memorize this (it hasnt been on the sheet)
[A]t=[A]o -kt
Search found 62 matches
- Fri Mar 15, 2019 1:33 pm
- Forum: General Rate Laws
- Topic: Final Equations
- Replies: 4
- Views: 443
- Fri Mar 15, 2019 1:28 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: When to use Quadratic equation
- Replies: 10
- Views: 6430
Re: When to use Quadratic equation
Does anyone have an example of this either from a book or a review session that goes step by step? thank u
- Fri Mar 15, 2019 1:27 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Buffers
- Replies: 4
- Views: 774
Re: Buffers
Yes the acid/base comes from the salt!
- Fri Mar 15, 2019 1:26 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: strong and weak acids
- Replies: 5
- Views: 743
Re: strong and weak acids
the more H3O+ ions there are the stronger the acid, so lower H3O+ ions means higher pH. (It's completely based on the H3O+ ions)
- Fri Mar 15, 2019 1:25 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Units
- Replies: 6
- Views: 956
Re: Units
No units for any of the equilibrium constants.
- Fri Mar 15, 2019 1:22 pm
- Forum: Ideal Gases
- Topic: atm vs. bar?
- Replies: 25
- Views: 2820
Re: atm vs. bar?
when calculating for R just use the 8.314 value
- Fri Mar 15, 2019 1:20 pm
- Forum: Ideal Gases
- Topic: overall grade points
- Replies: 2
- Views: 343
Re: overall grade points
the C- is a 50% but it depends on the class average that it is scaled to that.
- Fri Mar 15, 2019 1:18 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: instantaneous and unique rate
- Replies: 6
- Views: 1196
Re: instantaneous and unique rate
The unique rate has more to do with their relationship with each other like a product with a reactant.
The instantaneous rate is the tangent line when their is a change.
The instantaneous rate is the tangent line when their is a change.
- Fri Mar 15, 2019 1:16 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Initial Rates given in mmmol
- Replies: 2
- Views: 597
Re: Initial Rates given in mmmol
i always convert back to mol because that's like the official units
- Fri Mar 15, 2019 1:15 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Units of k
- Replies: 7
- Views: 1015
Re: Units of k
they are different depending on the order.
so the 1st only has s^-1
2nd: mol*L^-1*s^-1
3rd: mol^2 *L^-2 *s^-2
so the 1st only has s^-1
2nd: mol*L^-1*s^-1
3rd: mol^2 *L^-2 *s^-2
- Fri Mar 15, 2019 1:13 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Rate vs. Initial Rate
- Replies: 4
- Views: 755
Re: Rate vs. Initial Rate
initial rate is the one thats usually given but if the rate in general is given to you then you use the equation to do (k*any concentration that you are at) , versus initial has to do with the concentration in the beginning.
- Wed Feb 20, 2019 1:48 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: What is pKa and Ka exactly?
- Replies: 16
- Views: 24772
Re: What is pKa and Ka exactly?
the larger the Ka, the stronger the acid.
- Wed Feb 20, 2019 1:47 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Autoprotolysis
- Replies: 4
- Views: 691
Re: Autoprotolysis
it just means that in this example water can be an acid and a base. With this said, some of them would give away their H+ and become OH- and the one receiving the proton would become H3O+ .
- Wed Feb 20, 2019 1:45 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: ignoring x validity
- Replies: 6
- Views: 838
Re: ignoring x validity
But are they going to give us a problem that is x^3?
- Wed Feb 20, 2019 1:45 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Direction of a Reaction
- Replies: 8
- Views: 937
Re: Direction of a Reaction
if Q>K , the reaction moves to the reactants.
if Q<K, the reaction moves to the products
if Q<K, the reaction moves to the products
- Wed Feb 20, 2019 1:41 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Le Chatelier's Principle
- Replies: 11
- Views: 1508
Re: Le Chatelier's Principle
how do you calculate the partial pressure? and how does that relate to concentration?
- Wed Feb 20, 2019 1:38 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: When does delta U equal zero?
- Replies: 17
- Views: 8218
Re: When does delta U equal zero?
if the problem states that it is isothermal, q=0 and q=-w, since delta U = q+w, 0+0=0
- Wed Feb 20, 2019 1:36 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Is there a significance with 298 degrees Kelvin?
