Search found 73 matches

by madisondesilva1c
Tue Feb 12, 2019 2:18 pm
Forum: Administrative Questions and Class Announcements
Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
Replies: 108
Views: 2389

Re: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)

Can someone explain how to solve 10 and 11? For 11, I used the mol(cv)(ln(t2/t1)) and am not getting the correct answer. Can someone please outline the steps to solve?
by madisondesilva1c
Tue Feb 12, 2019 1:13 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: deltaU=0
Replies: 3
Views: 13

Re: deltaU=0

Delta U is also 0 when there is no temperature change throughout the process.
by madisondesilva1c
Tue Feb 12, 2019 1:11 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Calorimeter - Type of System
Replies: 4
Views: 15

Calorimeter - Type of System

Is a calorimeter always isolated? Therefore, does delta U always equal work, assuming no heat can enter or leave the system?
by madisondesilva1c
Tue Feb 12, 2019 1:08 pm
Forum: Ideal Gases
Topic: pH and pOH
Replies: 16
Views: 70

Re: pH and pOH

It is always best to go with what is given, if OH is formed, then solve for pOH and then 14-pOH to find pH. If H+ is a product of the disassociation, then solve for pH and then use 14-pH if they are asking for pOH?
by madisondesilva1c
Tue Feb 12, 2019 1:07 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Acid Base
Replies: 2
Views: 13

Acid Base

Is is correct if given a pKa value, to the raise 10^ -pka to find the ka value, then use the expression for ka to solve for H+ concentration, x, to then take the -log of the H+ concentration, to then find the pH?

Are the pKA value and PH related through the Ka constant?
by madisondesilva1c
Fri Feb 08, 2019 9:17 pm
Forum: Phase Changes & Related Calculations
Topic: Signs in work equations
Replies: 1
Views: 18

Signs in work equations

Why is the work quantity in a isobaric process negative, in physics we have learned that w= +pdeltav... Can someone explain where the confusion comes from? Is this due to the fact we are using pressure external?
by madisondesilva1c
Fri Feb 08, 2019 9:04 pm
Forum: Phase Changes & Related Calculations
Topic: Negative work
Replies: 11
Views: 47

Re: Negative work

If the work is negative, how would the isobaric work equation change? Would the integral now be of a positive quantity instead of a negative one?
by madisondesilva1c
Fri Feb 08, 2019 8:59 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard Enthalpies
Replies: 1
Views: 9

Standard Enthalpies

Will Standard enthalpies be given on exam, or are there certain reactants and products that we should know specifically?
by madisondesilva1c
Mon Feb 04, 2019 10:17 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard / Formation / Reaction
Replies: 1
Views: 7

Standard / Formation / Reaction

Is there a way to know when to use each enthalpy value, if so can someone please summarize them? I know that one must use the standard enthalpy when solving for the enthalpy of the reaction, but what are the conditions for using the variation notations of enthalpy ie. reaction and formation enthalpy?
by madisondesilva1c
Mon Feb 04, 2019 10:12 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Closed System with a Piston
Replies: 2
Views: 12

Re: Closed System with a Piston

The piston either expands or minimizes the volume of your system. Therefore, the gas exerting work on a piston will increase the volume of the closed system. However if the environment does work on the system, the volume will decrease which is explained by the piston of the system compressing.
by madisondesilva1c
Mon Feb 04, 2019 10:10 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpies
Replies: 3
Views: 18

Bond Enthalpies

When figuring out what bonds to break to then reform, is it necessary to draw out the lewis structures? Are we expected to remember and draw out lewis structures in the way that we did in 14A?
by madisondesilva1c
Tue Jan 29, 2019 9:32 pm
Forum: Phase Changes & Related Calculations
Topic: Standard State
Replies: 6
Views: 26

Standard State

In lecture, Professor Lavelle talked about Standard States of pure substances and I was a bit confused on how people knew these so easily. Is this something we should memorize? Or are certain blocks of elements all in the same standard state?
by madisondesilva1c
Tue Jan 29, 2019 9:29 pm
Forum: Ideal Gases
Topic: Q and K
Replies: 8
Views: 36

