Search found 61 matches

by Layal Suboh 1I
Wed Mar 13, 2019 5:24 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Pre-equilibrium approach
Replies: 4
Views: 44

Pre-equilibrium approach

When do we use the pre-equilibrium approach?
by Layal Suboh 1I
Wed Mar 13, 2019 5:18 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: catalyst vs intermediate
Replies: 3
Views: 29

Re: catalyst vs intermediate

Intermediates are produced and then consumed, so they will be on the products side for one step and then on the reactants side for a second step. Catalysts are present in the beginning of the reaction (on the reactants for the first step) and present in the end of the reaction (on the products for t...
by Layal Suboh 1I
Wed Mar 13, 2019 5:12 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Kinetically v. Thermodynamically Controlled Reaction
Replies: 2
Views: 27

Kinetically v. Thermodynamically Controlled Reaction

What does it mean for a reaction to be kinetically/thermodynamically controlled? How does temperature affect a reaction that is kinetically controlled?
by Layal Suboh 1I
Wed Mar 06, 2019 2:07 pm
Forum: First Order Reactions
Topic: Pseudo-First-Order Reaction
Replies: 5
Views: 60

Re: Pseudo-First-Order Reaction

I think when are there are multiple reactants, we treat the reaction as a pseudo-reaction. It's difficult to study a reaction when the concentrations of multiple reactants are changing, so we let one reactant change and keep the others constant.
by Layal Suboh 1I
Wed Mar 06, 2019 2:03 pm
Forum: General Rate Laws
Topic: Difference between instantaneous and unique rate
Replies: 3
Views: 20

Difference between instantaneous and unique rate

Other than the unique rates have coefficients in the equation, what is the difference between instantaneous and unique rate? What does it mean that the unique rate is the same for all reactants and products in that unique reaction?
by Layal Suboh 1I
Wed Mar 06, 2019 2:00 pm
Forum: Zero Order Reactions
Topic: General Meaning of "Zero Order" Reactions
Replies: 7
Views: 61

General Meaning of "Zero Order" Reactions

What does it mean for a reaction to have zero order?
by Layal Suboh 1I
Tue Feb 26, 2019 8:43 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Stoichiometric Coefficients in Cell Diagrams
Replies: 2
Views: 21

Stoichiometric Coefficients in Cell Diagrams

Are stoichiometric coefficients included in cell diagrams?
by Layal Suboh 1I
Tue Feb 26, 2019 8:43 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: H2O and H+ in Cell Diagrams
Replies: 1
Views: 27

H2O and H+ in Cell Diagrams

Are H2O and H+ included in a cell diagram? In 6M.5 part c, the solutions manual contains H+ in the cell diagram.
by Layal Suboh 1I
Tue Feb 26, 2019 2:54 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: 6M.1 7th Ed
Replies: 1
Views: 21

6M.1 7th Ed

Hello, I'm having trouble with this problem. It says: A student was given a standard Cu(s)|Cu2+(aq) half-cell and another half-cell containing an unknown metal M in 1.00 M M(NO3)2 (aq) and formed the cell M(s)|M+(aq)||Cu2+(aq)|Cu(s). The cell potential was found to be -0.689 V. What is the value of ...
by Layal Suboh 1I
Wed Feb 20, 2019 4:45 pm
Forum: Balancing Redox Reactions
Topic: Adding Salt Bridge/Porous Disk to Reaction Beakers
Replies: 2
Views: 38

Adding Salt Bridge/Porous Disk to Reaction Beakers

Dr. Lavelle discussed that a salt bridge or porous disk must be added to reaction beakers to remain neutral. What is the purpose of that?
by Layal Suboh 1I
Wed Feb 20, 2019 4:41 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Potential Difference Between Electrodes
Replies: 1
Views: 27

Potential Difference Between Electrodes

Why is the maximum potential difference calculated when there is very little current flow?
by Layal Suboh 1I
Wed Feb 20, 2019 4:38 pm
Forum: Balancing Redox Reactions
Topic: Determining Oxidation State
Replies: 2
Views: 23