- Replies: 5
- Views: 7436
Re: Is there a significance with 298 degrees Kelvin?
Yes, 298 Degrees Kelvin is the standard for ideal gas.
- Wed Feb 20, 2019 1:35 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: equations for q
- Replies: 9
- Views: 840
Re: equations for q
if its just the C(delta) T, you are already included the amount of moles, instead of adding it in the beginning.(aka when you only have one mole)
- Wed Feb 20, 2019 1:34 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Endothermic and Exothermic Graphs
- Replies: 3
- Views: 1056
Re: Endothermic and Exothermic Graphs
But keep in mind that delta H has a lot to do with this. and when measuring delta H you would measure from the beginning to the end state. (even if it does a big loop up, its just beginning and end result)
- Wed Feb 20, 2019 1:32 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Most stable form?
- Replies: 4
- Views: 496
Re: Most stable form?
What are the main things you would look for to determine its in the most stable form?
- Wed Feb 20, 2019 1:30 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Using R
- Replies: 10
- Views: 961
Re: Using R
You usually use R=8.314 , but the other values for R are given on the equation sheet.
- Wed Feb 20, 2019 1:29 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Cp vs Cv
- Replies: 7
- Views: 1054
Re: Cp vs Cv
There are some times that they give you the C or heat capacity and you would just multiply this C by the number of moles.
- Wed Feb 20, 2019 1:27 pm
- Forum: Phase Changes & Related Calculations
- Topic: Isothermal
- Replies: 9
- Views: 1076
Re: Isothermal
for the most part it should state that it is isothermal or that the temperature is constant.
- Tue Feb 19, 2019 9:17 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Work done vs work on system
- Replies: 18
- Views: 3786
Re: Work done vs work on system
Think about it in terms of yourself.
if you're doing a workout, you lose energy.
But if someone else is doing it, you're positive energy.
if you're doing a workout, you lose energy.
But if someone else is doing it, you're positive energy.
- Tue Feb 19, 2019 9:14 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Final exam
- Replies: 8
- Views: 884
Re: Final exam
He will also give a ton of review sessions for the final in week 10 .
- Tue Feb 19, 2019 9:14 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: R constants
- Replies: 40
- Views: 2111
Re: R constants
The best way to determine this is just to look if you can cancel out all the units.
- Tue Feb 19, 2019 9:13 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Assume Ideal Behavior
- Replies: 3
- Views: 1010
Re: Assume Ideal Behavior
This "assume ideal behavior" just means you can us PV=nRT equation
- Tue Feb 19, 2019 9:10 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: constant C
- Replies: 7
- Views: 1005
Re: constant C
just C is the heat capacity. C subunit P, is the heat capacity at the constant pressure. C subunit V is the heat capacity at constant volume.
- Tue Feb 19, 2019 9:08 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Midterm Grades
- Replies: 35
- Views: 2640
Re: Midterm Grades
the tests themselves are not curve. but as long as you get 250 points out of 500 points in the whole quarter you get a C-
- Fri Dec 07, 2018 11:39 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Ordering Polarizability and Polarizing Power
- Replies: 4
- Views: 2050
Re: Ordering Polarizability and Polarizing Power
you determine the order based on the amount of electrons and the size of the atom. for Anions you are looking for the one that is more negativity. and for the cations you are looking for the most positive.
- Fri Dec 07, 2018 11:34 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone Pairs
- Replies: 5
- Views: 527
Lone Pairs
Only the lone pairs on the central atom affect the shape right? not the lone pairs on the other ones?
- Fri Dec 07, 2018 11:31 am
- Forum: Hybridization
- Topic: Sigma bonds
- Replies: 9
- Views: 841
Re: Sigma bonds
marg44 wrote:For these sigma and pi bonds, is one bond stronger than the other? Or are they of equal strength?
Sigma bonds are stronger and pi bonds are weaker.
- Fri Dec 07, 2018 11:26 am
- Forum: Bond Lengths & Energies
- Topic: Bond strength & resonance structures
- Replies: 2
- Views: 671
Bond strength & resonance structures
Can someone explain the correlation between the bond strength and resonance structures?
- Fri Dec 07, 2018 11:21 am
- Forum: *Stereochemistry
- Topic: What's a stereocenter?
