Search found 97 matches

Sun Mar 08, 2020 11:38 pm
Forum: Zero Order Reactions
Topic: Not used Half life
Replies: 8
Views: 472

Re: Not used Half life

The half-life for a first order reaction is used because it remains constant for a substance and is independent of reactant concentration.
Sun Mar 08, 2020 11:36 pm
Forum: Zero Order Reactions
Topic: examples of zero order reactions?
Replies: 6
Views: 84

Re: examples of zero order reactions?

A zero order reaction would be an enzymatic reaction in which the enzyme is saturated so the reaction rate does not increase even if the concentration of the reactants increases.
Sun Mar 08, 2020 11:34 pm
Forum: General Rate Laws
Topic: Enzyme saturation
Replies: 6
Views: 82

Re: Enzyme saturation

If an enzyme is saturated, then the reaction rate is not going to increase even if the concentration of reactant increases.
Sun Mar 08, 2020 11:33 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Intermediate Species
Replies: 9
Views: 127

Re: Intermediate Species

An intermediate species is a species that is formed in the middle of the reaction but does not appear in the overall reaction equation or overall reaction rate equation.
Sun Mar 08, 2020 11:32 pm
Forum: General Rate Laws
Topic: First vs Second vs Zero Order
Replies: 7
Views: 81

Re: First vs Second vs Zero Order

A first order reaction is one that is a straight line on the ln[a] vs time graph. A second order reaction is one that is a straight line on the 1/[a] vs time graph.
Sun Mar 08, 2020 11:31 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Notation Layout
Replies: 7
Views: 80

Re: Cell Notation Layout

For a galvanic cell, the oxidation is on the left and the reduction is on the right.
Mon Mar 02, 2020 10:30 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: test 2 topics
Replies: 11
Views: 115

Re: test 2 topics

Will section 6O be on the test because it covers some concepts we didn't go over in class?
Mon Mar 02, 2020 10:29 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: gibbs free energy vs cell standard potential
Replies: 3
Views: 39

Re: gibbs free energy vs cell standard potential

This is because in the equation, deltaG = -nFE, the n compensates for the change in the molar quantities so E has to remain the same for deltaG to change.
Mon Mar 02, 2020 10:28 am
Forum: Balancing Redox Reactions
Topic: Anode and Xathod
Replies: 9
Views: 98

Re: Anode and Xathod

An anode is the site of oxidation and cathode is the site of reduction.
Mon Mar 02, 2020 10:27 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Notation Layout
Replies: 7
Views: 80

Re: Cell Notation Layout

Yes. Typically, you write the oxidation (anode) on the left and the reduction(cathode) on the right.
Mon Mar 02, 2020 10:26 am
Forum: First Order Reactions
Topic: First Order Reaction
Replies: 4
Views: 83

Re: First Order Reaction

A first order reaction is characterized by the linear graph of concentration and time.
Mon Mar 02, 2020 10:24 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Concentration in Cell Notation
Replies: 2
Views: 41

Re: Concentration in Cell Notation

If the question is asking you to find an unknown concentration in the cell diagram, then I would write it as part of it.
Thu Feb 20, 2020 12:00 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: galvanic cell structure
Replies: 8
Views: 51

Re: galvanic cell structure

At the anode, the electrons leave the electrode and migrate to the cathode. Thus, the anode is oxidized while the cathode is reduced.
Wed Feb 19, 2020 11:59 pm
Forum: Balancing Redox Reactions
Topic: Understanding Half-Reactions
Replies: 11
Views: 170

Re: Understanding Half-Reactions

The half-reactions represent the oxidation and reduction reactions. For a species to be reduced, it has to accept electrons from a species that has to be oxidized.
Wed Feb 19, 2020 11:58 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Max Potential
Replies: 5
Views: 55

Re: Max Potential

Maximum voltage occurs right when the switch is closed, which is when there is least current flowing.
Wed Feb 19, 2020 11:57 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Battery Dying
Replies: 4
Views: 74

Re: Battery Dying

The salt bridge allows the charge to be balanced on both sides, therefore it allows the charge to continue transferring.
Wed Feb 19, 2020 11:57 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Replies: 6
Views: 106