Determining Oxidation State

Hello, Today in lecture Dr. Lavelle discussed the chem reaction 8H+ + MnO4- + 5Fe2+ --> Mn2+ +5Fe3+ + 4H2O How did we determine that iron was oxidized and lost 5 electrons? I know that manganese was reduced because its oxidation number went from +7 to +2, and iron was oxidized because it went from 2...
by Layal Suboh 1I
Tue Feb 12, 2019 10:15 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Extensive v. Intensive Property of Heat Capacities
Replies: 3
Views: 61

Extensive v. Intensive Property of Heat Capacities

Why are heat capacities extensive, but specific and molar heat capacities intensive properties?
by Layal Suboh 1I
Tue Feb 12, 2019 10:12 pm
Forum: Calculating Work of Expansion
Topic: Substituting -nrT for -PΔV
Replies: 4
Views: 74

Substituting -nrT for -PΔV

Hello,

When substituting -nrT for -PΔV, how do you know what changing (moles or temperature)?
by Layal Suboh 1I
Tue Feb 12, 2019 10:08 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: Entropy at 0 K
Replies: 6
Views: 72

Entropy at 0 K

Hello,

Is it possible to have 0 entropy? Also, what is the difference between residual, translational, vibrational, and transitional entropy?

Thanks
by Layal Suboh 1I
Wed Feb 06, 2019 5:15 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: U= 3/2nRT
Replies: 2
Views: 68

U= 3/2nRT

Hello,

When is the equation U= 3/2 nrT used? Is it only applicable when the system is isothermal? Also, for this question, is the volume constant and pressure changing?

Thanks!
by Layal Suboh 1I
Wed Feb 06, 2019 5:00 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Determining Spontaneity of a Reaction
Replies: 4
Views: 56

Determining Spontaneity of a Reaction

Hello,

Why do we need to know both enthalpy and entropy to determine if the reaction will occur spontaneously? If the reaction is exothermic, won't the products be favored?

Thanks
by Layal Suboh 1I
Wed Feb 06, 2019 4:56 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Constant Pressure/Volume
Replies: 6
Views: 79

Constant Pressure/Volume

Hello, Dr. Lavelle went over a question in class last week that said "an exothermic reaction occurs an open beaker producing a net 8 moles of gas at 25 C. What is the change in internal energy?" How do we know that this reaction is occurring under conditions of constant pressure? Thanks!
by Layal Suboh 1I
Wed Jan 30, 2019 10:46 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Calculating Reaction Enthalpies
Replies: 1
Views: 24

Calculating Reaction Enthalpies

Hello,

When will we know when do use the different methods for calculating reaction enthalpies?
by Layal Suboh 1I
Wed Jan 30, 2019 10:45 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat Capacity
Replies: 5
Views: 48

Heat Capacity

Hello,

I'm confused about the difference between an extensive property and an intensive property.What is the significance of each?
by Layal Suboh 1I
Wed Jan 30, 2019 10:43 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy of Reaction v. Enthalpy of Formation
Replies: 1
Views: 32

Enthalpy of Reaction v. Enthalpy of Formation

Hello,

What is the difference between the enthalpy of reaction and the enthalpy of formation? Are they calculated the same way?


Thanks
by Layal Suboh 1I
Thu Jan 24, 2019 8:32 pm
Forum: Phase Changes & Related Calculations
Topic: Why steam at 100 C burns more than liquid at 100 C
Replies: 2
Views: 30

Why steam at 100 C burns more than liquid at 100 C

Hello,

I'm still confused about why steam causes more severe burns at 100 degrees celsius compared to liquid at 100 degrees celsius. Is it because more energy is required for liquid to become gas, so it releases more energy when it touches skin (which is significantly cooler than steam)?

