The order is supposed to be
solid | aqueous || aqueous | solid
Search found 60 matches
- Fri Mar 15, 2019 6:34 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: cell diagram order, review session
- Replies: 2
- Views: 330
- Fri Mar 15, 2019 6:32 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Limiting Reagents
- Replies: 5
- Views: 654
Re: Limiting Reagents
If the chemical reaction depends on the yield of product, or you are given a certain amount of reactants to work with.
- Fri Mar 15, 2019 6:31 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: q=mCdeltaT
- Replies: 15
- Views: 8196
Re: q=mCdeltaT
It depends on what units are given in the problem. Use whichever is simplest.
- Fri Mar 15, 2019 6:30 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: using q=n(deltaH) vs q=mc(deltaT)
- Replies: 4
- Views: 14298
Re: using q=n(deltaH) vs q=mc(deltaT)
Use q=mcdeltat when dealing with the slope part of the phase change diagram. Use the other equation when the line is flat (no phase change occurring).
- Fri Mar 15, 2019 6:28 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: 9.63 Positive delta G
- Replies: 3
- Views: 650
Re: 9.63 Positive delta G
A positive delta G indicates that the reaction is nonspontaneous, or nonfavorable.
- Fri Mar 15, 2019 6:27 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Delta G spontaneity
- Replies: 7
- Views: 1238
Re: Delta G spontaneity
When you plug in the temperature and other variables, as long as delta G is negative, then the reaction is spontaneous.
- Fri Mar 15, 2019 6:26 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs free energy units
- Replies: 3
- Views: 1783
Re: Gibbs free energy units
The unit is kJ/mol
- Fri Mar 15, 2019 6:24 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs Free Energy and Entropy
- Replies: 6
- Views: 962
Re: Gibbs Free Energy and Entropy
The other variable in the ghost equation also factor in whether or not delta S is positive or negative.
- Fri Mar 15, 2019 6:23 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Spontaneous Reaction
- Replies: 5
- Views: 783
Re: Spontaneous Reaction
I thought of it as a spontaneous reaction because when the temperature is -10 degrees C, then snow precipitating is spontaneous, thus delta G is negative.
- Sun Feb 24, 2019 10:50 pm
- Forum: Balancing Redox Reactions
- Topic: Skeleton Equations
- Replies: 3
- Views: 326
Re: Skeleton Equations
skeleton equations don't involve e- or waters.
- Sun Feb 24, 2019 10:49 pm
- Forum: Balancing Redox Reactions
- Topic: Mnemonic for Redox
- Replies: 5
- Views: 1012
Re: Mnemonic for Redox
OIL RIG
oxidation is loss (of e-)
reduction is gain (of e-)
oxidation is loss (of e-)
reduction is gain (of e-)
- Sun Feb 24, 2019 10:48 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: What is E?
- Replies: 4
- Views: 445
Re: What is E?
The nought symbol indicates standard conditions.
- Sun Feb 24, 2019 6:54 pm
- Forum: Balancing Redox Reactions
- Topic: Test 2 Material
- Replies: 13
- Views: 1391
Re: Test 2 Material
yes, you will have to know how to do that.
- Sun Feb 24, 2019 6:53 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Relation to Enthalpy and Entropy
- Replies: 4
- Views: 1582
Re: Relation to Enthalpy and Entropy
By using the gibbs free energy equation, you see the relationship between each component.
- Sun Feb 24, 2019 6:49 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: gibbs free energy
- Replies: 5
- Views: 611
Re: gibbs free energy
Gibbs free energy will tell you if a reaction is spontaneous or not.
- Sun Feb 10, 2019 9:47 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Open vs Closed System
- Replies: 13
- Views: 4594
Re: Open vs Closed System
Closed systems have a barrier that prevents matter from escaping. Open systems have no form of barrier that prevents anything from being transferred to the surrounding.
