Search found 77 matches

by Nicolette_Canlian_2L
Tue Mar 12, 2019 9:44 pm
Forum: First Order Reactions
Topic: Integrated rate law confusion
Replies: 5
Views: 103

Re: Integrated rate law confusion

I don't believe there's a gain in using one over the other. It just depends on how you isolate the variables.
by Nicolette_Canlian_2L
Tue Mar 12, 2019 9:34 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: rate of disappearance
Replies: 3
Views: 76

rate of disappearance

How do we calculate a rate law if we are given the rate of disappearance instead of the rate of formation?
by Nicolette_Canlian_2L
Tue Mar 12, 2019 9:33 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Pre-equilibrium vs. steady-state
Replies: 4
Views: 67

Re: Pre-equilibrium vs. steady-state

the pre-equilibrium approach is a simpler way to get to the same solution with less complication.
by Nicolette_Canlian_2L
Tue Mar 05, 2019 9:14 pm
Forum: Calculating Work of Expansion
Topic: Keywords for each equation
Replies: 4
Views: 221

Re: Keywords for each equation

ChathuriGunasekera1D wrote:I know that I use the word "unique" to know if I have to use (-1/a)(dR/dt)

How do we apply the unique reaction rate?
by Nicolette_Canlian_2L
Tue Mar 05, 2019 9:07 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Equation to rate graph
Replies: 2
Views: 54

Re: Equation to rate graph

Since A is the reactant being used, its graph will be decreasing to a certain level and then stabilizes because equilibrium is reached. Since A has a coefficient of 2, the product B will be increasing/forming at a rate half of it. Product C will be forming at a rate triple the rate of A. Referencing...
by Nicolette_Canlian_2L
Tue Mar 05, 2019 8:57 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Finding Order for Each Reactant
Replies: 4
Views: 75

Re: Finding Order for Each Reactant

as long as the ratio of the the rates correspond to the concentrations that come along with them.
by Nicolette_Canlian_2L
Thu Feb 28, 2019 1:36 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cathode/Anode, +/-
Replies: 2
Views: 51

Re: Cathode/Anode, +/-

since this is a galvanic cell, we know that the reaction occurs spontaneously and energy is not required to start the reaction. You might be mixing this up with the concept of electrolytic cells brought up in lecture today because those require another source of energy for redox reactions to take pl...
by Nicolette_Canlian_2L
Thu Feb 28, 2019 1:24 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Electrode material in cell diagrams
Replies: 1
Views: 36

Re: Electrode material in cell diagrams

I believe that the solids must be placed on the outer part of the cell diagrams and the aqueous solutions are right next to the salt bridge. In regards to the liquid, I'm not too sure if it follows the same rules as solids.
by Nicolette_Canlian_2L
Tue Feb 26, 2019 12:42 am
Forum: Balancing Redox Reactions
Topic: redox potential
Replies: 1
Views: 33

redox potential

then is standard reduction potential equal to 0?
by Nicolette_Canlian_2L
Tue Feb 26, 2019 12:10 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Voltaic vs galvanic cell
Replies: 2
Views: 45

Re: Voltaic vs galvanic cell

You might be thinking about the difference between an electrolytic cell and galvanic cell. An electrolytic cell is one in which delta G is positive and the standard cell potential is negative. In a galvanic cell, delta G is negative and the standard cell potential is positive. galvanic=spontaneous a...
by Nicolette_Canlian_2L
Tue Feb 26, 2019 12:06 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Pt(s) in cell diagram
Replies: 4
Views: 69

Re: Pt(s) in cell diagram

the metal conductor is always added to the outer part of the cell diagram.
by Nicolette_Canlian_2L
Fri Feb 22, 2019 1:19 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Question 9.63
Replies: 2
Views: 46

Re: Question 9.63

I'm having trouble with this one as well. What is the relationship between gibbs free energy and stability? Do we have to consider the other thermodynamic terms as well?
by Nicolette_Canlian_2L
Wed Feb 20, 2019 8:26 pm
Forum: Balancing Redox Reactions
Topic: Salt Bridge
Replies: 4
Views: 109

Re: Salt Bridge

I believe they have the same function, but the shapes of them are what differ.
by Nicolette_Canlian_2L
Wed Feb 20, 2019 8:23 pm
Forum: Ideal Gases
Topic: units
Replies: 15
Views: 371