A battery goes dead when the reaction inside has reached equilibrium ( the transfer of net charge has stopped).
Wed Feb 19, 2020 11:56 pm
Forum: Balancing Redox Reactions
Topic: Reduction vs. oxidation
Replies: 29
Views: 335

Re: Reduction vs. oxidation

Reduced species are those that gain electrons and oxidized species are those that lose electrons.
Wed Feb 19, 2020 11:55 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Potential difference between electrodes
Replies: 3
Views: 54

Re: Potential difference between electrodes

The maximum voltage occurs just when the switch is closed. This is because voltage is equal to J/Coulomb of charge and since charge is in the denominator, maximum voltage occurs at the least charge.
Wed Feb 19, 2020 11:53 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Replies: 20
Views: 335

Adding an inert gas does not shift the reaction because it doesn't react with any of the reactants or products so the concentrations of each don't change.
Wed Feb 19, 2020 11:52 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Gibbs free energy
Replies: 9
Views: 181

Re: Gibbs free energy

The second one is gibbs free energy measured under standard conditions. This gibbs free energy remains constant throughout the reaction .
Wed Feb 19, 2020 11:51 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Anode and Cathode
Replies: 6
Views: 54

Re: Anode and Cathode

The anode is always oxidized and the cathode is always reduced, so the electron will always travel from the anode to the cathode.
Mon Feb 10, 2020 12:08 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 4D.3
Replies: 2
Views: 39

Re: 4D.3

This is in a bomb calorimeter so volume is constant, so no work is done. delta U is equal to q, which is C(deltaT). C is the capacity of the bomb calorimeter and T is the temperature change given.
Mon Feb 10, 2020 12:04 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: constant pressure system
Replies: 2
Views: 47

Re: constant pressure system

An open system is always constant pressure because the system is exposed to the air which is at constant pressure.
Mon Feb 10, 2020 12:01 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: spontaneity
Replies: 18
Views: 172

Re: spontaneity

a reaction is spontaneous if the total entropy is positive
Mon Feb 10, 2020 12:00 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: spontaneity
Replies: 18
Views: 172

Re: spontaneity

a reaction is spontaneous if the total entropy is positive
Sun Feb 09, 2020 8:33 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: State Functions
Replies: 5
Views: 72

Re: State Functions

The acronym is P D TV HUGS. When your under pressure and depressed, you should watch TV and gets hugs. P = Pressure, D = density, T = temperature, V = volume, H = enthalpy, U = internal E, G = gibbs free energy, and S = entropy. Heat capacity is also a state function.
Mon Jan 27, 2020 8:58 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Chemical Equilibria
Replies: 4
Views: 36

Re: Chemical Equilibria

When a reaction has reached equilibrium, the rate at which products are formed is equal to the rate at which reactants are formed. The concentrations of reactants and products remain constant.
Mon Jan 27, 2020 8:55 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Negative delta H
Replies: 2
Views: 41

Re: Negative delta H

In a reaction, you have both the breaking of bonds and forming of bonds. Therefore, there are energy requirements and energy release involved in a reaction. Just depends on whether the requirement out-weights the release or not.
Mon Jan 27, 2020 8:53 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: q and deltaH
Replies: 3
Views: 28

Re: q and deltaH

delta H is the heat measured under constant pressure.
Mon Jan 27, 2020 8:53 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Ka and Kb
Replies: 10
Views: 108

Re: Ka and Kb

If Ka is less than 10-3, then it is a weak acid. Greater than 10^3 would make it a strong acid.
Mon Jan 27, 2020 8:51 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Specific Heat and Molar Heat Capacity
Replies: 4
Views: 48

Re: Specific Heat and Molar Heat Capacity

Heat capacity is an extensive property while specific heat capacity is an intensive property. Intensive properties are more important to us.
Mon Jan 27, 2020 8:50 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Stirrer in Calorimeter?
Replies: 3
Views: 21

Re: Stirrer in Calorimeter?