- Sun Feb 10, 2019 9:42 pm
- Forum: Phase Changes & Related Calculations
- Topic: Celsius and Kelvin
- Replies: 6
- Views: 645
Re: Celsius and Kelvin
You don't need to convert it when you're only using the difference in the temperatures in your equation because the differences will be the same. You need to convert when you're using a specific temperature (not the change) and when you are trying to find a ratio between initial and final temperatur...
- Thu Jan 31, 2019 6:49 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Enthalpy Symbol
- Replies: 5
- Views: 3754
Re: Enthalpy Symbol
The naught symbol indicates that the conditions are standard.
- Thu Jan 31, 2019 6:47 pm
- Forum: Phase Changes & Related Calculations
- Topic: What Does U and q stand for?
- Replies: 9
- Views: 2370
Re: What Does U and q stand for?
delta U is internal energy and q is the heat.
- Thu Jan 31, 2019 6:46 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: closed vs isolated
- Replies: 14
- Views: 1087
Re: closed vs isolated
Energy can be exchanged with the surroundings. Nothing can be exchanged in an isolated system.
- Sat Jan 26, 2019 8:33 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: method 1
- Replies: 4
- Views: 435
Re: method 1
Yes, one of the points of adding the equations together is to cancel out compounds that are not needed.
- Sat Jan 26, 2019 8:32 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Hess's Law
- Replies: 5
- Views: 461
Re: Hess's Law
Yes, make sure that all states of matter can cancel out and then manipulate each equation (multiplying or flipping) so that you get the final equation. Add together the enthalpies to find the enthalpy of the reaction.
- Sat Jan 26, 2019 8:29 pm
- Forum: Ideal Gases
- Topic: OH and H3O
- Replies: 10
- Views: 1376
Re: OH and H3O
You can calculate pH and pOH from [H30+] and [OH-] respectively by taking the negative log of the concentrations. This will indicate if the chemical compound is an acid or base.
- Mon Jan 21, 2019 10:57 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Percent Protonation
- Replies: 6
- Views: 545
Re: Percent Protonation
It is calculated by dividing the concentration of the conjugate acid by the concentration of the initial base and multiplying that by 100.
- Mon Jan 21, 2019 10:53 pm
- Forum: Ideal Gases
- Topic: ICE table
- Replies: 11
- Views: 1330
Re: ICE table
It can be used for both!
- Mon Jan 21, 2019 10:52 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: how to determine if something is an acid or base
- Replies: 4
- Views: 391
Re: how to determine if something is an acid or base
There is a list of common acids/bases that you could take a look at which could help you determine if a compound is an acid or base. You can also look at the pH if it is given, and that is a clear indicator of which one it is.
- Thu Jan 17, 2019 1:17 pm
- Forum: Ideal Gases
- Topic: Water
- Replies: 13
- Views: 1108
Re: Water
Water can be a solid liquid or gas, but not aqueous.
- Thu Jan 17, 2019 1:15 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Q vs K [ENDORSED]
- Replies: 4
- Views: 540
Re: Q vs K [ENDORSED]
Q can be calculated at any given point of the reaction. K is calculated when the system is in equilibrium.
- Thu Jan 17, 2019 1:03 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE Tables [ENDORSED]
- Replies: 11
- Views: 2442
Re: ICE Tables [ENDORSED]
You will be given this information from the question.
- Sat Dec 08, 2018 5:20 pm
- Forum: Administrative Questions and Class Announcements
- Topic: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
- Replies: 118
- Views: 21552
Re: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
Thank you for the churro review! I also really liked garlic bread(:
- Sun Dec 02, 2018 11:36 pm
- Forum: Naming
- Topic: Roman Numeral
- Replies: 5
- Views: 615
Re: Roman Numeral
The roman numerals correlate with the transition metal's oxidation number. Ag, Fe, Cu, and Pb are some examples of elements that need a roman numeral when naming them.
Re: Naming
OH2 and H2O are used depending on which element is doing the bonding. Two elements that bind together will be written right next to each other.
- Sun Dec 02, 2018 11:15 pm
- Forum: Naming
- Topic: Naming Question
- Replies: 5
- Views: 761
Re: Naming Question
OH2 has a charge of zero. Cl has a charge of 1-, so that means Fe has a charge of 2+ because the overall charge of the compound is 1+.