Re: units

You would only use bar if the question were to ask, for example, the pressure of the gas at equilibrium.
by Nicolette_Canlian_2L
Thu Feb 14, 2019 10:50 pm
Forum: Phase Changes & Related Calculations
Topic: Phase Change Diagram of Water
Replies: 6
Views: 128

Re: Phase Change Diagram of Water

additional energy is required to change water from its boiling point to steam. Extra heat will cause the boiled water to reach vapor and burn more.
by Nicolette_Canlian_2L
Thu Feb 14, 2019 10:42 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Ideal gases
Replies: 4
Views: 105

Re: Ideal gases

rather than just using the ideal gas constant, you use 5/2R and 3/2R as the constants depending on whether volume or pressure is constant.
by Nicolette_Canlian_2L
Wed Feb 06, 2019 10:53 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: deltaU=3/2nRdeltaT
Replies: 1
Views: 56

Re: deltaU=3/2nRdeltaT

I think we're going to cover this further in class, but it seems to be related to the linearity of a molecule.
by Nicolette_Canlian_2L
Wed Feb 06, 2019 10:50 pm
Forum: Calculating Work of Expansion
Topic: Degeneracy
Replies: 6
Views: 142

Re: Degeneracy

is there a relationship between degeneracy and entropy?
by Nicolette_Canlian_2L
Wed Feb 06, 2019 10:41 pm
Forum: Calculating Work of Expansion
Topic: 6th edition 8.31
Replies: 3
Views: 75

Re: 6th edition 8.31

I was stuck on the same question. So we have to convert the given mass of the krypton gas into moles and work from there?
by Nicolette_Canlian_2L
Thu Jan 31, 2019 1:43 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Perfect system
Replies: 3
Views: 91

Re: Perfect system

I'm not entirely sure, but I'm assuming since there aren't any external factors affecting the course of the reaction, there won't be any so-called errors in the experiment.
by Nicolette_Canlian_2L
Thu Jan 31, 2019 1:38 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: closed vs isolated
Replies: 14
Views: 199

Re: closed vs isolated

A closed system is also sealed, but the transfer of energy is what is observed. When comparing open and closed systems, we observe changes in matter.
by Nicolette_Canlian_2L
Thu Jan 31, 2019 1:37 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Method 2: Using bond enthalpies
Replies: 3
Views: 59

Re: Method 2: Using bond enthalpies

Could you find the difference of the number of bonds broken and the total number of bonds formed? I remember learning it this way in high school, but I'm not too sure.
by Nicolette_Canlian_2L
Fri Jan 25, 2019 10:49 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Change in temp
Replies: 3
Views: 87

Re: Change in temp

Since the reaction requires heat, decreasing the temp would make it difficult for the reaction to take place. For this reason, the reaction shifts towards the reactants to form more heat necessary to carry out the reaction.
by Nicolette_Canlian_2L
Thu Jan 24, 2019 12:37 am
Forum: Ideal Gases
Topic: Ice Table with quadratic equation on bottom
Replies: 3
Views: 78

Re: Ice Table with quadratic equation on bottom

Does this reaction only have one product in either the gaseous or aqueous state?
by Nicolette_Canlian_2L
Thu Jan 24, 2019 12:35 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: help on last module!
Replies: 2
Views: 72

Re: help on last module!

I have the same question. Does it have anything to do with the volume increasing since liquid water is placed into the reaction? Would this therefore decrease the pressure of the system? I don't understand how water at its liquid state would be incorporated into the equilibrium constant.
by Nicolette_Canlian_2L
Thu Jan 24, 2019 12:33 am
Forum: Ideal Gases
Topic: Ideal Gas Law
Replies: 7
Views: 155

Re: Ideal Gas Law

It can be used to solve for any of the variables in the equation. Temperature is constant, so it'll be used to solve for the other conditions.
by Nicolette_Canlian_2L
Thu Jan 17, 2019 1:57 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Conjugates
Replies: 4
Views: 69