The stirrer also helps to homogenize the solution so that the change in temperature is distributed evenly.
Mon Jan 27, 2020 8:49 pm
Forum: Phase Changes & Related Calculations
Topic: Enthalpy Intensive or Extensive
Replies: 4
Views: 136

Re: Enthalpy Intensive or Extensive

Enthalpy is an extensive property. Another extensive property is heat capacity. Specific heat capacity, however, is an intensive property.
Mon Jan 27, 2020 8:48 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Calorimeter
Replies: 7
Views: 87

Re: Calorimeter

A calorimeter is an instrument used to calculate the change in Temperature caused by a reaction and using this change to calculate the enthalpy of reaction.
Mon Jan 27, 2020 8:46 pm
Forum: Phase Changes & Related Calculations
Topic: Enthalpy of sublimation?
Replies: 8
Views: 76

Re: Enthalpy of sublimation?

The enthalpy of sublimation is simply the sum of the heat of fusion and the heat of vaporization.
Mon Jan 20, 2020 6:09 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: q vs k
Replies: 9
Views: 52

Re: q vs k

Q value is calculated when you don't know whether the reaction is at equilibrium or not. If Q equals K, then the reaction is at equilibrium.
Mon Jan 20, 2020 6:09 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Endothermic vs Exothermic
Replies: 7
Views: 78

Re: Endothermic vs Exothermic

An exothermic reaction will have a delta H value that is negative and an endothermic reaction will have a delta H value that is positive.
Mon Jan 20, 2020 6:03 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: definition of a buffer
Replies: 8
Views: 131

Re: definition of a buffer

A buffer is a solution that contains both conjugates. In the ICE table, therefore, the starting concentration for the conjugate acid/base is not 0.
Mon Jan 20, 2020 6:02 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Writing K Expression
Replies: 6
Views: 57

Re: Writing K Expression

Yes, H20 is included in the K equation when it is a gas.
Mon Jan 20, 2020 6:01 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ATP hydrolysis [ENDORSED]
Replies: 3
Views: 48

Re: ATP hydrolysis[ENDORSED]

Because ATP hydrolysis is exergonic, so the products have less energy than the reactants. Thus, the products are more stable than the reactants.
Mon Jan 20, 2020 5:57 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE table and X
Replies: 6
Views: 55

Re: ICE table and X

You eliminate x from the denominator when K is less than 0.001. This is because when K is this small, the change (x) will be less than 5% of the initial concentration.
Sun Jan 12, 2020 9:32 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Q>K
Replies: 9
Views: 82

Re: Q>K

Q is greater than K when there more products than the equilibrium concentration of products.
Sun Jan 12, 2020 9:31 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Calculating Q
Replies: 16
Views: 226

Re: Calculating Q

Calculating Q is the same as calculating K.
Sun Jan 12, 2020 9:29 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Response of Equilibria to Change
Replies: 6
Views: 47

Re: Response of Equilibria to Change

If stress is put on a system, then the reaction shifts in the direction that minimizes that stress.
Sun Jan 12, 2020 9:28 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K and Q
Replies: 10
Views: 72

Re: K and Q

K and Q are different because K represents the reaction at equilibrium whereas Q represents the reaction at a point other than at equilibrium.
Sun Jan 12, 2020 9:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Solids and Liquids
Replies: 6
Views: 50

Re: Solids and Liquids

Solids are not used because you cannot measure the concentration of solids. Liquids are not used because pure liquids are too dilute to affect the K.
Sat Dec 07, 2019 11:17 pm
Forum: Calculating the pH of Salt Solutions
Topic: weak acid/base and pH
Replies: 2
Views: 98

Re: weak acid/base and pH

A weak base will not raise the pH as much as a strong base would and that also goes for weak acids as they are incompletely protonated/deprotonized.
Sat Dec 07, 2019 11:15 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: bond angles
Replies: 16
Views: 228

Re: bond angles

Bond angles will be less than the ideal structure due to lone pair and bond pair repulsion and/or lone-pair lone-pair repulsions.
Sat Dec 07, 2019 11:13 pm
Forum: Air Pollution & Acid Rain
Topic: dirty/clean coal
Replies: 6
Views: 146