Thanks!
by Layal Suboh 1I
Thu Jan 24, 2019 8:17 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Weak Acids and Bases
Replies: 2
Views: 42

Re: Weak Acids and Bases

Usually, if you are given a Kb value, then you know it's a weak base. Also, there are 6 strong bases: LiOH, NaOH, KOH, Ca(OH)2, Sr(OH)2, Ba(OH)2.
by Layal Suboh 1I
Thu Jan 24, 2019 3:03 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5% Rule and % Deprotonation
Replies: 3
Views: 53

5% Rule and % Deprotonation

Hello,

Is the 5% rule calculated the same way as percent deprotonation/protonation?
by Layal Suboh 1I
Wed Jan 16, 2019 5:14 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: pH of Hydronium Ion
Replies: 1
Views: 24

pH of Hydronium Ion

In class today, Dr. Lavelle said that if the concentration of hydronium ion is less than 10^-7, then the solution is considered neutral. I understand that it is because the pH would be greater than 7, which is considered basic, but why exactly would the concentration of hydronium ion in a solution r...
by Layal Suboh 1I
Wed Jan 16, 2019 5:08 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Solids and liquids in K
Replies: 6
Views: 73

Re: Solids and liquids in K

Solids and liquids are not included because they do not affect the reaction amount at equilibrium. Solids remain as solids, so their concentration will not change. Also, we assume that there is a large excess of solvent in the reaction, so liquids will remain at the end of the reaction (cancel out i...
by Layal Suboh 1I
Tue Jan 15, 2019 8:02 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: HW 6B.11 7th Ed
Replies: 1
Views: 34

HW 6B.11 7th Ed

Hello, I'm having difficulty with this problem It says: A student added solid Na2O to a volumetric flaks of volume 200.0 mL, which was then filled with water, resulting in 200.0 mL of NaOH solution. Then 5.00 mL of the solution was transferred to another volumetric flask and diluted to 500.0 mL. The...
by Layal Suboh 1I
Sat Jan 12, 2019 11:03 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Le Chatelier's Principle: Change in temperature
Replies: 2
Views: 44

Le Chatelier's Principle: Change in temperature

Hello, I'm a bit confused about how changing temperature changes K. I understand that if the reaction requires heat to form products, then heating will favor products and if the reaction releases heat to form products, then heating will favor reactions, but how does this affect K? Wouldn't the react...
by Layal Suboh 1I
Thu Jan 10, 2019 2:27 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Explaining Q<K and Q>K [ENDORSED]
Replies: 7
Views: 116

Re: Explaining Q<K and Q>K [ENDORSED]

If Q<K, more reactants are present in the reaction (Dr. Lavelle said that there may be some other source adding reactant) than products being removed, so in order to decrease the amount of reactant to reach equilibrium, the forward reaction is favored to produce more product. If Q>K, there is a high...
by Layal Suboh 1I
Wed Jan 09, 2019 7:41 pm
Forum: Ideal Gases
Topic: Value of K
Replies: 6
Views: 74

Re: Value of K

When K > 1, the equilibrium favors the formation of products. When k < 1, the equilibrium favors the decomposition back to reactants. When k=1, there is the same concentration of reactants and products.

Hope this helps!
by Layal Suboh 1I
Fri Dec 07, 2018 10:12 pm
Forum: Hybridization
Topic: The purpose of hybridization
Replies: 1
Views: 50

Re: The purpose of hybridization

Hybridization gives the correct number of bonds. For example, using atomic orbitals, CH4 could only form two bonds, but we know that carbon forms 4 bonds. When you use hybrid orbitals, there are four hybrid orbitals (sp^3), which allows carbon to form 4 bonds. Also, the bond angles are incorrect for...
by Layal Suboh 1I
Fri Dec 07, 2018 10:07 pm
Forum: Amphoteric Compounds
Topic: Recognizing Amphoteric Compounds
Replies: 1
Views: 29

Recognizing Amphoteric Compounds

What makes certain elements have acid or basic quality in certain compounds? Also, is there a way to know whether something is amphoteric or not, or do we just have to memorize them?
by Layal Suboh 1I
Fri Dec 07, 2018 10:04 pm
Forum: Calculating the pH of Salt Solutions
Topic: 7th edition 6B number 3
Replies: 1
Views: 33