Re: Conjugates

The conjugate acid to the base will be the molecule that has gained a proton. The conjugate base to an acid will be the molecule that loses a proton.
HCOOH + H2O----HCOO[-] + H3O+
HCOOH is the acid and HCOO[-] is the conjugate base.
by Nicolette_Canlian_2L
Thu Jan 17, 2019 1:50 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Percent Ionization
Replies: 3
Views: 49

Re: Percent Ionization

you can use a quadratic or maybe even a cubic function if it comes down to that. Checking the percent ionization does save time though.
by Nicolette_Canlian_2L
Tue Jan 15, 2019 1:18 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: stability
Replies: 3
Views: 79

stability

in the 7th edition 5I.13, the questions asks us to find the equilibrium composition of of the mixtures when 2.0mmol Cl2 and 2.0mmol F2 are placed in different 2.0L vessels at 1000. K. Part C asks which is more thermodynamically stable. How do we determine the stability? Is it based on the equilibriu...
by Nicolette_Canlian_2L
Thu Jan 10, 2019 4:38 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: H2O
Replies: 5
Views: 76

Re: H2O

Aurbal Popal wrote:Wait do we just ignore water as a liquid if we are doing partial pressures (Kp) or does this apply when we do Kc as well?

I believe so, since we only include gases and aqueous solutions in K expressions.
by Nicolette_Canlian_2L
Wed Jan 09, 2019 1:00 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 7th edition 5G.5
Replies: 3
Views: 58

Re: 7th edition 5G.5

I second this!! Also, how did you figure out part a and b? How do we determine equilibrium by looking at the molecules?
by Nicolette_Canlian_2L
Wed Jan 09, 2019 12:03 am
Forum: Ideal Gases
Topic: pressure notation
Replies: 2
Views: 71

pressure notation

what does P^o represent?
by Nicolette_Canlian_2L
Tue Jan 08, 2019 11:27 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: pressure when given temp and time
Replies: 1
Views: 43

pressure when given temp and time

I'm not sure how to approach this problem. In the 7th edition, it is part of the self test 3B.2A. A rigid oxygen tank stored outside a building has a pressure of 20.00atm at 6:00am, when the temp is 10 degrees celsius. What will be the pressure in the tank at 6:00pm, when the temp is 30. degrees cel...
by Nicolette_Canlian_2L
Thu Dec 06, 2018 3:33 am
Forum: Lewis Acids & Bases
Topic: HCl vs. HI
Replies: 7
Views: 129

Re: HCl vs. HI

You can also determine this based on the atomic radius. Since I has a larger atomic radius than Cl, it is easier for the I atom to release H+ than it is for Cl because of the looser pull of the electrons towards the central atom.
by Nicolette_Canlian_2L
Thu Dec 06, 2018 12:21 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape
Replies: 4
Views: 78

Re: Molecular Shape

I believe its geometry comes about because of the lone pair on the iodine. If it were trigonal bipyramidal, there would not be any lone pairs on the central atom.
by Nicolette_Canlian_2L
Thu Dec 06, 2018 12:18 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Sig Figs for pH
Replies: 3
Views: 83

Re: Sig Figs for pH

Are the sig fig rules different when applied to pH, then?
by Nicolette_Canlian_2L
Thu Dec 06, 2018 12:17 am
Forum: Naming
Topic: Tricks/cheat sheet
Replies: 3
Views: 104

Re: Tricks/cheat sheet

I recommend making flashcards and referencing the sheet Dr.Lavelle has posted on the class website.
by Nicolette_Canlian_2L
Thu Dec 06, 2018 12:16 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Net Dipole
Replies: 3
Views: 81

Re: Net Dipole

When determining dipole moments, consider the electronegativity of the atoms in the molecule and check for any lone pairs on the central atom.
by Nicolette_Canlian_2L
Sat Dec 01, 2018 12:38 pm
Forum: Resonance Structures
Topic: Resonance
Replies: 4
Views: 229

Re: Resonance

In the case of the sulfate ion, sulfur and the oxygens that are double-bonded to the sulfur will have formal charges of zero. The oxygens that are single-bonded to the sulfur will each have a formal charge of negative one, adding up to negative two. This contributes to the sulfate ion's charge of ne...
by Nicolette_Canlian_2L
Sat Dec 01, 2018 12:32 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone pairs
Replies: 4
Views: 129

