Search found 101 matches
- Sat Mar 14, 2020 5:57 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: HCl as anode and cathode in cell diagram
- Replies: 3
- Views: 245
Re: HCl as anode and cathode in cell diagram
I think this means that is a concentration cell. In this case you would use the nernst equation, but e standard is 0.
- Sat Mar 14, 2020 5:54 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Arrhenius equation
- Replies: 2
- Views: 236
Re: Arrhenius equation
Yeah im pretty sure youd be given both K values or enough information would be given to calculate one
- Sat Mar 14, 2020 5:46 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: h20 in our rate law
- Replies: 3
- Views: 298
Re: h20 in our rate law
if the water is aqueous, i think it would be included
- Sat Mar 14, 2020 5:45 pm
- Forum: Experimental Details
- Topic: Textbook 7A.17
- Replies: 2
- Views: 368
Re: Textbook 7A.17
have you tried log(5.839) / log(2.5)?
- Sat Mar 14, 2020 5:42 pm
- Forum: Ideal Gases
- Topic: Weak vs Strong Acids and Bases
- Replies: 3
- Views: 348
Re: Weak vs Strong Acids and Bases
when solving for strong acids/bases, the concentration of the acid is always equal to the concentration of hydroxide or hydronium because they dissociate completely. When solving for weak strong acids or bases, you must always put them in water and use an ice table to calculate the concentration of ...
- Sun Mar 08, 2020 10:20 pm
- Forum: General Rate Laws
- Topic: 7B3a
- Replies: 3
- Views: 309
Re: 7B3a
that is equal to ln(2) which is part of the formula to find the half life of a reaction
- Sun Mar 08, 2020 10:16 pm
- Forum: General Rate Laws
- Topic: 7A.9
- Replies: 5
- Views: 348
Re: 7A.9
calculate the mols of N2O5 present, and multiply it by the reaction rate.
- Sun Mar 08, 2020 10:12 pm
- Forum: General Rate Laws
- Topic: Difference b/w General Rate Laws/Elementary
- Replies: 2
- Views: 267
Re: Difference b/w General Rate Laws/Elementary
I'm pretty sure we can associate something that is first order with being unimolecular!
- Sun Mar 08, 2020 10:08 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Molecularity and rate laws
- Replies: 5
- Views: 409
Re: Molecularity and rate laws
I think that if something is unimolecular, the order of the reaction would be one. similarly, if something is bimolecular, the order of the reaction would be two.
- Sun Mar 08, 2020 10:03 pm
- Forum: Second Order Reactions
- Topic: How to Derive 2nd Order Integral Rate Law
- Replies: 4
- Views: 285
Re: How to Derive 2nd Order Integral Rate Law
Integrate similarly to first order reaction, but now integrate -d[A]/[A]^2 which turns out to be 1/[A].
- Mon Mar 02, 2020 12:26 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: concentration cell
- Replies: 3
- Views: 245
Re: concentration cell
Yeah! A concentration cell has the same ion on both sides, but different concentrations. I'm not sure how it can be compared to a galvanic cell though, sorry.
- Mon Mar 02, 2020 12:21 am
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Overall reaction order
- Replies: 3
- Views: 290
Re: Overall reaction order
i think its the orders of all the reactants added together!
- Mon Mar 02, 2020 12:18 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: 6O.3
- Replies: 2
- Views: 248
Re: 6O.3
I think it asking whether the water has a larger reduction potential or the metal ion. Hope this helps :D
- Mon Mar 02, 2020 12:14 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 6o.3
- Replies: 1
- Views: 137
6o.3
I understand how to look at the table to find out whether the reduction potentials are a larger positive number for the metal ion or water, but I am a little confused on where to go after that. If the cathode has a really large negative reduction potential(which we don't want), doesn't that mean tha...
- Sun Mar 01, 2020 11:35 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Difference Between Galvanic and Voltaic Cells
- Replies: 3
- Views: 270
Re: Difference Between Galvanic and Voltaic Cells
They're the same thing, I think!