Re: 7th edition 6B number 3

HCL is already in units of concentration (mol/L), so in order to find the number of moles, you would have to multiply by 200 mL (.2 L). In order to find the pH of the desired solution, you take the -log[.025 M]. In order to find the actual pH, you would need to divide the number of moles by .25 L an...
by Layal Suboh 1I
Wed Dec 05, 2018 6:20 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Strength of Acids
Replies: 1
Views: 38

Strength of Acids

Why is acetic acid stronger than formic acid? The only difference between the two structures is the extra two hydrogens on acetic acid, so I'm confused to as to why it's stronger. Does it have something to do with being an oxoacid?

Thanks!
by Layal Suboh 1I
Fri Nov 30, 2018 3:28 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Amines and strength of acid
Replies: 4
Views: 49

Re: Amines and strength of acid

Amines are bases. For example, in ammonia, NH3, the nitrogen has a lone pair, making it a base. Amines are considered weaker bases because they are not completely ionized in water.
by Layal Suboh 1I
Fri Nov 30, 2018 3:24 pm
Forum: Hybridization
Topic: 2s or s?
Replies: 7
Views: 71

Re: 2s or s?

2s specifics the energy level and the orbital of the atom. S just refers to what type of orbital.
by Layal Suboh 1I
Fri Nov 30, 2018 11:25 am
Forum: Electronegativity
Topic: 7th Edition 3F.15
Replies: 2
Views: 60

Re: 7th Edition 3F.15

AsF3 is polar because it has a lone pair, so the dipoles do not completely cancel. All the dipoles in AsF5 cancel, that's why it is non polar. Because AsF3 is polar, it has dipole-dipole intermolecular forces, so its boiling point would be higher.

Hope this helps!
by Layal Suboh 1I
Tue Nov 20, 2018 8:31 pm
Forum: Dipole Moments
Topic: Dipole Moment
Replies: 1
Views: 22

Dipole Moment

When are tetrahedrals polar and non polar? For example, a molecule like CCl4 is non polar because the atoms around Carbon are the same, but wouldn't there still be a dipole moment because of the 109.5 angle? I'm a little confused about when you know a molecule (in two planes) is polar or nonpolar.
by Layal Suboh 1I
Tue Nov 20, 2018 8:18 pm
Forum: Lewis Structures
Topic: Lewis structure for POCl3
Replies: 7
Views: 104

Re: Lewis structure for POCl3

I think P is in the middle because it is the least electronegative. When drawing lewis structures, the least electronegative atoms goes in the middle, which in this case, would be phosphorus because it is lower on the periodic table.
by Layal Suboh 1I
Tue Nov 20, 2018 4:25 pm
Forum: Hybridization
Topic: Homework Question 7th Edition 2F.15
Replies: 2
Views: 34

Homework Question 7th Edition 2F.15

Hello, I'm having a little difficulty understanding this question: Noting that the bond angle of an sp3 hybridized atom is 109.5 and that of an sp2 hybridized atom is 120, do you expect the bond angle between two hybrid orbitals to increase or decrease as the s-character of the hybrids is increased?...
by Layal Suboh 1I
Wed Nov 14, 2018 5:08 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: London Dispersion Forces
Replies: 2
Views: 74

London Dispersion Forces

In class, we talked about the different intermolecular forces, and Dr. Lavelle mentioned that London Dispersion Forces are the weakest. What exactly are London Dispersion Forces, and why are they much weaker?