Re: dirty/clean coal

Dirty coal has more Sulfur in it while clean coal has less sulfur content and thus more Carbon content.
Sat Dec 07, 2019 11:13 pm
Forum: Biological Examples
Topic: Cisplatin
Replies: 5
Views: 199

Re: Cisplatin

Cis can form two bonds because the Chlorines are on the same side, while in trans they are opposite of each other.
Sat Dec 07, 2019 11:12 pm
Forum: Air Pollution & Acid Rain
Topic: Acid Rain
Replies: 15
Views: 1505

Re: Acid Rain

I don't think we need to know its impact on the environment. We just need to know the chemical equations associated with it and that the primary acid in acid rain is carbonic acid.
Sun Dec 01, 2019 11:31 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Relative Acidity
Replies: 1
Views: 25

Re: Relative Acidity

Relative strength of an acid can be calculated using the Ka value of the acid, assuming the acid is a weak acid. Ka = [H+][A-]/[HA]. The higher the Ka value, the stronger the acid.
Sun Dec 01, 2019 11:28 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: pOH
Replies: 3
Views: 36

Re: pOH

[OH-][H+] = 1x10^14, which is equal to Kw. If we take the -log of each side, we get pOH + pH = 14. Knowing the pOH will allow you to calculate the pH of the solution.
Sun Dec 01, 2019 11:26 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Acid and water
Replies: 2
Views: 41

Re: Acid and water

It is more accurate to use H3O+ in place of H+ because the acid will donate its proton to the water molecule to form H3O+. Calculating pH is the same if you take H3O+ in place of H+.
Sun Dec 01, 2019 11:23 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: pKa and electronegativity
Replies: 2
Views: 54

Re: pKa and electronegativity

In binary acids H-A, the greater the electron affinity and thus the electronegativity of the A element, the more polarizing the molecule and thus, the Hydrogen is more easily lost to a proton acceptor and thus, its Ka value will be greater and pKa will be smaller compared to that of a binary acid in...
Sun Dec 01, 2019 11:20 pm
Forum: Lewis Acids & Bases
Topic: Difference between Lewis and Bronsted
Replies: 4
Views: 37

Re: Difference between Lewis and Bronsted

Lewis acids accept electron pairs and Lewis bases donate electron pairs while Bronsted acids donate protons and Bronsted bases accept protons. Lewis acids includes the proton while Bronsted only considers compounds as acidic if they supply protons.
Sun Dec 01, 2019 11:18 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Acids Vs. Bases
Replies: 11
Views: 174

Re: Acids Vs. Bases

Acid and Base classification differs depending on whether you are discussing Arrhenius, Bronsted, or Lewis acids and bases. Arrhenius acids form H+ ions in water, while bases form OH- ions in water. Bronsted acids donate protons while Bronsted bases accept protons. Lewis acids accept electron pairs ...
Sun Nov 24, 2019 11:47 pm
Forum: Hybridization
Topic: Sigma and Pi Bonds
Replies: 21
Views: 188

Re: Sigma and Pi Bonds

All single bonds are sigma bonds. In double or triple bonds, there is one sigma bond and the rest are pi.
Sun Nov 24, 2019 11:43 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bond Order
Replies: 8
Views: 127

Re: Bond Order

If a bond order is zero, that means that the molecule is too unstable and it will not exist.
Sun Nov 24, 2019 11:31 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Cis vs Trans
Replies: 22
Views: 532

Re: Cis vs Trans

cis indicates that the functional groups are on the same side of the carbon chain while trans conveys that functional groups are on opposing sides of the carbon chain
Sun Nov 24, 2019 11:26 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 7
Views: 145

Re: Bond Angles

If the atoms bonded to the central atom are not the same, the size and electron distribution around the atoms will differ which will affect the distribution of the electrons on the other atoms, which will affect the bond angle.
Sun Nov 24, 2019 11:24 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Hydrogen Bonding
Replies: 2
Views: 47