- Sun Feb 23, 2020 11:37 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Salt Bridges
- Replies: 3
- Views: 273
Salt Bridges
What is a salt bridge used for? I’m kinda confused about their role in galvanic cells
- Sun Feb 23, 2020 11:29 pm
- Forum: Van't Hoff Equation
- Topic: Van’t Hoff Equation
- Replies: 11
- Views: 916
Re: Van’t Hoff Equation
The Van't Hoff Equation can be used to calculate the k at a different temperature if change in enthalpy is known and is constant.
- Sun Feb 23, 2020 11:25 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Platinum
- Replies: 2
- Views: 237
Re: Platinum
We use platinum because we need solid to channel and donate the electrons. Platinum is a good electric conductor.
- Sun Feb 23, 2020 11:24 pm
- Forum: Balancing Redox Reactions
- Topic: acidic solutions
- Replies: 3
- Views: 296
Re: acidic solutions
If you need more H you would add hydronium (H+) to the solution.
- Sun Feb 23, 2020 11:23 pm
- Forum: Balancing Redox Reactions
- Topic: basic solution
- Replies: 3
- Views: 249
Re: basic solution
You balance the oxygens by using water, and balance the charges by adding hydroxide.
- Sun Feb 23, 2020 11:16 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Difference in phases
- Replies: 5
- Views: 305
Re: Difference in phases
The single line is for difference in phases, whereas the commas represent them in the same solution.
- Mon Feb 17, 2020 3:04 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Open Systems
- Replies: 15
- Views: 848
Re: Open Systems
I think a question will explicitly tell you if the system is open
- Mon Feb 17, 2020 3:03 pm
- Forum: Balancing Redox Reactions
- Topic: 6k3 part d
- Replies: 4
- Views: 186
Re: 6k3 part d
I think its because cl2 is used as both the oxidizing and reducing agent
- Mon Feb 17, 2020 1:18 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Open Systems
- Replies: 15
- Views: 848
Re: Open Systems
Since open systems are permeable to energy and matter, im pretty sure all thermodynamic equations can be applied
- Mon Feb 17, 2020 1:12 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Reversible and Irreversible
- Replies: 5
- Views: 448
Re: Reversible and Irreversible
I think so, because entropy is a state function so the pathway does not matter
- Mon Feb 17, 2020 1:11 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Free Energy and Work
- Replies: 5
- Views: 397
Re: Free Energy and Work
Im pretty sure that if there is a free expansion, work equals zero because the system does not have to counteract a compressive force
- Sun Feb 09, 2020 6:34 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: difference between molar entropies?
- Replies: 6
- Views: 334
Re: difference between molar entropies?
lead has a significantly higher amount of particles( protons, neutrons, and electrons) than carbon which means it has a higher degeneracy, and thus a higher entropy.
- Sun Feb 09, 2020 6:25 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: Boltzmann Entropy Equation Clarificaiton
- Replies: 3
- Views: 62
Re: Boltzmann Entropy Equation Clarificaiton
Yes, i think the equation shows the proportional relationship between possible microstates and entropy. I would use the equation of the question mentioned a quantity of particles and possible energy states
- Sun Feb 09, 2020 5:55 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Pizza Rolls - State Functions
- Replies: 5
- Views: 277
Re: Pizza Rolls - State Functions
I think it was when PD TV HUGS
- Sun Feb 09, 2020 5:50 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Example 4D.1
- Replies: 1
- Views: 111
Re: Example 4D.1
I think it's because we're looking for delta H per mole of C6H6. In that case, you take the delta H of the reaction and divide it by the coefficient of the reactant or product.
- Sun Feb 09, 2020 5:46 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: 4I.5
- Replies: 4
- Views: 137
Re: 4I.5
I think we assume this because it says the reaction takes place in a single vessel, so there wouldnt be any changes in volume
- Sun Feb 02, 2020 7:27 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic bonds in solutions
- Replies: 9
- Views: 789
Re: Ionic bonds in solutions
I think ionic bonds are breaking, but I think the dissolving of salts is a physical change
- Sun Feb 02, 2020 7:24 pm
- Forum: Calculating Work of Expansion
- Topic: Work Formula
- Replies: 2
- Views: 44
Re: Work Formula
I think the integral just shows how the work formula is derived, so I dont think we would need to know it for the midterm.