Re: Lone pairs

Lone pairs cause repulsion between the the atoms bonded to the central atom. They create a smaller bond angle between the atoms because the atoms will be pushed down.
by Nicolette_Canlian_2L
Sat Dec 01, 2018 12:27 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar Molecules
Replies: 12
Views: 186

Re: Polar Molecules

You can check the number of lone pairs on the central atom and try to determine the shape of the molecule to find the overall dipole moment (if it exists).
by Nicolette_Canlian_2L
Mon Nov 26, 2018 9:28 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Homework question
Replies: 4
Views: 59

Re: Homework question

You want to check the formal charges of the atoms in the molecule, so that explains the bonding of xenon and fluorine in this example.
by Nicolette_Canlian_2L
Sat Nov 24, 2018 12:22 am
Forum: Hybridization
Topic: Octet Expansion and d-Orbitals
Replies: 8
Views: 179

Re: Octet Expansion and d-Orbitals

So is any element in the first 3 groups without a d-orbital in its shell unable to fulfill the octet rule? Under my current understanding, I believe any element in the first three groups don't have to meet the octet rule of maximum 8 electrons, it can exceed the octet rule since it has access to th...
by Nicolette_Canlian_2L
Thu Nov 22, 2018 10:43 am
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR
Replies: 3
Views: 134

Re: VSEPR

Does it only apply to gases?
by Nicolette_Canlian_2L
Thu Nov 22, 2018 10:27 am
Forum: Hybridization
Topic: Octet Expansion and d-Orbitals
Replies: 8
Views: 179

Re: Octet Expansion and d-Orbitals

So is any element in the first 3 groups without a d-orbital in its shell unable to fulfill the octet rule?
by Nicolette_Canlian_2L
Thu Nov 22, 2018 10:26 am
Forum: Determining Molecular Shape (VSEPR)
Topic: molecular vs electron geometry
Replies: 2
Views: 33

Re: molecular vs electron geometry

does this question apply to the example we did in lecture in which XeF4 was defined as having octahedral geometry and square planar shape? I was confused by this.
by Nicolette_Canlian_2L
Thu Nov 15, 2018 6:20 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: hydrogen bonding
Replies: 11
Views: 243

Re: hydrogen bonding

^Exactly. Higher melting points indicate more stability so this explains the example given in class: GC base pairs in DNA are more stable than AT base pairs. So does this mean GC base pairs have stronger bonds than AT base pairs? Yes, because G-C base pairs have three hydrogen bonds rather than two...
by Nicolette_Canlian_2L
Tue Nov 13, 2018 8:47 pm
Forum: Electronegativity
Topic: Polarity
Replies: 3
Views: 79

Re: Polarity

is the polarity determined only by the electronegativity of an atom, or are there other factors that contribute?
by Nicolette_Canlian_2L
Tue Nov 13, 2018 8:44 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: hydrogen bonding
Replies: 11
Views: 243

Re: hydrogen bonding

Alexa_Henrie_3B wrote:^Exactly. Higher melting points indicate more stability so this explains the example given in class: GC base pairs in DNA are more stable than AT base pairs.

So does this mean GC base pairs have stronger bonds than AT base pairs?
by Nicolette_Canlian_2L
Tue Nov 13, 2018 8:42 pm
Forum: Lewis Structures
Topic: Lewis Structure
Replies: 3
Views: 84

Re: Lewis Structure

I am confused on this lewis structure in general. Is the octet rule for chlorine not supposed to be fulfilled?
by Nicolette_Canlian_2L
Mon Nov 12, 2018 12:35 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape
Replies: 5
Views: 112

Re: Molecular Shape

I think there might also be a chart to help memorize the different shapes of molecules. It should list the number of bonded and lone pairs, which determine the molecular shape.
by Nicolette_Canlian_2L
Mon Nov 12, 2018 12:31 am
Forum: Dipole Moments
Topic: Dipole Moments [ENDORSED]
Replies: 10
Views: 232

Re: Dipole Moments [ENDORSED]

What exactly is a dipole moment? I know it was to do with charges, but is there a deeper explanation?
by Nicolette_Canlian_2L
Mon Nov 05, 2018 11:22 pm
Forum: Lewis Structures
Topic: Lewis Structure for N2O
Replies: 7
Views: 162