Re: Q and K

As the Q and K value approach each other, does the rate at which products and reactants are converted ever decline or is the reaction a constant rate?
by madisondesilva1c
Tue Jan 29, 2019 9:25 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: open, closed, isolated
Replies: 4
Views: 49

open, closed, isolated

Is there any type of system that does not fit into this, has qualities of both open and closed say? If this is the case, how to you classify the system?
by madisondesilva1c
Wed Jan 23, 2019 10:06 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Ideal Gases
Replies: 2
Views: 28

Ideal Gases

What are some common examples of ideal gases being added to a reaction? I am having trouble imagining this happening but feel that a real world example may be able to help me understand this better.
by madisondesilva1c
Wed Jan 23, 2019 10:05 am
Forum: Ideal Gases
Topic: Units for concentration
Replies: 5
Views: 30

Units for concentration

Is it equivalent to write mol.L^-1 and M given that molarity is the moles of solute per liter?
by madisondesilva1c
Wed Jan 23, 2019 10:04 am
Forum: Student Social/Study Group
Topic: UA Worksheets
Replies: 2
Views: 68

UA Worksheets

I personally can not make all of the Worksheet guided UA sessions, but see they are posted online with solutions but no work. Is there anyway we could coordinate making a more detailed solution guide for students that cannot make the given session?
by madisondesilva1c
Fri Jan 18, 2019 3:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: When is X negligible.
Replies: 6
Views: 25

Re: When is X negligible.

X is negligible if the K value is below 10^-3. Therefore it would not change the initial concentration of the given reactant, so it is able to be disregarded in these cases.
by madisondesilva1c
Fri Jan 18, 2019 3:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Knowing Acids or Bases
Replies: 3
Views: 29

Knowing Acids or Bases

Is there a list somewhere that indicates strong bases and strong acids that we should know in order to properly execute skills on exams? Are there any biological compounds that we are also expected to know the chemical formula for?
by madisondesilva1c
Fri Jan 18, 2019 3:21 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Negative pH
Replies: 11
Views: 71

Re: Negative pH

If we encounter a problem where pH is negative, are we supposed to note that this is a super acid? Or is notation not required?
by madisondesilva1c
Mon Jan 14, 2019 12:19 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: ICE Table [ENDORSED]
Replies: 3
Views: 24

ICE Table [ENDORSED]

When computing the value of x in ICE tables, using the moles of products and reactants: do subscripts matter? Or does x strictly come from the stoichiometric coefficient?
by madisondesilva1c
Mon Jan 14, 2019 12:13 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: solids on the reactant side
Replies: 3
Views: 19

solids on the reactant side

If there is a solid for a reactant, do you assume that the solid is added to a flask containing water, therefore it really is in aqueous form. Dr. Lavelle mentioned in lecture that you assume the water is present, but are there any cases where assuming water is present incorrect and could lead you t...
by madisondesilva1c
Mon Jan 14, 2019 12:08 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Question 11.7 [ENDORSED]
Replies: 3
Views: 21

Re: Question 11.7 [ENDORSED]

Since the molecules of X and X2 do not change in quantity between flask 3 and 4, you must assume that the beaker was at equilibrium at flask 3, but not flask 2 because the quantities change between flask 2 and flask 3.
by madisondesilva1c
Fri Jan 11, 2019 10:43 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Minimum and Maximum
Replies: 2
Views: 19

Minimum and Maximum

Is there a maximum equilibrium constant that exists, and or a minimum? IF so how does this affect calculations of reactions?
by madisondesilva1c
Fri Jan 11, 2019 10:36 pm
Forum: Ideal Gases
Topic: Notation [ENDORSED]
Replies: 5
Views: 27

Notation [ENDORSED]

What is the correct notation for computing the partial pressure of gases, is it more correct to use brackets versus parenthesis when doing a problem of this sort?
by madisondesilva1c
Fri Jan 11, 2019 10:33 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Endothermic
Replies: 6
Views: 35

Re: Endothermic

During lecture, Dr. Lavelle noted that endothermic reactions require heat. Therefore, in order to proceed they will need heat due to requiring energy due to products from reactants having a positive enthalpy value. Looking at graphs of endothermic vs. exothermic could help you understand a visual.
by madisondesilva1c
Wed Dec 05, 2018 3:17 pm
Forum: Hybridization
Topic: Identifying Hybridization
Replies: 2
Views: 15