- Sun Feb 02, 2020 5:09 pm
- Forum: Calculating Work of Expansion
- Topic: 4A.13
- Replies: 2
- Views: 122
Re: 4A.13
Since C= q/delta T, you can divide 3.50 kJ by 7.32 K and get C=0.478 kJ/K. From there you can multiply that number with the change of temperature(2.47 kJ) of the calorimeter to find q of the calorimeter. The q of the reaction is the negative value of the q of the calorimeter
- Sun Feb 02, 2020 2:02 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Microstates
- Replies: 5
- Views: 204
Re: Microstates
I think a microstate is the way in we can arrange the energy of a system and as the amount of atoms in the system increases, the amount of possible microstates also increases. Knowing this value helps calculate entropy.
- Sun Feb 02, 2020 1:59 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: degeneracy
- Replies: 3
- Views: 127
Re: degeneracy
degeneracy is the number of ways of achieving a given state. The equation to calculate this number is W= 2^n, which is why if there are 3 atoms, there are 8 possible microstates.
- Sun Jan 26, 2020 8:51 pm
- Forum: Calculating Work of Expansion
- Topic: Work Units
- Replies: 3
- Views: 109
Re: Work Units
Joules i think
- Sun Jan 26, 2020 8:50 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bond Enthalpies
- Replies: 3
- Views: 130
Re: Bond Enthalpies
I they're found experimentally, so in a problem, they should usually be given
- Sun Jan 26, 2020 8:49 pm
- Forum: Phase Changes & Related Calculations
- Topic: enthalpy of phase changes
- Replies: 8
- Views: 230
Re: enthalpy of phase changes
I dont think so, because heat is always required during those phase changes
- Thu Jan 23, 2020 2:43 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Ka correlation to strength of an acid
- Replies: 30
- Views: 2152
Ka correlation to strength of an acid
what is the relationship between the Ka and how strong an acid is?
- Thu Jan 23, 2020 2:28 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: pKa to Kb
- Replies: 12
- Views: 602
pKa to Kb
im a little confused on how to convert pKa to Kb? I think theres multiple ways, but what's the easiest way to do it?
- Mon Jan 20, 2020 10:42 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 6E.3
- Replies: 1
- Views: 57
Re: 6E.3
I think since it's polyprotic, when the first H+ ion breaks off, it does so completely, which refers to the "very large Ka". When the second H+ ion breaks off, you use an ice table, but must recognize that there is already an initial concentration of hydronium from when the first H+ ion br...
- Mon Jan 20, 2020 10:37 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5% rule
- Replies: 3
- Views: 100
Re: 5% rule
Yes I believe it's the change in reactant concentration, so you would take into account coefficients.
- Mon Jan 20, 2020 10:32 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 6A.3a
- Replies: 1
- Views: 58
Re: 6A.3a
HI is a strong acid so it breaks apart completely, meaning that the concentration of the acid is the same as the concentration of the hydronium ions. From there, you can convert to pH, subtract the pH from 14 to find the pOH, and convert back into hydroxide concentration.
- Mon Jan 20, 2020 10:28 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 6D.7
- Replies: 3
- Views: 129
Re: 6D.7
Find the initial concentration of the weak acid or base in each of the following aqueous solutions: (a) a solution of HClO with pH 5 4.60; (b) a solution of hydrazine, NH2NH2, with pH 5 10.20. Your K expression should read ([H30+][CLO-])/[HCLO]. Since you are given pH, you can find [H30+] using 10^-...
- Mon Jan 20, 2020 10:13 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: 5J.1
- Replies: 2
- Views: 103
5J.1
5J.1 reads "Consider the equilibrium CO(g) + H2O(g) --> CO2(g) + H2(g). (a) If the partial pressure of CO2 is increased, what happens to the partial pressure of H2? (b) If the partial pressure of CO is decreased, what happens to the partial pressure of CO2? (c) If the concentration of CO is inc...
- Sun Jan 12, 2020 9:58 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Values of K and Meaning
- Replies: 3
- Views: 174
Re: Values of K and Meaning
k>1 does indicate that products are slightly more favored than reactants however I think k>10^3 guarantees favoritism.
