focus Exercise 2.27

I think it just means that there are no unpaired electrons, and like you mentioned none of them have those!
by Samiha Molla 3G
Tue Dec 01, 2020 12:45 pm
Forum: Naming
Topic: Textbook 9C.1
Replies: 6
Views: 73

Re: Textbook 9C.1

Like the others said, I think the terms are interchangeable! Dr. Lavelle mentioned that in the lecture from Monday.
by Samiha Molla 3G
Tue Dec 01, 2020 12:39 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: H20 to H2S
Replies: 4
Views: 69

Re: H20 to H2S

I think that there can only be hydrogen bonds when there is an H attached to an N,O, or F that attaches to another N, O, or F that has an available lone pair. I don't think that H2O to H2S would have a hydrogen bond since the lone pair is on an S atom, not an N, O, or F atom.
by Samiha Molla 3G
Mon Nov 30, 2020 3:09 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Delocalized vs localized
Replies: 12
Views: 82

Re: Delocalized vs localized

I think of resonance structures when I see "delocalized". delocalized electrons are not fixed in a certain position on a single atom and they can move around. localized electrons are the opposite- they remain near only one atom.
by Samiha Molla 3G
Tue Nov 24, 2020 1:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Textbook question 2E.1
Replies: 2
Views: 14

Re: Textbook question 2E.1

I thought the same thing at first! But I found out that you can also have linear shape in the case of an atom having three lone pairs and two outer atoms.
by Samiha Molla 3G
Tue Nov 24, 2020 1:43 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sampling Week 7/8 #6
Replies: 6
Views: 46

Re: Sampling Week 7/8 #6

Like the others said, the structure would be linear if there were just 2 outer atoms and no lone pairs. SF2 has has two outer atoms and two lone pairs though, so I think it would be bent instead!
by Samiha Molla 3G
Tue Nov 24, 2020 1:41 pm
Forum: Sigma & Pi Bonds
Topic: Sigma and pi bonds relation to covalent bonds
Replies: 6
Views: 48

Re: Sigma and pi bonds relation to covalent bonds

If there is just a single bond, there is just one sigma bond. If there is a double bond, there is one sigma bond and one pi bond. And if there is a triple bond, there is one sigma bond and 2 pi bonds. hope this helps!
by Samiha Molla 3G
Tue Nov 24, 2020 1:38 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: What is bond order?
Replies: 8
Views: 108

Re: What is bond order?

Bond order is just the number of bonds present between atoms. So if you had a single bond between two atoms, the bond order would be 1. If you had a double bond between two atoms, the bond order would be 2, so on and so forth
by Samiha Molla 3G
Tue Nov 24, 2020 1:35 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Overlapping Orbitals
Replies: 3
Views: 29

Re: Overlapping Orbitals

This was mentioned in one of the recent lectures! Sigma bonds are end to end, pi bonds are side to side.
by Samiha Molla 3G
Wed Nov 18, 2020 3:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Arrangement of Electrons = Electron Pair Geometry
Replies: 2
Views: 31

Re: Arrangement of Electrons = Electron Pair Geometry

Yes, I think he is referring to them as the same thing since electron pair geometry influences the shape!
by Samiha Molla 3G
Wed Nov 18, 2020 3:28 pm
Forum: Bond Lengths & Energies
Topic: Dissociation Energy and Unpaired Electrons
Replies: 3
Views: 37

Re: Dissociation Energy and Unpaired Electrons

I was thinking that in this context "unpaired" is lone pairs that aren't bonded to another atom. And like you said, that would cause weaker bonds and lower dissociation energy because of electron electron repulsion. I do see your point though because I think the same term is used for radic...
by Samiha Molla 3G
Tue Nov 17, 2020 10:49 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 1E.5 b
Replies: 2
Views: 19

Re: 1E.5 b

Yes I think you're correct! I read in the textbook that penetrate in this context means that s-electrons can be found in the inner shells of an atom and therefore close to the nucleus.
by Samiha Molla 3G
Tue Nov 17, 2020 10:45 am
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability and Polarizing Power
Replies: 5
Views: 32

Re: Polarizability and Polarizing Power

Polarizability is how much an anion's electron cloud can be distorted. Bigger atoms are more polarizable because they are less electronegative, so their electrons are less tightly held and more likely to be distorted by another atom's electron cloud. Polarizing power is how much a cation can distort...
by Samiha Molla 3G
Mon Nov 16, 2020 4:20 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Factors Affecting Electron Energy in Multi-Electron Atom
Replies: 5
Views: 48