Identifying Hybridization

If there is an oxygen molecule with two hydrogen atoms bonded to it, but the lone pairs are not shown, do you assume the lone pairs still exist? Therefore would this oxygen atom have a hybridization of sp3?
by madisondesilva1c
Wed Dec 05, 2018 3:16 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: electron transitions
Replies: 2
Views: 17

electron transitions

There is a question on the modules that I cannot seem to get correct. If a electron is going from an energy level n to energy level n2 where n2 is less than n, the value of the change in energy will be negative. Is this always the case due to electron emitting energy to enter a lower energy level?
by madisondesilva1c
Wed Dec 05, 2018 3:14 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: pOH from pH
Replies: 2
Views: 21

pOH from pH

If you are given the pH of a solution, do you simply subtract the pH from 14 to find the pOH concentration value?
by madisondesilva1c
Fri Nov 30, 2018 3:38 pm
Forum: Electronegativity
Topic: Exceptions
Replies: 4
Views: 42

Re: Exceptions

I think there are a few exceptions that are not in perfect order of the trend, but relatively the most electronegative elements are on the top and to the right of the periodic table. Therefore, I feel that for exam purposes this trend should be sufficient and if there would be exception, or close di...
by madisondesilva1c
Fri Nov 30, 2018 3:35 pm
Forum: General Science Questions
Topic: Final Review
Replies: 4
Views: 78

Final Review

Are there any specific workshops that you have found very helpful or specific TA office hours that have really helped you grasp the material? I am trying to decide how to split up my time and want to attend the sessions that people have great past experiences with! Thanks!
by madisondesilva1c
Fri Nov 30, 2018 3:32 pm
Forum: Sigma & Pi Bonds
Topic: Drawing out Sigma and Pi Bonds
Replies: 1
Views: 38

Drawing out Sigma and Pi Bonds

How are the orbitals of d level supposed to be arranged when drawing out the sigma / pi bonds? Can the bonds happen between any two orbitals in the d orbitals or are there certain orientations which are more preferred?
by madisondesilva1c
Fri Nov 30, 2018 3:26 pm
Forum: Lewis Acids & Bases
Topic: Mixing up Lewis and Bronsted
Replies: 3
Views: 40

Mixing up Lewis and Bronsted

During lecture, Professor Lavelle began to what makes a Lewis base different than a Bronsted base and mentioned that Lewis bases are more general. What does general mean in this case?
by madisondesilva1c
Sat Nov 24, 2018 2:15 pm
Forum: Electronegativity
Topic: Arrows showing charge
Replies: 4
Views: 56

Re: Arrows showing charge

I believe that in discussion, we drew the arrows toward the net negative charge on the molecule, therefore where the stronger electronegativity is pulling the electrons, the arrow would point.
by madisondesilva1c
Sat Nov 24, 2018 2:13 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Slightly less than bond angles
Replies: 4
Views: 25

Re: Slightly less than bond angles

Are there other circumstances other than lone pairs that would make bond angles "slightly less than" or are these the cases that we are supposed to understand?
by madisondesilva1c
Sat Nov 24, 2018 2:11 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: double and triple bonds
Replies: 10
Views: 51

Re: double and triple bonds

A double or triple bond affects the shape in the VSEPR model the same way that a single bond affects the shape. The type of bond does not matter, but what matters is the number of regions of electron density, therefore one single bond is a region, one double bond is also one region. The fact that it...
by madisondesilva1c
Sun Nov 18, 2018 10:43 pm
Forum: Administrative Questions and Class Announcements
Topic: Workshops
Replies: 5
Views: 68

Workshops

Will there be the same workshops on the weekend after this upcoming holiday or are these canceled? If so is there extra practice we can see before the Test 3?
by madisondesilva1c
Sun Nov 18, 2018 10:41 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Cations vs anions
Replies: 3
Views: 51

Re: Cations vs anions

I am pretty sure that this question will be specific for the atoms involved in forming the cation or anion. Depending on the number of VE and then the bonds formed as well as the Lone pairs present, this will determine the bond angles, not the pure fact that the structure is a cation or anion. You m...
by madisondesilva1c
Mon Nov 12, 2018 8:02 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Dipole-Dipole v. Hydrogen Bonding
Replies: 2
Views: 24