Re: Hydrogen Bonding

A lone pair is a potential site for hydrogen bonding. Hydrogen bonding can also be possible when hydrogen is near a nitrogen, oxygen, or fluorine atom.
Sun Nov 17, 2019 9:53 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 7
Views: 109

Re: Bond Angles

Lone pair - lone pair repulsion is stronger than lone-pair bond pair which is stronger than bond pair-bond pair, regardless of whether it involves a cation, anion, or molecule.
Sun Nov 17, 2019 9:51 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: vsepr angles
Replies: 10
Views: 76

Re: vsepr angles

You should memorize the different orientations and their bond angles as it will be useful for the upcoming test.
Sun Nov 17, 2019 9:51 pm
Forum: Dipole Moments
Topic: Effects for boiling point
Replies: 5
Views: 69

Re: Effects for boiling point

Boiling point increases when the strength of the intermolecular force increases. For instance, molecules that have induced-dipole attraction have a lower boiling point that molecules that interact through ionic interactions.
Sun Nov 17, 2019 9:49 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: covalent forces
Replies: 1
Views: 24

Re: covalent forces

A non-covalent interaction is different from covalent because it does not involve the sharing of electrons, but instead has more dispersed variations of electromagnetic interactions between or within molecules.
Sun Nov 17, 2019 9:48 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: intermolecular forces
Replies: 2
Views: 21

Re: intermolecular forces

induced dipole-dipole are not permanent forces. They are temporary dipoles that have been induced by a neighboring molecule. Also, most intermolecular forces are not permanent.
Sat Nov 09, 2019 11:34 pm
Forum: Sigma & Pi Bonds
Topic: One Sigma One Pi
Replies: 3
Views: 58

Re: One Sigma One Pi

Two sigma bonds are not possible because the orbitals overlap end-to-end in a sigma bond. In order to form another bond to share more electrons, it is only possible for their orbitals to overlap side-to-side to form a pi bond.
Sat Nov 09, 2019 11:14 pm
Forum: Hybridization
Topic: Pi vs Sigma Bonds
Replies: 4
Views: 56

Re: Pi vs Sigma Bonds

Pi bonds are weaker than sigma bonds because the of the parallel orbital paths which mean less overlap between the p-orbitals. Pi bonds happen when two atomic orbitals are in contact through two areas of overlap. Pi bonds are also more spread out than sigma bonds.
Sat Nov 09, 2019 11:10 pm
Forum: Ionic & Covalent Bonds
Topic: Comparing Strengths of Ionic & Covalent Bonds
Replies: 2
Views: 55

Re: Comparing Strengths of Ionic & Covalent Bonds

When aqueous environment, covalent bond are stronger than ionic bonds because compounds held together by ionic bonds tend to dissolve in water and dissociate into the individual ions whereas the molecules in molecular compounds do not break up when in water.
Sat Nov 09, 2019 11:03 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angle
Replies: 2
Views: 31

Re: Bond Angle

The lone pairs are delocalized whereas the electrons in a bond are not free to move as much. Therefore, the repulsions between the electrons in lone pairs can distort the electron cloud.
Sat Nov 09, 2019 10:50 pm
Forum: Electronegativity
Topic: Ionization Energy
Replies: 3
Views: 51

Re: Ionization Energy

Nitrogen also has a lower IE because it has half-filled p subshell which is more stable than the 4 electron configuration in the p orbital of oxygen.
Sun Nov 03, 2019 9:51 pm
Forum: Properties of Electrons
Topic: Electrons
Replies: 1
Views: 153

Re: Electrons

In a many electron system, the orbitals within a shell differ in their energies. This difference is attributed to electron-electron repulsions within the orbitals. This is different from a one electron system, in which the orbitals within a shell are degenerate (are of the same energies).
Sun Nov 03, 2019 9:49 pm
Forum: *Shrodinger Equation
Topic: Schrodinger's Equation
Replies: 1
Views: 125

Re: Schrodinger's Equation

Electrons have wave-particle duality. Schrodinger equation is used to represent the wave-like characteristic of electrons. The square of the wave function represents the probability density of finding an electron in a particular space.
Sun Nov 03, 2019 9:47 pm
Forum: Octet Exceptions
Topic: d-Orbitals
Replies: 2
Views: 47