Re: Factors Affecting Electron Energy in Multi-Electron Atom

I had the same question about this objective, and I think the others are right that it's mainly referring to shielding!
by Samiha Molla 3G
Thu Nov 12, 2020 11:48 am
Forum: Formal Charge and Oxidation Numbers
Topic: charge of atom
Replies: 2
Views: 43

Re: charge of atom

I'm not sure about whether or not there is a relationship between magnetic spin and charge. You can look at the periodic table though to get some insight about atoms' charges. If you just look up periodic table & charge online you can see how elements in certain groups have specific charges. hop...
by Samiha Molla 3G
Wed Nov 11, 2020 7:25 pm
Forum: Lewis Structures
Topic: homework 2B.3
Replies: 5
Views: 44

Re: homework 2B.3

Like the others said, Br is one of the exceptions to the octet rule where it can have more than 8 electrons in its valence shell. This also applies for other elements that have d orbitals because the d orbitals can allow for the atom to accommodate for more than an octet!
by Samiha Molla 3G
Wed Nov 11, 2020 6:00 pm
Forum: Bond Lengths & Energies
Topic: Bond Strength Clarification
Replies: 5
Views: 62

Re: Bond Strength Clarification

thank you!
by Samiha Molla 3G
Wed Nov 11, 2020 12:23 pm
Forum: Bond Lengths & Energies
Topic: Bond Strength Clarification
Replies: 5
Views: 62

Bond Strength Clarification

Hi I just wanted to clarify how the strengths of bonds relate to atomic/molecular size. For two atoms interacting, is the bond stronger and shorter between two small atoms and weaker and longer between two larger atoms? And would the opposite be true for molecules - two large molecules would have st...
by Samiha Molla 3G
Tue Nov 10, 2020 1:47 pm
Forum: Electronegativity
Topic: Electronegativity Difference Between 1.5 and 2
Replies: 2
Views: 27

Re: Electronegativity Difference Between 1.5 and 2

Hi, I think I remember hearing in office hours that we would need more information about the molecules themselves for differences between those values.
by Samiha Molla 3G
Mon Nov 09, 2020 7:25 pm
Forum: Lewis Structures
Topic: Sapling 2b.1
Replies: 2
Views: 27

Sapling 2b.1

Hi, for 2b.1 part c in the textbook (asks for the Lewis structure of ONF), why is N the central atom rather than O? I thought I heard in a workshop that O is an exception to the ionization energy trend because the 2 paired electrons in its 2p subshell create electron-electron repulsion, which makes ...
by Samiha Molla 3G
Wed Nov 04, 2020 8:35 pm
Forum: Trends in The Periodic Table
Topic: Van der Waals radius
Replies: 3
Views: 40

Re: Van der Waals radius

Thank you guys!! I asked Dr. Lavelle about it today during his office hours, and he mentioned that the Van Der Waals radius applies to an atom by itself in the gas phase. So I guess it's different than covalent and ionic in that way, as there aren't two atoms being used to measure. He also mentioned...
by Samiha Molla 3G
Wed Nov 04, 2020 3:48 pm
Forum: Trends in The Periodic Table
Topic: Van der Waals radius
Replies: 3
Views: 40

Van der Waals radius

Hi, I noticed the textbook mentioned something about Van der Waals radii in addition to covalent and ionic radii and I was wondering if anyone could explain them a bit better. I don't remember hearing about them in lecture but I may have missed it. Thank you!
by Samiha Molla 3G
Tue Nov 03, 2020 8:45 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Element orbital representation
Replies: 4
Views: 74

Re: Element orbital representation

I think any time you do a noble gas configuration, you have to write out everything after the previous noble gas, including the electrons in subshells that don't have valence electrons.
by Samiha Molla 3G
Mon Nov 02, 2020 5:49 pm
Forum: Administrative Questions and Class Announcements
Topic: Unable to access week 5-6 homework
Replies: 6
Views: 63

Re: Unable to access week 5-6 homework

Dr. Lavelle mentioned in office hours today that the homework will be available later today!
by Samiha Molla 3G
Mon Nov 02, 2020 5:47 pm
Forum: General Science Questions
Topic: Midterm Grades
Replies: 30
Views: 344

Re: Midterm Grades

In office hours today he mentioned grades will be updated by Thursday!
by Samiha Molla 3G
Thu Oct 29, 2020 10:37 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra
Replies: 4
Views: 45

Re: Atomic Spectra

An electron loses energy when dropping from a high energy level to a low one, and that energy has to go somewhere. This is just saying that the energy is released as a photon of light, which is why we see atomic spectra lines/colors, because the light is a certain wavelength that gives off a color. ...
by Samiha Molla 3G
Thu Oct 29, 2020 10:32 am
Forum: Einstein Equation
Topic: E=pv and E=pc
Replies: 6
Views: 115