Dipole-Dipole v. Hydrogen Bonding

I am confused how to differentiate whether a hydrogen bonding or a dipole-dipole bonding would be more likely or when one would occur versus the other since they have similar characteristics. When would a dipole-dipole occur over hydrogen bonds?
by madisondesilva1c
Mon Nov 12, 2018 7:55 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 3
Replies: 8
Views: 101

Test 3

Is Test 3 Cumulative of material before the midterm? And if so, where does the material that will be tested go up until from lecture?
by madisondesilva1c
Mon Nov 12, 2018 7:53 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 7th Ed. 2.7: Most important Lewis structure
Replies: 2
Views: 27

Re: 7th Ed. 2.7: Most important Lewis structure

I think that this means the lewis structure with the correct bond angles and the correct number of bonds to lone pairs. Sometimes the central atom will have a formal charge that is non-zero in order to satisfy the other atoms that is bonded to.
by madisondesilva1c
Tue Nov 06, 2018 2:49 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge of Oxygen
Replies: 6
Views: 67

Re: Formal Charge of Oxygen

I had this question as well and from other students I have heard that the oxygen is more electronegative therefore it prefers to have the negative charge compared to Nitrogen if one of them has to have it.
by madisondesilva1c
Tue Nov 06, 2018 2:41 pm
Forum: Ionic & Covalent Bonds
Topic: Covalent Bonds [ENDORSED]
Replies: 2
Views: 53

Covalent Bonds [ENDORSED]

How can one distinguish between polar covalent bonds and other forms of covalent bonds. Is there exceptions on the periodic table that would seemingly have a covalent bond but instead form ionic bonds?
by madisondesilva1c
Tue Nov 06, 2018 2:32 pm
Forum: Electronegativity
Topic: Electron affinity
Replies: 5
Views: 48

Re: Electron affinity

Electron affinity decreases down a group, and increases across a period. Therefore the trend is that higher up elements and further right elements have greater electron affinity. The trend is the same trend as ionization energy.
by madisondesilva1c
Tue Nov 06, 2018 2:30 pm
Forum: Octet Exceptions
Topic: Octet rule vs. Formal charge
Replies: 7
Views: 66

Re: Octet rule vs. Formal charge

From my knowledge and TA comments, I have the impression that the octet is the first thing to satisfy when drawing a lewis structure. Then once each octet is full, you can rearrange the electrons to create the closest formal charge to zero.
by madisondesilva1c
Fri Nov 02, 2018 10:29 am
Forum: Lewis Structures
Topic: Formal Charge Tricks
Replies: 5
Views: 49

Formal Charge Tricks

Even though there is a formal charge equation, I find myself coming up with the incorrect formal charge often after drawing the lewis structure and my error is aways in the 1/2(shared) portion of the calculation. Is there any helpful tips or tricks to correctly calculate formal charge or any common ...
by madisondesilva1c
Fri Nov 02, 2018 10:25 am
Forum: Octet Exceptions
Topic: The center atom
Replies: 20
Views: 202

Re: The center atom

You can figure out which would be the central atom due to the formation with the atom that will make the most bonds, or share the most electrons. You can always use the formula charge formula to access and see that placing O as the center atom would give a formal charge closest to or at the optimal ...
by madisondesilva1c
Fri Nov 02, 2018 10:23 am
Forum: Ionic & Covalent Bonds
Topic: Dipole
Replies: 4
Views: 27

Dipole

Todays lecture ended with the introduction of Dipole, how do you represent dipole with an arrow if two atoms are very similar in electronegativity? Will this ever be the case or will one always be more electronegative than the other?
by madisondesilva1c
Fri Nov 02, 2018 10:19 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Quantum Numbers related to Orbitals
Replies: 4
Views: 38

Quantum Numbers related to Orbitals

When determining the 4 quantum numbers that represent a wave function, is there a way to distinguish whether the 4th quantum number will be negative versus positive? Will you have to give two options for the quantum number sequence for each wave function indicating plus or minus 1/2 or is there a wa...
by madisondesilva1c
Fri Nov 02, 2018 10:17 am
Forum: Trends in The Periodic Table
Topic: Periodic trends
Replies: 4
Views: 27

Re: Periodic trends

I believe that we need to know the trends up to the lecture Wednesday therefore the ones that would be included are atomic radius, ionization energy, electronegativity, and electron affinity. I find it helpful to think about how the trends are related to each other and then you will have a better id...
by madisondesilva1c
Fri Nov 02, 2018 10:04 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Key Words
Replies: 4
Views: 69