Re: Lewis Structure for N2O

why is nitrogen more electronegative than oxygen? Does it relate to the number of electrons filling the d-orbital?
by Nicolette_Canlian_2L
Mon Nov 05, 2018 11:20 pm
Forum: Resonance Structures
Topic: Bond Lengths
Replies: 7
Views: 219

Re: Bond Lengths

I don't understand where the 124 is coming from. Is there a calculation that needs to be done to come to this bond length value?
by Nicolette_Canlian_2L
Fri Nov 02, 2018 11:03 pm
Forum: Trends in The Periodic Table
Topic: Difference between Atomic Radius and Ionic Radius
Replies: 2
Views: 322

Re: Difference between Atomic Radius and Ionic Radius

The periodic trends of atomic radius follow for both ionic and covalent radii also. The bonding types might be different, but the ionization energy will still be greater for an atom further across a period and smaller for an atom lower in a group.
by Nicolette_Canlian_2L
Mon Oct 29, 2018 11:39 pm
Forum: DeBroglie Equation
Topic: Uncertainty
Replies: 4
Views: 181

Re: Uncertainty

I believe that the rule applies to objects that are smaller than 10^-18. I am not confident on this though, so if anyone else knows, that would be helpful!
by Nicolette_Canlian_2L
Mon Oct 29, 2018 11:35 pm
Forum: Lewis Structures
Topic: Delocalized Electrons
Replies: 5
Views: 94

Re: Delocalized Electrons

This will also relate to sigma and pi bonds, which we will learn about later. It will make more sense when applied to these concepts.
by Nicolette_Canlian_2L
Sat Oct 27, 2018 9:38 pm
Forum: Trends in The Periodic Table
Topic: Ionization Energy and Electron Affinity
Replies: 9
Views: 520

Re: Ionization Energy and Electron Affinity

Yukta Italia 3I wrote:Why are electrons that are further away from the nucleus easier to remove?

The inner electrons shield the other electrons, causing a decrease in the effective nuclear charge. This allows for an easier removal of a valence electron.
by Nicolette_Canlian_2L
Sun Oct 21, 2018 7:33 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Question 1.15 sixth edition
Replies: 10
Views: 166

Re: Question 1.15 sixth edition

why is the energy level of 102.6 nm 1? This is what i don't understand. Even when I see pictures of the spectroscopy with the Lyman series, I notice that 102.6 is one of the values next to a line, but I'm not sure how to identify that it is n=1 . I just realized that we have to use an equation to s...
by Nicolette_Canlian_2L
Sun Oct 21, 2018 7:07 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: test #2
Replies: 4
Views: 71

Re: test #2

I believe it should still be 40 points like the last one.
by Nicolette_Canlian_2L
Sun Oct 21, 2018 7:03 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Lecture Question on Orbitals
Replies: 4
Views: 104

Re: Lecture Question on Orbitals

exactly what do all the quantum numbers represent?
by Nicolette_Canlian_2L
Tue Oct 16, 2018 9:11 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Question 1.15 sixth edition
Replies: 10
Views: 166

Re: Question 1.15 sixth edition

why is the energy level of 102.6 nm 1?
by Nicolette_Canlian_2L
Tue Oct 16, 2018 8:46 pm
Forum: Properties of Light
Topic: 7th Edition 1A.3
Replies: 4
Views: 78

Re: 7th Edition 1A.3

what is the relationship between energy and frequency?
by Nicolette_Canlian_2L
Tue Oct 16, 2018 8:36 pm
Forum: Properties of Light
Topic: still don't uderrsatnd what a photon is [ENDORSED]
Replies: 20
Views: 411

Re: still don't uderrsatnd what a photon is [ENDORSED]

is there a certain constant that comes along with the size of a photon?
by Nicolette_Canlian_2L
Tue Oct 09, 2018 5:25 pm
Forum: SI Units, Unit Conversions
Topic: Avogadro's Number [ENDORSED]
Replies: 11
Views: 426

Re: Avogadro's Number [ENDORSED]

Does Avogadro's number include units, or do we use the number alone?
by Nicolette_Canlian_2L
Tue Oct 09, 2018 5:08 pm
Forum: Limiting Reactant Calculations
Topic: HW1 M19
Replies: 3
Views: 271