- Replies: 5
- Views: 2207
Re: What's a stereocenter?
if it is on the final, is it used as a concept question or something more than that?
- Fri Dec 07, 2018 11:16 am
- Forum: *Shrodinger Equation
- Topic: Shrodinger Equation meaning
- Replies: 1
- Views: 419
Shrodinger Equation meaning
Can someone re explain this concept briefly ? i know we are not doing calculations (just conceptual) right?
- Fri Dec 07, 2018 11:13 am
- Forum: Bond Lengths & Energies
- Topic: intermolecular forces
- Replies: 1
- Views: 589
intermolecular forces
How do you determine what inter molecular forces could be present in a molecule?
- Fri Dec 07, 2018 11:10 am
- Forum: Calculating the pH of Salt Solutions
- Topic: pH on final
- Replies: 5
- Views: 1407
pH on final
what are some questions that could be asked on the final using pH?
- Fri Dec 07, 2018 11:08 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Strong Acids [ENDORSED]
- Replies: 1
- Views: 280
Strong Acids [ENDORSED]
Can someone name all the strong acids? I know that it's a short list.
- Tue Nov 13, 2018 5:43 pm
- Forum: Resonance Structures
- Topic: Resonance Structures
- Replies: 6
- Views: 820
Re: Resonance Structures
That makes so much more sense! thank you!
- Tue Nov 13, 2018 5:39 pm
- Forum: Hybridization
- Topic: How to Determine
- Replies: 12
- Views: 1076
Re: How to Determine
Can someone give a concrete example that would help better visualize this? thanks
- Tue Nov 13, 2018 5:36 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 5
- Views: 716
Re: Bond Angles
If you do draw them out, I would recommend explicitly writing the degrees somewhere just to be safe. This will also show your TA that you know what bond angle is actually there without having to actually draw out a 109.5 degrees vs a 120 degree angle.
- Tue Nov 13, 2018 5:29 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Biological Activity
- Replies: 3
- Views: 355
Re: Biological Activity
This isn't something we particularly have to know, but its just saying that the shape plays a role in how certain things function. Like a protein would work better folded in a certain way vs if it was just a chain of amino acids. The shape can either improve its ability or diminish it.
- Tue Nov 13, 2018 5:26 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Homework Problem: SOCl2 bond angles
- Replies: 1
- Views: 385
Re: Homework Problem: SOCl2 bond angles
It has to do with the fact that they are both bonds. (vs it being lone pairs) because all ends are bonds and there are no lone pairs. the repelling is equally distributed.
- Tue Nov 13, 2018 5:16 pm
- Forum: Octet Exceptions
- Topic: List of octect exceptions
- Replies: 6
- Views: 648
Re: List of octect exceptions
For these exceptions are we able to draw a Lewis structure for them? (if any)
- Tue Nov 13, 2018 5:11 pm
- Forum: Resonance Structures
- Topic: Resonance Structures
- Replies: 6
- Views: 820
Resonance Structures
Can someone please give a formal definition to what resonance structures are? and why we use them?
- Tue Nov 13, 2018 5:09 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Stable Vs. Formal
- Replies: 4
- Views: 1050
Stable Vs. Formal
Is there a difference between the stable charge and the formal charge? if they are explain please and thank you.
- Tue Nov 13, 2018 4:57 pm
- Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
- Topic: Shape and Boiling Point
- Replies: 12
- Views: 3013
Re: Shape and Boiling Point
Does the distance between the bonds effect the boiling point? Would this cause the bond to be stronger or weaker? This distance between the bonds would have an effect on the boiling point or how easily the bonds are broken. This is how I think about it to determine whether it is a stronger bond or ...
- Tue Nov 13, 2018 4:55 pm
- Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
- Topic: Shape and Boiling Point
- Replies: 12
- Views: 3013
Re: Shape and Boiling Point
I think most of what he was referring to with boiling point and shape, was how if there is more surface area touching than the rod for example would be a harder bond to break, versus when you look at to circles only has a little piece touching there for it is an easier bond to break.
- Sat Nov 10, 2018 6:38 pm
- Forum: Ionic & Covalent Bonds
- Topic: Dissociation Energy
- Replies: 3
- Views: 372
Re: Dissociation Energy
Okay, if the negative is releasing or absorbing energy what does the positive indicate?