- Sun Jan 12, 2020 9:54 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Concentration affecting equilibrium
- Replies: 5
- Views: 218
Re: Concentration affecting equilibrium
I think that decreasing the concentration of products will decrease the reaction quotient while increasing the concentration pf products will increase the reaction quotient
- Sun Jan 12, 2020 9:51 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Ice tables for partial pressures
- Replies: 4
- Views: 178
Re: Ice tables for partial pressures
Yes, both partial pressure and concentration can be used in ice tables
- Sun Jan 12, 2020 9:48 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: "quick" way?
- Replies: 4
- Views: 167
Re: "quick" way?
The quick way is just knowing that when pressure is increasing, then the reaction will go towards the direction with less moles and when the pressure is decreasing, the reaction will go towards the direction with more moles. The longer way is realizing that when pressure is changing, the actual volu...
- Sun Jan 12, 2020 9:42 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: What is this?
- Replies: 23
- Views: 1411
Re: What is this?
What exactly does le chatelier's principle apply to? Is it just concentration of reactants/products, temperature, and pressure/volume or are there more factors that can be applied?
- Sat Dec 07, 2019 6:05 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: dien
- Replies: 3
- Views: 278
Re: dien
dien is tridenate im pretty sure, and i think carbonate and nitrito might be ambidentate
- Sat Dec 07, 2019 6:02 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: polydentate naming
- Replies: 1
- Views: 151
Re: polydentate naming
I think those are good, but maybe also sulfato? I'm not really sure if sulfato is considered bidentate though
- Sat Dec 07, 2019 6:00 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Polydentate
- Replies: 1
- Views: 112
Re: Polydentate
I thought that carbonate was bidentate due to its 2 oxygens with -1 formal charge, but I have seen in a lot of places that it is monodentate bc it has 120 degree bond angles.
- Sat Dec 07, 2019 5:57 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Shape of Coordination Compounds
- Replies: 2
- Views: 196
Re: Shape of Coordination Compounds
I think polydentates do affect shape of coordination compounds because they offer more than one binding site. For example, since en has two binding sites, it will increase the coordination compound by 2
- Sat Dec 07, 2019 5:54 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Sulfato
- Replies: 1
- Views: 116
Sulfato
is sulfato bidentate since two oxygens have a -1 formal charge which can act as binding spots?
- Sun Dec 01, 2019 11:59 pm
- Forum: Lewis Acids & Bases
- Topic: Definition
- Replies: 7
- Views: 548
Re: Definition
A Lewis acid is an electron-pair acceptor and a Lewis base is an electron-pair donor.
- Sun Dec 01, 2019 11:57 pm
- Forum: Lewis Acids & Bases
- Topic: Long bonds vs Short bonds?
- Replies: 9
- Views: 887
Re: Long bonds vs Short bonds?
This is why acids with longer bonds are stronger, while acids with shorter bonds are acids. Strong acids with weak/long bonds can dissociate completely while weak acids with short/strong bonds cannot.
- Sun Dec 01, 2019 11:53 pm
- Forum: Lewis Acids & Bases
- Topic: Weak vs. Strong
- Replies: 8
- Views: 702
Re: Weak vs. Strong
An example of a strong acid is HI, which has long/weak bonds and can dissociate completely. An example of a weak acid is HF, which has short/strong bonds and does not dissociate completely.
- Sun Dec 01, 2019 11:49 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: 6D. 11
- Replies: 1
- Views: 178
Re: 6D. 11
For each molecule, look at what the products of dissociation are because they will indicate whether they are acids or bases. For example, NH4Br will dissociate into NH4+ + Br-. NH4+ is able to give up a proton so the solution will be acidic.
- Sun Dec 01, 2019 11:42 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Oxoacids
- Replies: 1
- Views: 118
Re: Oxoacids
An oxoacid contains oxygen, contains at least one other element, and has at least one hydrogen atom bonded to the oxygen.
The oxoacids more readily lose a H+ if the resulting anion can be stabilized by electron withdrawing atoms.
The oxoacids more readily lose a H+ if the resulting anion can be stabilized by electron withdrawing atoms.