- Sun Nov 25, 2018 10:12 pm
- Forum: Properties of Light
- Topic: Speed of light
- Replies: 13
- Views: 3900
Re: Speed of light
Use the given constants until the end of the problem and then round to your significant figures!
- Sun Nov 25, 2018 10:09 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Naming
- Replies: 5
- Views: 502
Re: Naming
Yes, the molecular geometry and electron arrangements would be the same if there are no lone pairs.
- Sun Nov 25, 2018 10:08 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Naming the Shape
- Replies: 16
- Views: 1279
Re: Naming the Shape
There are charts that are organised in a specific way that can help with memorizing. You can google molecular shapes and be able to find a chart!
- Sun Nov 25, 2018 10:03 pm
- Forum: Electronegativity
- Topic: Electronegativity
- Replies: 4
- Views: 1085
Re: Electronegativity
The periodic table that is provided is always the same, so you can refer to the past periodic tables that have been provided.
- Sun Nov 25, 2018 10:00 pm
- Forum: Sigma & Pi Bonds
- Topic: Double Bonds
- Replies: 9
- Views: 1045
Re: Double Bonds
Double bonds have a sigma and a pi bond!
- Sun Nov 25, 2018 9:59 pm
- Forum: Electronegativity
- Topic: Radius
- Replies: 13
- Views: 1614
Re: Radius
As electronegativity increases, the pull on the electrons is greater. This means that the electrons are closer to the nucleus, thus giving the molecule a smaller atomic radius.
- Sun Nov 18, 2018 8:21 pm
- Forum: Bond Lengths & Energies
- Topic: Strength of Bonds
- Replies: 9
- Views: 1083
Re: Strength of Bonds
The stronger the bond, the higher the melting/boiling point.
- Sun Nov 18, 2018 12:44 pm
- Forum: Bond Lengths & Energies
- Topic: Bond Length and Resonance
- Replies: 5
- Views: 1736
Re: Bond Length and Resonance
Bond lengths are the same. Resonance structures give different locations for the different types of bonds, but lengths of the bonds are the same.
- Sun Nov 18, 2018 12:42 pm
- Forum: Bond Lengths & Energies
- Topic: Bond Lengths
- Replies: 4
- Views: 548
Re: Bond Lengths
In nature, the bond lengths are going to be the same for double and triple and single bonds in a molecule.
- Mon Nov 12, 2018 12:17 am
- Forum: Bond Lengths & Energies
- Topic: Determine bond length
- Replies: 3
- Views: 470
Re: Determine bond length
You would need to know the different bond lengths to gauge how long a bond length would be in relation to the given length. In other words, you need to be given at least one bond length in order to give a relative bond length in relation to the given.
- Mon Nov 12, 2018 12:15 am
- Forum: Lewis Structures
- Topic: Formal Charge
- Replies: 14
- Views: 1318
Re: Formal Charge
To let the structure be as stable as possible, a charge of 0 is the most stable. The outer elements can have a charge as long as the charges are symmetrical for it to still be stable.
- Mon Nov 12, 2018 12:13 am
- Forum: Octet Exceptions
- Topic: Octet exceptions
- Replies: 8
- Views: 1237
Re: Octet exceptions
Elements that are past the 3rd period can have an expanded octet, but it depends on what the compound is to determine whether or not it needs to use an expanded octet.
- Fri Nov 02, 2018 4:46 pm
- Forum: Bond Lengths & Energies
- Topic: Test 3 bond length question
- Replies: 8
- Views: 1046
Re: Test 3 bond length question
Longer bonds mean that they are weaker.
- Fri Nov 02, 2018 4:45 pm
- Forum: Bond Lengths & Energies
- Topic: Bond Length
- Replies: 9
- Views: 1137
Re: Bond Length
Single bonds are longer than double bonds, and double bonds are longer than triple bonds. This is because of the strength of the bonds.