Re: E=pv and E=pc

I don't know a whole lot about these either, but I believe it's just a way to relate momentum and velocity for waves, since we would only use the deBroglie equation (that also relates to momentum) for particles. E=pc is the same as E=pv, but it is just specific to light as the velocity, v, is replac...
by Samiha Molla 3G
Tue Oct 27, 2020 12:27 pm
Forum: Properties of Light
Topic: 18 on Wave Properties of Electrons and De Broglie Equation Module
Replies: 1
Views: 25

Re: 18 on Wave Properties of Electrons and De Broglie Equation Module

I think this is just referring to the wave-particle duality of light and the double slit experiment. The double slit experiment found that light acts like a wave since it produces a diffraction pattern when it is shone through two slits in a barrier, rather than just shining through directly in a st...
by Samiha Molla 3G
Tue Oct 27, 2020 12:16 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra AV Module
Replies: 2
Views: 22

Re: Atomic Spectra AV Module

Because frequency can't be negative, you will either want R and what's in the parentheses to both be negative(so the negatives cancel) or both be positive. For me, I have been using v=R(1/nf^2 - 1/ni^2) which seems to work best. I always use nfinal as the lower energy level, even if the question sa...
by Samiha Molla 3G
Tue Oct 27, 2020 11:49 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra AV Module
Replies: 2
Views: 22

Atomic Spectra AV Module

Hi, I was a bit confused about this note made regarding the Rydberg equation in the Atomic Spectra AV module video. If R is already negative, why would we need to have a negative sign between the terms as well? I might just have the equation written down incorrectly..thank you in advance!
by Samiha Molla 3G
Tue Oct 27, 2020 11:10 am
Forum: Student Social/Study Group
Topic: external camera
Replies: 5
Views: 52

Re: external camera

Yep you just need one external camera and something with Respondus downloaded to take the exam on
by Samiha Molla 3G
Mon Oct 26, 2020 3:29 pm
Forum: Student Social/Study Group
Topic: Additional Help/ Workshops
Replies: 7
Views: 78

Re: Additional Help/ Workshops

They are really helpful! At one I went to this week, the UA prepared content review/notes for some of the midterm concepts and practice problems she made herself that were different from the homework/textbook problems If it's too much to ask what are some topics that they brought up that were of gr...
by Samiha Molla 3G
Mon Oct 26, 2020 3:25 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Schrodinger's Equation
Replies: 3
Views: 41

Re: Schrodinger's Equation

Dr. Lavelle mentioned in office hours to not worry too much about this for the midterm, as we are not expected to know any of the math behind it!
by Samiha Molla 3G
Wed Oct 21, 2020 3:50 pm
Forum: Student Social/Study Group
Topic: Additional Help/ Workshops
Replies: 7
Views: 78

Re: Additional Help/ Workshops

They are really helpful! At one I went to this week, the UA prepared content review/notes for some of the midterm concepts and practice problems she made herself that were different from the homework/textbook problems
by Samiha Molla 3G
Wed Oct 21, 2020 3:47 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbitals and Schrodinger's Wave Function
Replies: 2
Views: 23

Re: Orbitals and Schrodinger's Wave Function

Think about density as how you would think about it in every day life- if something is densely packed with some material, you'll find a lot of that material there. So if there is high electron density in an orbital, there is a high chance you'll find an electron there. Hope that helps!
by Samiha Molla 3G
Wed Oct 21, 2020 2:32 pm
Forum: General Science Questions
Topic: Lecture Question
Replies: 4
Views: 49

Re: Lecture Question

I think this is a known value that we would be given on an exam!
by Samiha Molla 3G
Tue Oct 20, 2020 12:53 pm
Forum: Administrative Questions and Class Announcements
Topic: The Midterm
Replies: 9
Views: 77

Re: The Midterm

yes, we will have an equation/constants sheet. it's going to be the same one on Dr. Lavelle's site, but he mentioned to wait until he emails info about the midterm as he will likely be updating the sheet up until then!
by Samiha Molla 3G
Tue Oct 20, 2020 12:47 pm
Forum: Properties of Electrons
Topic: Sapling Q 4 Part 2
Replies: 3
Views: 22

Re: Sapling Q 4 Part 2

so you would basically just do (energy per photon)(x) = (total energy) where x = the number of photons needed to eject however many electrons, and (energy per photon) = the number you calculated in part one. since each photon ejects one electron, the number of photons and electrons are the same. hop...
by Samiha Molla 3G
Thu Oct 15, 2020 5:50 pm
Forum: Properties of Light
Topic: Textbook Problem 1A.3
Replies: 3
Views: 43