- Mon Nov 25, 2019 11:31 am
- Forum: Hybridization
- Topic: Hybridization Formulas
- Replies: 2
- Views: 106
Re: Hybridization Formulas
You just subtract 1 from the amount of bonding regions!
- Mon Nov 25, 2019 11:30 am
- Forum: Hybridization
- Topic: Question 2F.15
- Replies: 2
- Views: 225
Re: Question 2F.15
viewtopic.php?p=2547&sid=0d36d6a0a83ae99de2b5592ede5e800f#p2547
Dr. Lavelle answered this question a couple years ago!
Dr. Lavelle answered this question a couple years ago!
- Mon Nov 25, 2019 11:26 am
- Forum: Naming
- Topic: Oxidation Numbers
- Replies: 2
- Views: 223
Re: Oxidation Numbers
The oxidation number of an atom is the charge that atom would have if the compound was composed of ions.
- Mon Nov 25, 2019 11:23 am
- Forum: Naming
- Topic: Roman numerals
- Replies: 6
- Views: 365
Re: Roman numerals
For example, Ni (I) would represent the +1 oxidation number of nickel while Ni (II) represents the +2 oxidation number
- Mon Nov 25, 2019 11:17 am
- Forum: Lewis Acids & Bases
- Topic: How to calculate pH and pOH
- Replies: 2
- Views: 293
Re: How to calculate pH and pOH
Then you can find the pOH by subtracting the pH you calculated from 14.
- Sun Nov 17, 2019 4:02 pm
- Forum: Dipole Moments
- Topic: Dipole moments in trigonal bipyramidal shaped molecules
- Replies: 4
- Views: 562
Re: Dipole moments in trigonal bipyramidal shaped molecules
Different atoms often have differences in electronegativity which causes them to be polar even if their geometry is symmetrical.
- Sun Nov 17, 2019 3:59 pm
- Forum: Dipole Moments
- Topic: 2E. 25a
- Replies: 2
- Views: 138
Re: 2E. 25a
Also, I think since the hydrogen atom is less electronegative than chlorine atom, there is a net dipole moment in the compound.
- Sun Nov 17, 2019 3:55 pm
- Forum: Dipole Moments
- Topic: Polar vs. Non-polar bonds
- Replies: 2
- Views: 183
Re: Polar vs. Non-polar bonds
You can also look at molecular geometry. Sometimes certain structures indicate polarity. For example since h2o has a bent structure, it is also a polar molecule.
- Sun Nov 17, 2019 3:50 pm
- Forum: Dipole Moments
- Topic: Polar and Non polar
- Replies: 2
- Views: 233
Re: Polar and Non polar
You can also use molecular geometry to find polarity. For example, lone pairs on oxygen in h2o cause there to be bent geometry, which thus indicates that the molecule is polar.
- Sun Nov 17, 2019 3:47 pm
- Forum: Dipole Moments
- Topic: 3F.3
- Replies: 2
- Views: 131
Re: 3F.3
I think that the hydrogen atom is less electronegative than the chlorine atom so, there is a net dipole moment in the compound. Also, the arrangement of the bonded pairs is asymmetric,
- Sun Nov 10, 2019 5:29 pm
- Forum: Octet Exceptions
- Topic: Reasoning for Octet Exception
- Replies: 19
- Views: 1161
Re: Reasoning for Octet Exception
Also, expanded octets can occur in all elements starting period 3 and below!
- Sun Nov 10, 2019 5:27 pm
- Forum: Electronegativity
- Topic: Ionization Energy vs. Electronegativity
- Replies: 9
- Views: 9634
Re: Ionization Energy vs. Electronegativity
Also, electronegativity refers to the ability of an atom in a molecule to attract shared electrons. Ionization energy does not refer to molecules, only unbonded atoms.
- Sun Nov 10, 2019 5:23 pm
- Forum: Electronegativity
- Topic: Differences in Electronegativity
- Replies: 5
- Views: 364
Re: Differences in Electronegativity
We probably need to the know the general trend of electronegativity, which is proportional to ionization energy
- Sun Nov 10, 2019 5:18 pm
- Forum: Bond Lengths & Energies
- Topic: Bond Shape
- Replies: 3
- Views: 287
Re: Bond Shape
Since oxygen has the second highest electronegativity, it attracts electrons more strongly than hydrogen, thus causing an unequal sharing of electrons between the two atoms
- Sun Nov 10, 2019 5:13 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge Cancellation
- Replies: 3
- Views: 555
Re: Formal Charge Cancellation
Formal charge should be considered after the octet rule is observed in most cases!