- Fri Nov 02, 2018 4:41 pm
- Forum: Bond Lengths & Energies
- Topic: Lengths of Bonds
- Replies: 9
- Views: 663
Re: Lengths of Bonds
Double bonds are shorter than single bonds because double bonds are stronger and more attracted to the protons in the nucleus. Single bonds are as strong, therefore they are not going to be as attracted to the nucleus.
- Sun Oct 28, 2018 9:35 pm
- Forum: *Shrodinger Equation
- Topic: Application of Equation on test
- Replies: 5
- Views: 862
Re: Application of Equation on test
We don’t need to know how to use it to calculate anything.
- Sun Oct 28, 2018 9:34 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Delta X relationship with Delta P
- Replies: 3
- Views: 2568
Re: Delta X relationship with Delta P
If delta x increases, then delta p will decrease.
- Sun Oct 28, 2018 9:14 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Degeneracy
- Replies: 5
- Views: 488
Re: Degeneracy
To add on, if the orbital you’re talking about isn’t the p orbital, how do you know the degeneracy?
- Mon Oct 22, 2018 12:09 am
- Forum: Trends in The Periodic Table
- Topic: Largest in Atomic Radii?
- Replies: 5
- Views: 608
Re: Largest in Atomic Radii?
More protons means that the pull on electrons surrounding the atom is greater. This pull makes the atomic radius smaller.
- Sun Oct 21, 2018 11:28 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Symmetric vs. Non symmetric orbitals
- Replies: 4
- Views: 1436
Re: Symmetric vs. Non symmetric orbitals
The symmetry helps us understand how the structures are shaped.
- Sun Oct 21, 2018 10:58 pm
- Forum: Photoelectric Effect
- Topic: Work Function
- Replies: 16
- Views: 849
Re: Work Function
Josephine Lu 1L wrote:Is the unit of work function Joules, or Joules per photon?
The unit for work is joules! And joules = kg.m^2.s^-2
- Mon Oct 15, 2018 1:48 am
- Forum: Limiting Reactant Calculations
- Topic: Percent Yield [ENDORSED]
- Replies: 13
- Views: 2904
Re: Percent Yield [ENDORSED]
More often than not, the actual yield will be less than the theoretical yield because in reactions, there is always room to make error and chemical products and reactants could "escape" the experiment. The actual yield is the yield you get from conducting the experiment in real life, and t...
- Mon Oct 15, 2018 1:46 am
- Forum: Empirical & Molecular Formulas
- Topic: Is it possible for the Empirical and Molecular formula to be the same? [ENDORSED]
- Replies: 8
- Views: 1285
Re: Is it possible for the Empirical and Molecular formula to be the same? [ENDORSED]
It is completely possible! If the given molecular weight is calculated to be the same as the empirical formula's molecular weight, then it is the same!
- Mon Oct 15, 2018 1:45 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: diatomic elements
- Replies: 12
- Views: 9942
Re: diatomic elements
Diatomic elements only need to exist in pairs of atoms when they are standing alone. For instance, in OH-, you wouldn't need two hydrogen atoms because the hydrogen is not free standing. However, if you have hydrogen gas, you would need H2 because it is not attached to a different element.
- Sun Oct 07, 2018 3:10 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Rounding molar mass
- Replies: 4
- Views: 325
Re: Rounding molar mass
I always use three decimals for the molar mass from the given periodic table masses. At the very end of the problem is when I round any number that I use in my calculations. This ensures that I don't miss anything or have any miscalculations.
- Sun Oct 07, 2018 3:08 pm
- Forum: Empirical & Molecular Formulas
- Topic: Molecular Formula
- Replies: 12
- Views: 603
Re: Molecular Formula
If atoms are linked together, they form one compound. Count up each type of atom to form the compounds used in the equation and use them to make a balanced chemical equation.
- Sun Oct 07, 2018 3:06 pm
- Forum: Significant Figures
- Topic: Rounding numbers ending in 5
- Replies: 9
- Views: 898
Re: Rounding numbers ending in 5
I usually use the most exact number (from the calculator) when dealing with the problem, and at the very end, I round to however many significant figures there are given from the problem.