Re: Key Words

I have found that within the text book the side notes help and if there is a topic that you are unsure of, there are many videos on youtube that focus on the keywords related to each topic which helps me to prepare for exams. I hope this helps!
by madisondesilva1c
Fri Nov 02, 2018 10:02 am
Forum: Administrative Questions and Class Announcements
Topic: Section
Replies: 2
Views: 41

Section

Will there be section held during the week of Thanksgiving? I have a section on tuesday but am trying to coordinate travel plans back home and am wondering if our discussion will meet during this week?
by madisondesilva1c
Fri Oct 26, 2018 12:35 pm
Forum: Lewis Structures
Topic: Periodic Table Trends
Replies: 3
Views: 32

Periodic Table Trends

Are there any exceptions in atomic radius, ionization energy, or electronegativity trends on the periodic table that would affect the orientation of the Lewis structure that do not follow the observed patterns learned in class?
by madisondesilva1c
Fri Oct 26, 2018 12:30 pm
Forum: Lewis Structures
Topic: Outer electrons
Replies: 2
Views: 36

Re: Outer electrons

Due to hunds rule, the orbitals of the atoms will fill based on that, therefore if you know what block the atom is located in you can figure out how the orbitals are going to fill with one electron in each orbital before filling both spots. You will have to back track the element based on location o...
by madisondesilva1c
Fri Oct 26, 2018 12:17 pm
Forum: Ionic & Covalent Bonds
Topic: periodic table
Replies: 4
Views: 57

Re: periodic table

metals tend to to lose electrons forming cations which are located on the left side of the periodic table. Non metals tend to gain electrons to fill their outer shell forming anions. These nonmetals are found toward the right side of periodic table.
by madisondesilva1c
Mon Oct 22, 2018 11:50 am
Forum: Properties of Electrons
Topic: Transitions
Replies: 3
Views: 82

Transitions

When an electron transitions from n=4 to n=2, or from any higher level to a lower level, should the change in energy by negative always?
by madisondesilva1c
Sun Oct 21, 2018 9:26 am
Forum: Properties of Light
Topic: TEST 2
Replies: 7
Views: 93

Re: TEST 2

I think that the same formula sheet that was given on test 1 will be used for test two which does have those constant provided. You may want to double check with your TA though!
by madisondesilva1c
Sat Oct 20, 2018 10:30 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Test Two
Replies: 2
Views: 31

Re: Test Two

I believe I would only study up to friday lecture. I think that outline two is continuous therefore we may have not finished the entire outline. As long as you know what he discussed about electron configuration on friday, I think that is most important.
by madisondesilva1c
Mon Oct 15, 2018 8:17 pm
Forum: DeBroglie Equation
Topic: Equivalent Equations
Replies: 2
Views: 31

Equivalent Equations

I know that during class we derived many equivalent equations using the aspects of the De Broglie Equation, is there certain indicators in questions or certain red flags that would better direct me figure out when you use certain versions of the De Broglie Equation?
by madisondesilva1c
Mon Oct 15, 2018 8:01 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Test Question
Replies: 3
Views: 65

Re: Test Question

On the cover page of the last exam, there were given constants, so that is a possibility. However, if you practice many practice problems and do the homework you will find that it is easy to remember the constants without too much effort, but just due to common use and application in this chapter! I...
by madisondesilva1c
Mon Oct 15, 2018 7:57 pm
Forum: SI Units, Unit Conversions
Topic: Frequency Units
Replies: 1
Views: 93

Frequency Units

When computing the frequency of waves or working with frequency, do you simply either use Hz or s^-1 depending on what other quantities you are working with at the moment? OR / AND is it more correct to leave the final computed frequency in Hz versus s^-1 or vice versa?
by madisondesilva1c
Mon Oct 15, 2018 7:53 pm
Forum: Properties of Electrons
Topic: Wave Properties of Electrons
Replies: 3
Views: 62

Wave Properties of Electrons

If electrons exhibit wave properties, is it possible for an electron to move from n=1 to n=3 while another moves from n=3 to n=1, therefore emitting no photon? Do we view this as a similar property such as destructive interference?
by madisondesilva1c
Fri Oct 12, 2018 3:07 pm
Forum: Properties of Electrons
Topic: Energy Levels
Replies: 4
Views: 183

Energy Levels

Can someone please explain why as one increases energy level, the distance between the levels decreases? E.g Energy level 3 and 4 are closer together than Energy level 2 and 3. Also, is there a way to calculate the energy of the photon emitted per transition of energy level?
by madisondesilva1c
Mon Oct 08, 2018 10:21 am
Forum: Significant Figures
Topic: Formula sheet?
Replies: 5
Views: 138

Re: Formula sheet?