Re: HW1 M19

Do we have to first convert the grams of each compound into moles and then find the mass of the individual elements from there?
by Nicolette_Canlian_2L
Tue Oct 09, 2018 5:01 pm
Forum: Significant Figures
Topic: Sig Fig zero rules
Replies: 7
Views: 271

Re: Sig Fig zero rules

and just another sig fig rule is that if the decimal is 0.405, you would round your answer to 0.400 when needing 3 sig figs. When the last digit ends in five, would want to round the digit prior to it to the nearest even number.
by Nicolette_Canlian_2L
Sun Oct 07, 2018 10:22 pm
Forum: Limiting Reactant Calculations
Topic: Mole Ratios Within the Conversion
Replies: 3
Views: 73

Re: Mole Ratios Within the Conversion

Just by looking at the equation of a chemical reaction, how can we determine which reactant is limiting?
by Nicolette_Canlian_2L
Sun Oct 07, 2018 10:15 pm
Forum: Molarity, Solutions, Dilutions
Topic: dilutions? [ENDORSED]
Replies: 5
Views: 135

Re: dilutions? [ENDORSED]

Sometimes the problem won't directly give you the initial molarity, so you might have to convert the given mass of solute to moles. Then divide by the volume of the solvent to find the initial molarity.
by Nicolette_Canlian_2L
Tue Oct 02, 2018 7:56 pm
Forum: SI Units, Unit Conversions
Topic: Fundamentals Problem E15
Replies: 4
Views: 155

Re: Fundamentals Problem E15

I first found the molar mass of the (OH)2, and then I subtracted this value from the given molar mass. This will give you the molar mass of the metal. Then, you must add the molar mass of the metal to the the molar mass of the sulfide ion to find the mass of the sulfide of this metal. Let me know if...
by Nicolette_Canlian_2L
Tue Oct 02, 2018 7:44 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Question E1(6th Edition)
Replies: 7
Views: 218

Re: Question E1(6th Edition)

Can we leave our answer in pm, or do we have to convert it to km?
by Nicolette_Canlian_2L
Sun Sep 30, 2018 11:38 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Fundamental E11
Replies: 2
Views: 1133

Re: Fundamental E11

The method I used to solve part a is by multiplying the mass of each with its correlating percentage of abundance and then added these products together.
m=0.0742(9.988x10^-24g)+0.9258(1.165x10^-23g)
m=1.153x10^-23g
Then I multiplied the sum of those two with Avogadro's constant and got 6.94g/mol
by Nicolette_Canlian_2L
Sun Sep 30, 2018 10:58 pm
Forum: Empirical & Molecular Formulas
Topic: Problem E5
Replies: 6
Views: 1118

Re: Problem E5

How do you go about solving part b? Do I use the same equation I used for part A?
by Nicolette_Canlian_2L
Sun Sep 30, 2018 10:35 pm
Forum: Empirical & Molecular Formulas
Topic: Formula Units vs. Molecules [ENDORSED]
Replies: 1
Views: 125

Re: Formula Units vs. Molecules [ENDORSED]

I believe molecular unit refers to the mass of an entire molecular compound and formula unit refers to the mass of an ionic compound. These are defined on page F42 in the 7th edition book.
by Nicolette_Canlian_2L
Sun Sep 30, 2018 8:03 am
Forum: Molarity, Solutions, Dilutions
Topic: Study Module Post-assessment Question
Replies: 5
Views: 173

Re: Study Module Post-assessment Question

I am confused on this problem as well. I'm unsure of what the initial and final volumes are. I used the 15L as the initial volume and when it came to the final volume I was not sure whether to use the 0.02L or 0.250L.
by Nicolette_Canlian_2L
Fri Sep 28, 2018 1:07 pm
Forum: Limiting Reactant Calculations
Topic: Is there a specific way to solve limiting reactant problems?
Replies: 4
Views: 159

Re: Is there a specific way to solve limiting reactant problems?

The method I use to solve limiting reactant problems is by converting the reactants' mass into moles. I don't think this is impossible because once you have converted the reactants into moles, you compare the two. The reactant with less moles is the limiting reactant. I believe you can solve these k...

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