- Sun Nov 03, 2019 12:27 pm
- Forum: Octet Exceptions
- Topic: Boron
- Replies: 2
- Views: 105
Re: Boron
Boron has too few of electrons to provide an octet for every atom.
- Sun Nov 03, 2019 12:17 pm
- Forum: Bond Lengths & Energies
- Topic: Strength of Bonds
- Replies: 16
- Views: 628
Re: Strength of Bonds
longer bonds are easier to break, so they are weaker. Shorter bonds are harder to break, so they are stronger.
- Sun Nov 03, 2019 12:12 pm
- Forum: Bond Lengths & Energies
- Topic: Strength related to reactivity
- Replies: 2
- Views: 186
Re: Strength related to reactivity
Since longer bonds are weaker and easier to break, they are more likely to be involved in a reaction. Stronger bonds are shorter, harder to break, and less reactive.
- Sun Nov 03, 2019 12:08 pm
- Forum: Lewis Structures
- Topic: Bonds
- Replies: 4
- Views: 137
Re: Bonds
Also, when you're deciding whether to use single, double, or triple bonds, make sure that the elements in the first or second period are observing the octet rule!
- Sun Nov 03, 2019 12:05 pm
- Forum: Lewis Structures
- Topic: Formal charges on structures
- Replies: 2
- Views: 1571
Re: Formal charges on structures
Yes, the best structures have elements with 0 formal charge. If not, the most electronegative element should carry the negative formal charge.
- Sun Oct 27, 2019 3:22 pm
- Forum: Trends in The Periodic Table
- Topic: Ionization and Electron Affinity
- Replies: 5
- Views: 312
Re: Ionization and Electron Affinity
I'm pretty sure both the ionization energy and the electron affinity of an atom decrease as you go down a Group and increase as you go across a period. But there are some exceptions to these patterns.
- Sun Oct 27, 2019 3:12 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Noble gas electron configurations
- Replies: 3
- Views: 177
Re: Noble gas electron configurations
I'm pretty sure the electron configuration of neon is 1s22s2p6, so I think there are actually two electrons in the 1S sub-shell.
- Sun Oct 27, 2019 3:08 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: many electron atoms
- Replies: 2
- Views: 100
Re: many electron atoms
Does this also include electron affinity and IE?
- Sun Oct 27, 2019 3:05 pm
- Forum: Trends in The Periodic Table
- Topic: 1F.3
- Replies: 3
- Views: 261
1F.3
"Place the following ions in order of increasing ionic radius: S^2-, Cl^-, P^3-." Since all of these ions have the same amount of electrons, are we supposed to take into account core charge?
- Sun Oct 27, 2019 3:01 pm
- Forum: Trends in The Periodic Table
- Topic: Exceptions in the trends
- Replies: 4
- Views: 284
Re: Exceptions in the trends
Another example is that nitrogen's electron affinity is lower than carbon's and that Neon's is not only lower than fluorine's, but is actually lower than lithium's.These exceptions are also due to electron configurations!
- Sun Oct 20, 2019 5:33 pm
- Forum: *Shrodinger Equation
- Topic: Shrodinger Equation
- Replies: 3
- Views: 160
Re: Shrodinger Equation
The Schrodinger equation is used to find the allowed energy levels of quantum mechanical systems
- Sun Oct 20, 2019 5:31 pm
- Forum: Photoelectric Effect
- Topic: 1B.15
- Replies: 2
- Views: 143
1B.15
"The g-ray photons emitted by the nuclear decay of a technetium-99 atom used in radiopharmaceuticals have an energy of 140.511 keV. Calculate the wavelength of these g-rays" What is the unit keV?
- Sun Oct 20, 2019 5:29 pm
- Forum: Einstein Equation
- Topic: When do we use the Einstein Equation?