I also asked my TA about the amount of molecules or compounds we should have memorized, and she said that basic diatomics and common ionic compounds are good to have memorized in order to successfully take the tests.
by madisondesilva1c
Mon Oct 08, 2018 10:20 am
Forum: Significant Figures
Topic: Formula sheet?
Replies: 5
Views: 138

Re: Formula sheet?

From asking around and from Dr. Lavelle, the only material provided for the test is a periodic table that gives the atomic mass and the symbol, the periodic table is a basic version and there is no other material that is allowed to be used during the test.
by madisondesilva1c
Mon Oct 08, 2018 10:13 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: molar mass
Replies: 2
Views: 59

Re: molar mass

Given the g within one molecule, you must multiply this by avogadros constant, 6.022 x 10^22 mol^-1. This comes from the idea that in order to find the mass of one molecule of anything, you take the molar mass of the substance from its composition, and then divide it by Avogadro's number to find the...
by madisondesilva1c
Mon Oct 08, 2018 10:05 am
Forum: SI Units, Unit Conversions
Topic: What is the notation for molar mass?
Replies: 15
Views: 389

Re: What is the notation for molar mass?

Yes. To clarify, you are correct. g/mol is equivalent to writing g.mol^-1. The power of negative 1 refers to the fact that the g/mol has moles within the denominator.
by madisondesilva1c
Mon Oct 08, 2018 8:24 am
Forum: Empirical & Molecular Formulas
Topic: Converting Units
Replies: 5
Views: 42

Re: Converting Units

In order to end up with the correct quantities, especially when using dimensional analysis it is much easier to convert all mL to L and all kg to g, in order to properly convert to mol.g-1 (etc.). Therefore I recommend converting units in the beginning so you do not have trouble canceling out units ...
by madisondesilva1c
Wed Oct 03, 2018 11:41 am
Forum: Molarity, Solutions, Dilutions
Topic: Dilutions
Replies: 3
Views: 76

Dilutions

If there are two compounds going into a solution, how do you calculate the molarity? Would it be correct to find the moles of the total solute (adding the moles of solute 1 and solute 2 together found from the molecular mass) and then proceed as normal?
by madisondesilva1c
Wed Oct 03, 2018 11:35 am
Forum: Limiting Reactant Calculations
Topic: Limiting Reactant Question
Replies: 2
Views: 36

Re: Limiting Reactant Question

I think potentially there could be a situation where two of the reactants may "run out" faster than the third, but out of these two, there would likely be a reactant that is "more limiting" in a sense that one reactant will still run out first. Therefore, you would continue the p...
by madisondesilva1c
Wed Oct 03, 2018 11:31 am
Forum: Molarity, Solutions, Dilutions
Topic: Units - L or mL? [ENDORSED]
Replies: 15
Views: 409

Re: Units - L or mL? [ENDORSED]

In order to compute dilations correctly, you will need to convert the volume of the given quantities to Liters, however if the known volumes in the question are given in milliliters then I would convert back to the unit of mL at the end of the answer. This is the format that the online Video Module ...
by madisondesilva1c
Sun Sep 30, 2018 3:23 pm
Forum: SI Units, Unit Conversions
Topic: How does grading for discussion posts work?
Replies: 73
Views: 1291

Re: How does grading for discussion posts work?

I think that either asking or answering a question is sufficient. You must interact three times per week with Chemistry Community according to the syllabus starting week 1 if there are 10 weeks in the quarter.
by madisondesilva1c
Sun Sep 30, 2018 3:21 pm
Forum: SI Units, Unit Conversions
Topic: Unit Conversions
Replies: 4
Views: 90

Unit Conversions

Within the SI Units, when converting is there a helpful reminder to remember the order of units, and is it sufficient to multiply to convert g to kg by multiplying by 10^-1 or must you simplify what the value truly is using the new units?

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