Re: d-Orbitals

Usually you can tell if you need the incomplete octet when the number of total electrons doesn't equal the total number of electrons in the structure and you cant accommodate with more bonds.
Sun Nov 03, 2019 9:43 pm
Forum: Bond Lengths & Energies
Topic: Bond Strength and Electronegativity
Replies: 3
Views: 46

Re: Bond Strength and Electronegativity

What is the trend of electronegativity in terms of the periodic table? Does electronegativity increase as you go towards the right of the periodic table? The trend for electronegativity is that it increases diagonally from bottom left to the top right. Flourine, therefore, is the most electronegati...
Sun Nov 03, 2019 9:41 pm
Forum: Formal Charge and Oxidation Numbers
Topic: formal charge
Replies: 5
Views: 78

Re: formal charge

Formal charge is calculated by subtracting the number of bonds plus the number of free electrons from the number of valence electrons of that atom. The sum of the number of bonds plus the number of free electrons can be thought of as the sum of the number of sticks (bonds) and dots (electrons).
Sun Oct 27, 2019 12:13 am
Forum: Quantum Numbers and The H-Atom
Topic: Quantum Numbers
Replies: 7
Views: 110

Re: Quantum Numbers

Electron spins affect an electron's behavior because it prevents two electrons with parallel spins from occupying the same orbital. The configuration is most stable when electrons are paired with electrons with opposite spins.
Sun Oct 27, 2019 12:10 am
Forum: Trends in The Periodic Table
Replies: 2
Views: 32

The atomic radius is measured by halving the inter-nuclear distance between two like atoms. This is what the Angstrom represents.
Sun Oct 27, 2019 12:08 am
Forum: Formal Charge and Oxidation Numbers
Topic: Lowering Formal Charge
Replies: 6
Views: 131

Re: Lowering Formal Charge

The arrangement that allows for the lowest formal charge is the one that matches closest to the true structure. Also, it is important to remember that the atom with the lower electron affinity should not get the most negative formal charge.
Sun Oct 27, 2019 12:05 am
Forum: Trends in The Periodic Table
Topic: Aufbau Principle
Replies: 11
Views: 142

Re: Aufbau Principle

Can someone explain how to set this up so that you can get to the electron configuration. I understand that you want to fill the shells so that they become more stable and how to put in the spin state but what is the order that you fill in the shells? You fill the shells in order of increasing ener...
Sun Oct 27, 2019 12:00 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Same spin
Replies: 10
Views: 157

Re: Same spin

Aprice_1J wrote:When would you see them have parallel spins? If they are more stable with different spins, what would constitute them having the same spin?

Electrons with the same spin cannot occupy the same orbital. Electrons singly occupy the different orbitals with parallel spins (Hund's Rule).
Wed Oct 16, 2019 10:02 pm
Forum: Quantum Numbers and The H-Atom
Topic: Stern and Gerlach
Replies: 5
Views: 61

Re: Stern and Gerlach

The difference in spin only shows up in the presence of a magnetic field. In the absence of magnetic field, the electron spins have the same energy, however, this is not the case when the atom beam of silver ions passed through a magnetic field in the experiment.
Wed Oct 16, 2019 10:01 pm
Forum: *Shrodinger Equation
Topic: Hamiltonian
Replies: 1
Views: 41

Re: Hamiltonian

If a wave equation represents electrons, a change in the wave function will give the energy associated with the wave function. The double derivative of the wave function allows us to return to the original equation. For example, when we take the derivative of sinx, we get cosx, and when we take the ...
Wed Oct 16, 2019 9:55 pm
Forum: Properties of Electrons
Topic: The wave property of electrons [ENDORSED]
Replies: 2
Views: 54

Re: The wave property of electrons[ENDORSED]

If electrons only acted as particles, there would be no diffraction pattern. The electrons would have been detected in one spot as opposed to more than one.
Wed Oct 16, 2019 9:50 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Subshell and orbital clarification
Replies: 1
Views: 39