Thanks
by Layal Suboh 1I
Wed Nov 14, 2018 5:03 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability v. Polarizing Power
Replies: 2
Views: 90

Polarizability v. Polarizing Power

Hello, I'm a little confused by the difference between polarizability and polarizing power. I know the polarizability refers to the large size of anions, and polarizing power refers to small size cations, but what exactly is the reason for how strongly a cation can polarize an anion and how easily a...
by Layal Suboh 1I
Wed Nov 14, 2018 4:52 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: Polar v. Non Polar
Replies: 7
Views: 131

Re: Polar v. Non Polar

Hi! You can determine if some molecules are polar based on the difference in electronegativity of the bond (ie if the difference in electronegativity is between 0 and 0.4, the bond is non polar. If the difference is between 0.5 and 1.4, the bond is polar) . For example, N2 is non-polar because the d...
by Layal Suboh 1I
Wed Nov 07, 2018 6:57 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: Liquid and Solid Formations for Non-polar Atoms and Molecules
Replies: 2
Views: 40

Liquid and Solid Formations for Non-polar Atoms and Molecules

In class today, Dr. Lavelle discussed how electron distortion and polarizability can predict states of matter for certain molecules (like methane and pentane). I'm having a little trouble understanding how the size or molar mass can predict if a molecule is a solid, liquid, or gas. If someone could ...
by Layal Suboh 1I
Wed Nov 07, 2018 6:52 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability
Replies: 2
Views: 63

Polarizability

Hello,

I'm having difficulty understanding polarity. I know that it causes a separation of charge (for example, O becoming slightly negative and H becoming slight positive), but what does it mean that polarity is how easily electrons are distorted?

Thanks
by Layal Suboh 1I
Tue Nov 06, 2018 7:29 pm
Forum: Resonance Structures
Topic: Resonance Hybrids
Replies: 3
Views: 70

Resonance Hybrids

Hello,

Does the octet rule have to be fulfilled for resonance hybrids? Is it possible to draw resonance for a molecule that's central atom does not have a complete octet?

Thanks
by Layal Suboh 1I
Wed Oct 31, 2018 9:20 pm
Forum: Lewis Structures
Topic: Double bonds [ENDORSED]
Replies: 3
Views: 83

Double bonds [ENDORSED]

Hello,

I'm having troubling knowing when to add double bonds to a lewis structure. When do you know when to change a lone pair to a double bond? Also, when do you know when to stop adding doubling bonds?

Thanks
by Layal Suboh 1I
Wed Oct 31, 2018 9:17 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Question 2A.9 7th Edition
Replies: 1
Views: 33

Question 2A.9 7th Edition

Hi, I'm having difficulty with this problem from the homework: Which M3+ ions (where M is a metal) are predicted have the following ground-state electron configurations: (a) [Ar] 3d6; (b) [Ar] 3d5; (c) [Kr] 4d5; (d) 4d3. I thought you would add 3 electrons to each electron configuration, but the ans...
by Layal Suboh 1I
Wed Oct 31, 2018 6:32 pm
Forum: Ionic & Covalent Bonds
Topic: Question 2A.23 7th Edition
Replies: 1
Views: 65

Question 2A.23 7th Edition

Hi, I'm having difficulty with solving this question from the homework: On the basis of the expected charges of the monatomic ions, give the chemical formula of each of the following compounds: a) manganese arsenide; b) indium (III) sulfide; c) aluminum hydride; (d) hydrogen telluride; e) bismuth (I...
by Layal Suboh 1I
Wed Oct 24, 2018 10:37 pm
Forum: *Shrodinger Equation
Topic: Solutions to the Schrodinger Equation
Replies: 1
Views: 100

Solutions to the Schrodinger Equation

Hello,

In one of the workshops, we discussed that the wave function is the solution to Schrodinger's equation. What exactly does that mean?
by Layal Suboh 1I
Wed Oct 24, 2018 10:35 pm
Forum: Trends in The Periodic Table
Topic: Ionization Energy
Replies: 6
Views: 112

Ionization Energy

Why does sulfur have a higher ionization energy than oxygen?
by Layal Suboh 1I
Wed Oct 24, 2018 10:32 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Subshells/Orbitals
Replies: 5
Views: 116

Subshells/Orbitals

Hi,

I know that the p subshell has 2px, 2py, and 2pz orbitals, what specific orbitals would the f subshell have?