- Sat Nov 10, 2018 6:36 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Shielding [ENDORSED]
- Replies: 15
- Views: 2034
Re: Shielding [ENDORSED]
WHAT DOES THIS EVEN MEAN????? I don't even remember this being talked about.
- Sat Nov 10, 2018 6:32 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Degeneracy
- Replies: 8
- Views: 1339
Re: Degeneracy
To find how many degenerate orbitals there are using Ml.
let's say L is 1.
so Ml is =-1,0,1
by that we count how many there are in Ml (3). so we have three degenerate orbitals for this atom.
let's say L is 1.
so Ml is =-1,0,1
by that we count how many there are in Ml (3). so we have three degenerate orbitals for this atom.
- Sat Nov 10, 2018 6:30 pm
- Forum: Trends in The Periodic Table
- Topic: Bond Lenghts
- Replies: 7
- Views: 884
Re: Bond Lenghts
Lavelle explained a bit more on the lengths and strengths of the bonds in class on Wednesday. I would ask him if you still have any doubts.
- Sat Nov 10, 2018 6:28 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: E- configuration
- Replies: 3
- Views: 411
E- configuration
Hi, can someone write like exactly what order we are suppose to write the configuration? because i keep getting mixed answers on whether s or d goes first. thanks
- Sat Nov 10, 2018 6:27 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg equation
- Replies: 3
- Views: 824
Re: Rydberg equation
wait, how does a negative indicate a higher state? is it because electrons are negative and as you have more it becomes more negative?
- Sat Nov 10, 2018 6:25 pm
- Forum: *Shrodinger Equation
- Topic: Shrodinger Equation
- Replies: 4
- Views: 783
Re: Shrodinger Equation
So if this is the case, did this have to do with the question on Test 2 about the probability of finding an electron in the center of an atom?
- Fri Oct 12, 2018 1:37 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Finding the volume of stock solution to dilute
- Replies: 13
- Views: 1246
Re: Finding the volume of stock solution to dilute
The standard one for this equation is Liters, but if asked otherwise, you should probably use liters for your volume.
- Fri Oct 12, 2018 1:36 pm
- Forum: Limiting Reactant Calculations
- Topic: How to determine the limiting reactant???? [ENDORSED]
- Replies: 8
- Views: 10813
Re: How to determine the limiting reactant???? [ENDORSED]
How I understood this was once you fin the amount in grams, the one with the bigger amount of moles that is need for the reaction is the limiting reactant. this is because you need more of this reactant to complete the equation. M9 in the textbook wasn't too much if you wanted a better idea with sma...
- Fri Oct 12, 2018 1:28 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: E23 part b
- Replies: 4
- Views: 756
Re: E23 part b
I also got confused here.
But as in the beginning it says you are looking the amount of moles and even though it says molecules you're looking for the amount of moles in that molecule they presented.
But as in the beginning it says you are looking the amount of moles and even though it says molecules you're looking for the amount of moles in that molecule they presented.
- Sun Oct 07, 2018 5:19 pm
- Forum: Limiting Reactant Calculations
- Topic: Module 3 Question
- Replies: 3
- Views: 209
Re: Module 3 Question
Lavelle said the only way this could happen was in a nuclear reaction, but that we didn't have to worry about this until later.
so it can only be the same as or less than.
so it can only be the same as or less than.
- Sun Oct 07, 2018 5:01 pm
- Forum: SI Units, Unit Conversions
- Topic: Avogadro's Number [ENDORSED]
- Replies: 11
- Views: 1335
Re: Avogadro's Number [ENDORSED]
would you use the inverse if you're going in the opposite direction?
can someone clarify what would it be for :
- atoms to moles
- moles to atoms
thank you
can someone clarify what would it be for :
- atoms to moles
- moles to atoms
thank you
- Sun Oct 07, 2018 4:42 pm
- Forum: SI Units, Unit Conversions
- Topic: Fundamental E3
- Replies: 6
- Views: 563
Re: Fundamental E3
you would multiply the actually quantity of gallium you have (9), by the molar mass given 70g/mol. this total will be equal to the molar mass of astatine 210g/mol times the amount of astatine you have. The amount of astatine is unknown so put a variable and then solve for it.
9 x 70 = 210 x A
9 x 70 = 210 x A