Re: Subshell and orbital clarification

The number of orbitals are usually found using the magnetic quantum number, m subscript l. For example, the quantum number l = 1 would have ml equal to -1, 0, 1 which corresponds to 3 p orbitals. The p is found based on the value of l. A value of 0 corresponds to s orbital, 1 to p orbital, 2 to d or...
Wed Oct 16, 2019 9:45 pm
Forum: Quantum Numbers and The H-Atom
Topic: Schrodinger's Wave Equation
Replies: 2
Views: 43

Re: Schrodinger's Wave Equation

It applies to one electron systems only because for one electron systems, the different energy levels are degenerate, or equal in energy. However, for multi-electron systems, this is not true.
Sun Oct 13, 2019 6:53 pm
Forum: Properties of Light
Topic: Visualizing wave-particle duality
Replies: 3
Views: 75

Re: Visualizing wave-particle duality

The wavelength of light is different from the wavelength of a photon/electron. The equation for light is c = wavelength x frequency, whereas, the equation for wavelength of an electron is wavelength = h (Planck's constant)/p (momentum).
Sun Oct 13, 2019 6:50 pm
Forum: Properties of Light
Topic: 'light intensity'
Replies: 8
Views: 87

Re: 'light intensity'

Black body refers to anything that absorbs all forms of electromagnetic radiation, regardless of frequency.
Sun Oct 13, 2019 6:48 pm
Forum: Properties of Light
Topic: Quanta- clear up comparison
Replies: 3
Views: 50

Re: Quanta- clear up comparison

The example relates to quanta because in the quantum world, energy is assumed to be in quantized, or discreet amounts rather than being continuous. On the surface, the water from the bucket looks like it is flowing in one continuous motion. However, when you are on the molecular level, water is comi...
Sun Oct 13, 2019 6:45 pm
Forum: Properties of Light
Topic: P.E Experiment
Replies: 3
Views: 69

Re: P.E Experiment

When an electron moves from a higher energy level to a lower energy level, it emits or releases energy. The release of energy is associated with a more stable state. Transitioning from n=4 to n=2 allows the electron to achieve a more stable state, and thus, it emits energy.
Sun Oct 13, 2019 6:42 pm
Forum: Properties of Light
Topic: Wave vs particle properties
Replies: 4
Views: 79

Re: Wave vs particle properties

It is also important to remember that equations for electromagnetic radiation (waves) cannot be directly applied to equations for measuring wavelength associated with an electron. For example, the equation: c = lamda x frequency cannot be used to solve for the electron's wavelength. There is a separ...
Wed Oct 02, 2019 5:18 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Tips on how to write a formula out from the name
Replies: 9
Views: 212

Re: Tips on how to write a formula out from the name

There's a list of strong acids and bases in the textbook which would come in handy for some of the problems, so I suggest memorizing them. Learning these would also help with understanding the nomenclature pattern of acids/bases and the ions involved.
Wed Oct 02, 2019 5:11 pm
Forum: Molarity, Solutions, Dilutions
Topic: General Rounding Question
Replies: 9
Views: 85

Re: General Rounding Question

Try to avoid rounding until the very end when you have to give the answer with the correct number of significant figures, which is the least number of significant figures among the numbers given in the question.
Wed Oct 02, 2019 5:07 pm
Forum: Limiting Reactant Calculations
Topic: Other Way to Find the Limiting Reactant [ENDORSED]
Replies: 3
Views: 96

Re: Other Way to Find the Limiting Reactant[ENDORSED]

To find the limiting reactant, I find it helpful to calculate the number of moles of other reactants required for each reactant and then comparing that value to the number of moles that actually exist for each reactant.
Wed Oct 02, 2019 12:53 am
Forum: SI Units, Unit Conversions
Topic: Writing chemical equations
Replies: 2
Views: 116

Re: Writing chemical equations

Chemical equations can be divided up into combination, decomposition, single displacement, double displacement, combustion, and redox reactions. Combination involves two or more reactants that form one product and decomposition is the reverse of that. In single displacement, the more active element ...