Re: Textbook Problem 1A.3

we did this problem in a UA session today and the UA said not to worry about this part too much since we haven't really talked about it in lecture. but the way he explained it was that the extent of change in the electrical field is proportional to the amplitude of the wave. since the frequency is d...
by Samiha Molla 3G
Wed Oct 14, 2020 6:15 pm
Forum: Properties of Light
Topic: Relationship between energy of photon and energy to remove
Replies: 5
Views: 44

Re: Relationship between energy of photon and energy to remove

yes you're right, the energy of the photon has to be greater than or equal to the threshold energy for the electron to be removed.
by Samiha Molla 3G
Wed Oct 14, 2020 6:05 pm
Forum: Administrative Questions and Class Announcements
Topic: Textbook Practice Problems Solutions
Replies: 2
Views: 31

Re: Textbook Practice Problems Solutions

They're listed on the home page of Sapling once you log in, under a PDF called "Atkins 7e SSM"
by Samiha Molla 3G
Tue Oct 13, 2020 9:06 pm
Forum: Limiting Reactant Calculations
Topic: M11 Textbook Problem
Replies: 2
Views: 55

Re: M11 Textbook Problem

I think in this case since it asks for the final product's limiting reactant, you have to look at both steps to find out what that is. also, since this problem says that there must be enough oxygen present for the second step to take place, i think you can kind of predict that oxygen will be the lim...
by Samiha Molla 3G
Mon Oct 12, 2020 4:24 pm
Forum: Molarity, Solutions, Dilutions
Topic: G.25 conceptual question
Replies: 1
Views: 37

G.25 conceptual question

Hi, someone asked about this textbook question a couple days ago but I'm still confused on the explanations. I thought the number of moles of a solute don't change throughout dilutions. this question asks about the number of molecules, but I thought that number would also be the same after dilutions...
by Samiha Molla 3G
Mon Oct 12, 2020 2:16 pm
Forum: Empirical & Molecular Formulas
Topic: Stoichiometric Coefficients
Replies: 3
Views: 63

Re: Stoichiometric Coefficients

those were both really helpful thank you!
by Samiha Molla 3G
Sun Oct 11, 2020 10:33 am
Forum: Empirical & Molecular Formulas
Topic: Stoichiometric Coefficients
Replies: 3
Views: 63

Stoichiometric Coefficients

Hi, I was wondering if anyone could explain what exactly stoichiometric coefficients represent, specifically if they represent the number of moles or the number of atoms of an element in a compound? i thought the definitions for empirical and molecular formulas indicate that they rep the number of a...
by Samiha Molla 3G
Thu Oct 08, 2020 8:52 pm
Forum: Molarity, Solutions, Dilutions
Topic: Density in Stoichiometry
Replies: 5
Views: 51

Re: Density in Stoichiometry

I think you could use density to find the mass of the reactants since you are given both the volumes and densities of the reactants. you could set up a stoichiometry problem so that the units of density (g/ml) and the volume (ml or L) cancel out so you are just left with the mass (g).
by Samiha Molla 3G
Thu Oct 08, 2020 8:46 pm
Forum: Balancing Chemical Reactions
Topic: Fractions
Replies: 14
Views: 108

Re: Fractions

I think Dr. Lavelle mentioned that it's more technically correct to use whole numbers for stoichiometric coefficients!
by Samiha Molla 3G
Wed Oct 07, 2020 4:06 pm
Forum: Significant Figures
Topic: Clarification on Significant Figures
Replies: 9
Views: 67

Re: Clarification on Significant Figures

I could possibly be wrong here, but I think that leading zeros are the zeros that do not count. For instance, 0.034 would have only 2 sig figs, whereas 0.304 would have 3 sig figs since the zero second zero is in the middle and not leading. However, I am a bit rusty on sig fig rules, so feel free t...
by Samiha Molla 3G
Tue Oct 06, 2020 3:43 pm
Forum: Empirical & Molecular Formulas
Topic: Sapling HW 9
Replies: 21
Views: 225

Re: Sapling HW 9

I was having the same question and yes, they do need to be converted to moles first. then you can divide by the smallest number of moles to get the ratios for the empirical formula!
by Samiha Molla 3G
Mon Oct 05, 2020 6:24 pm
Forum: Balancing Chemical Reactions
Topic: Law of Conservation?
Replies: 16
Views: 150

Re: Law of Conservation?

the stoichiometric coefficients represent the number of moles (number of atoms) as you noted, but not to the masses. the masses on both sides of the equation should still be equivalent according to the law of conservation!

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