- Replies: 14
- Views: 761
Re: When do we use the Einstein Equation?
Im pretty sure it's used a lot because you can also isolate frequency in λv=C and subsitute it back into E=hv to find wavelength.
- Sun Oct 20, 2019 5:10 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Series
- Replies: 3
- Views: 159
Re: Series
The principal quantum number for the lower energy level involved is the same for each absorption line in a series. For example, Paschen series are the series of lines in the spectrum of the hydrogen atom which corresponds to transitions between the state with principal quantum number n = 3 and succe...
- Sun Oct 20, 2019 5:00 pm
- Forum: DeBroglie Equation
- Topic: 1B.21
- Replies: 3
- Views: 230
1B.21
1B.21 reads "A baseball must weigh between 5.00 and 5.25 ounces (1 ounce 5 28.3 g). What is the wavelength of a 5.15-ounce baseball thrown at 92 mph?" I understand the basic premise of the question, but I'm kind of confused about the conversations? Can someone explain the initial steps
- Sun Oct 13, 2019 10:42 am
- Forum: Photoelectric Effect
- Topic: 1B.9
- Replies: 2
- Views: 58
1B.9
"A lamp rated at 32 W (1 W 5 1 J?s21) emits violet light of wavelength 420 nm. How many photons of violet light can the lamp generate in 2.0 s? How many moles of photons are emitted in that time interval?" Can someone explain the initial step to figure this question out?
- Sun Oct 13, 2019 10:37 am
- Forum: Photoelectric Effect
- Topic: Proportional sign
- Replies: 4
- Views: 152
Re: Proportional sign
I'm not sure if this is what you mean, but the symbol ∝ is used for variables that are directly proportional to each other!
- Sun Oct 13, 2019 10:26 am
- Forum: Properties of Electrons
- Topic: Constructive vs Destructive Inference
- Replies: 4
- Views: 418
Re: Constructive vs Destructive Inference
Constructive interference happens when two waves meet so that their crests line up together, which results in a wave with a higher amplitude. In destructive interference, the crest of one wave meets the trough of another, resulting in a lower total amplitude. The Khan academy video about this is rea...
- Sun Oct 13, 2019 10:22 am
- Forum: Properties of Light
- Topic: 1A.3
- Replies: 3
- Views: 179
1A.3
For this question, I was able to use process of elimination, but I'm still pretty confused on the relationship between the frequency of electromagnetic radiation and the slope of the electric field. Does anyone know why they're related?
- Sun Oct 13, 2019 10:14 am
- Forum: Properties of Light
- Topic: 1A.11
- Replies: 2
- Views: 119
1A.11
Question 1A.11 asks: In the spectrum of atomic hydrogen, several lines are generally classified together as belonging to a series. What is common to the lines within a series that makes grouping them together logical? Does anyone know how to approach this question? I'm a little confused on the conce...
- Thu Oct 03, 2019 1:24 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Avogadro's Number?
- Replies: 16
- Views: 911
Re: Avogadro's Number?
Avogadro's number should be used if a problem asks for formula units, atoms, or molecules. To convert something to molecules or formula units, multiple moles by Avogadro's number. An example of this would be problem E.9 parts a and b.
- Thu Oct 03, 2019 1:19 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: F.13 homework problem
- Replies: 4
- Views: 279
Re: F.13 homework problem
Since phosphorus and chlorine are covalently bonded together, they make a covalent compound. Simple covalent compounds are generally named by using prefixes to indicate how many atoms of each element are shown in the formula. Also, the ending of the last (most negative) element is changed to -ide. T...
- Thu Oct 03, 2019 1:00 pm
- Forum: Empirical & Molecular Formulas
- Topic: Test Materials
- Replies: 13
- Views: 710
Re: Test Materials
Avogadro's number was given to me on formula sheets in my high school chemistry class, so I think it could be on there, but it might be safer to just memorize it.
- Thu Oct 03, 2019 12:56 pm
- Forum: Significant Figures
- Topic: significant figures
- Replies: 5
- Views: 385
Re: significant figures
I'm pretty sure they're all right. Any zeros between two significant digits are significant. Also, a final zero or trailing zeros in the decimal portion only are significant.