Thanks!
by Layal Suboh 1I
Wed Oct 17, 2018 10:23 pm
Forum: *Shrodinger Equation
Topic: Schrodinger's Equation
Replies: 2
Views: 51

Schrodinger's Equation

Hello,

I'm having trouble understanding the significance of Schrodinger's equation. What exactly did it prove? Is there any equation related to it?


Thanks!
by Layal Suboh 1I
Wed Oct 17, 2018 10:21 pm
Forum: DeBroglie Equation
Topic: Measurable wavelike properties?
Replies: 2
Views: 53

Re: Measurable wavelike properties?

Hi!

You compare the wavelength you calculated to the speed of light (3.00*10^8 m/s). If the wavelength you calculated is greater than the speed of light, then it is unrealistic.

Hope this helps!
by Layal Suboh 1I
Wed Oct 17, 2018 10:19 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbitals
Replies: 3
Views: 36

Orbitals

Hello, I'm having a little difficulty understanding orbitals, specifically nodal planes. I know that the S-orbital does not have any nodal planes because it has one orbital, the P-orbital has one nodal plane, and the D-orbital has two nodal planes, but what are the exact functions and significance o...
by Layal Suboh 1I
Tue Oct 09, 2018 8:40 pm
Forum: Properties of Light
Topic: Photoelectric Effect
Replies: 2
Views: 30

Photoelectric Effect

Hello,

I'm a little confused about the process of the photoelectric experiment. I know that through this experiment, light was shown to be a particle, but how exactly was this experiment conducted so that the quantum mechanic description of light was proven?

Thank you!
by Layal Suboh 1I
Tue Oct 09, 2018 8:34 pm
Forum: Properties of Light
Topic: Atomic Spectra: Balmer and Lyman Series [ENDORSED]
Replies: 1
Views: 42

Atomic Spectra: Balmer and Lyman Series [ENDORSED]

Hello,

I'm confused about the applications of the Balmer and Lyman series. I understand that they deal with identifying spectral lines, but what exactly are they used to calculate, when do you use each of them, and how can you use both of the equations in the same problem?

Thanks!
by Layal Suboh 1I
Tue Oct 09, 2018 7:39 pm
Forum: Properties of Light
Topic: 1.A.11 Atomic Spectra
Replies: 1
Views: 22

1.A.11 Atomic Spectra

Hello, I'm having trouble with 1.A.11. The question is: 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.1). What is common to the lines within a series that makes grouping the...
by Layal Suboh 1I
Wed Oct 03, 2018 10:42 pm
Forum: Molarity, Solutions, Dilutions
Topic: Fundamentals E3- 7th Edition
Replies: 3
Views: 44

Re: Fundamentals E3- 7th Edition

Hello! First, in order to know how many atoms of Astatine you will need, you must calculate the mass of Gallium. You use the 9 atoms from the picture and avogadro's number to convert to moles, then the molar mass of Gallium to convert from moles to grams: Mass Gallium= (9 atoms) *(1 mol Ga/6.02*10^2...
by Layal Suboh 1I
Wed Oct 03, 2018 10:28 pm
Forum: Molarity, Solutions, Dilutions
Topic: G.25 Molarity of Solution after Diluting
Replies: 1
Views: 39

G.25 Molarity of Solution after Diluting

I'm having difficulty understanding question G. 25. I know that after doubling the volume the first time, the concentration will decrease to 0.5 mol.L^-1, but I don't know how to double the concentration 90 times without fully writing it out. Practitioners of the branch of a alternative medicine kno...
by Layal Suboh 1I
Tue Oct 02, 2018 5:12 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molarity and Dilution of a Solution Post Module Assessment Question 25
Replies: 5
Views: 88

Re: Molarity and Dilution of a Solution Post Module Assessment Question 25

First, you would need to convert grams of KMnO4 to moles: 5g KMnO4/158.04 g/mol= 0.0316 mol Then, you would need to calculate the initial molarity of this solution by dividing by the initial volume: 0.0316 mol KMn04/ 0.15 L= 0.2109 M KMnO4 Now, you use the MinitialVinitial=MfinalVfinal equation to f...

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