Search found 97 matches

by Rhea Shah 2F
Sun Mar 15, 2020 11:54 pm
Forum: Van't Hoff Equation
Topic: Entropy
Replies: 2
Views: 43

Entropy

Can we use the van't hoff equation to calculate entropy, or would we use a different equation to calculate entropy over a temperature change?
by Rhea Shah 2F
Sun Mar 15, 2020 11:52 pm
Forum: Balancing Redox Reactions
Topic: Ecell values
Replies: 12
Views: 85

Re: Ecell values

The more positive E cell value corresponds to the reaction that is reduced. This reaction occurs at the cathode.
by Rhea Shah 2F
Sun Mar 15, 2020 11:50 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: concentration
Replies: 3
Views: 30

concentration

Why does changing the concentration of the oxidized/reduced element change the cell potential?
by Rhea Shah 2F
Sun Mar 15, 2020 11:41 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: ΔGionization
Replies: 8
Views: 70

Re: ΔGionization

I don't think so! It should be the same as the regular way of calculating standard gibbs free energy.
by Rhea Shah 2F
Sun Mar 15, 2020 11:41 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free Energy Ionization
Replies: 2
Views: 28

Re: Gibbs Free Energy Ionization

You just use the ionization constant and plug that into the -RTlnK equation. It's the same as calculating the regular gibbs free energy.
by Rhea Shah 2F
Sun Mar 15, 2020 11:32 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Electrode size [ENDORSED]
Replies: 2
Views: 29

Electrode size [ENDORSED]

Does changing the electrode size change the standard potential of the cell?
by Rhea Shah 2F
Sun Mar 15, 2020 11:31 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Activation Energy
Replies: 4
Views: 24

Activation Energy

How do you figure out the rate of a reaction based on the graphs of the activation energy?
by Rhea Shah 2F
Sun Mar 08, 2020 8:05 pm
Forum: Balancing Redox Reactions
Topic: Balancing basic reactions
Replies: 8
Views: 42

Balancing basic reactions

How do I know which side to add OH- to and which side to add H20 to?
by Rhea Shah 2F
Sun Mar 08, 2020 8:04 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Vertical lines vs commas
Replies: 7
Views: 24

Vertical lines vs commas

How do you know when to add vertical lines in between the components of a cell diagram, versus when to add commas?
by Rhea Shah 2F
Sun Mar 08, 2020 8:03 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Platinum
Replies: 10
Views: 36

Platinum

When do you know when to add platinum or another solid element to the cell diagram?
by Rhea Shah 2F
Sun Mar 08, 2020 8:02 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: K < >
Replies: 8
Views: 41

Re: K < >

Knowing K is helpful in determining in which direction the reaction is favored. If the E of a cell is greater than 0, then K is less than 1, and the opposite if true if E is less than 0.
by Rhea Shah 2F
Sun Mar 08, 2020 7:59 pm
Forum: General Rate Laws
Topic: units
Replies: 12
Views: 45

units

How do I determine the units of k for a reaction?
by Rhea Shah 2F
Sun Mar 01, 2020 11:07 pm
Forum: General Rate Laws
Topic: Order
Replies: 5
Views: 53

Order

How do you know which order rate law to use for a reaction?
by Rhea Shah 2F
Sun Mar 01, 2020 11:06 pm
Forum: First Order Reactions
Topic: Graph
Replies: 9
Views: 69

Graph

What should the graph of an ln reactant vs. time plot look like for first order reaction?
by Rhea Shah 2F
Sun Mar 01, 2020 11:05 pm
Forum: General Rate Laws
Topic: tangent lines
Replies: 5
Views: 55

Re: tangent lines

Yes, that's the easiest way to find the instantaneous rate for reactions. You could also just take the average rate over a very small time interval.
by Rhea Shah 2F
Sun Mar 01, 2020 11:03 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: units
Replies: 11
Views: 78

units

What are the units for the rate of the reaction?
by Rhea Shah 2F
Sun Mar 01, 2020 11:02 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: instantaneous rate
Replies: 16
Views: 111

instantaneous rate

Why do we use the instantaneous rate instead of the average rate?
by Rhea Shah 2F
Sun Feb 23, 2020 11:07 pm
Forum: Balancing Redox Reactions
Topic: Oxidation?
Replies: 10
Views: 57

Re: Oxidation?

The atom that is oxidized has lost electrons, so look for the atom whose charge has increased.
by Rhea Shah 2F
Sun Feb 23, 2020 11:04 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagrams
Replies: 2
Views: 36

Re: Cell Diagrams

The anode is on the left, and contains the oxidation half-reaction. The right side is the cathode, which contains the reduction half-reaction. The salt bridge connects both cells and allows for the transfer of ions between the cells.
by Rhea Shah 2F
Sun Feb 23, 2020 11:01 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Standard Hydrogen Electrode
Replies: 3
Views: 23

Re: Standard Hydrogen Electrode

We can't measure the transfer of electrons for one cell, so we have to compare the electron transfers of all cells. Thus, we need a standardized value to compare it to, which is why we use the values obtained from a standard reaction electrode.
by Rhea Shah 2F
Sun Feb 23, 2020 10:59 pm
Forum: Balancing Redox Reactions
Topic: Acids and Bases
Replies: 4
Views: 49

Acids and Bases

How do we know which side to add the H+/OH- to? And do we add water to the opposite side?
by Rhea Shah 2F
Sun Feb 23, 2020 10:58 pm
Forum: Balancing Redox Reactions
Topic: Reduction?
Replies: 13
Views: 84

Re: Reduction?

Whichever atom's charge gets smaller is the one that is reduced
by Rhea Shah 2F
Sun Feb 16, 2020 10:16 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Delta G equations
Replies: 4
Views: 43

Delta G equations

What is the difference between the main delta G equations? How do you know which one to use?
by Rhea Shah 2F
Sun Feb 16, 2020 10:15 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: isothermal reactions
Replies: 8
Views: 103

isothermal reactions

Why is internal energy equal to 0 in an isothermal reaction?
by Rhea Shah 2F
Sun Feb 16, 2020 10:14 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Delta s = 0
Replies: 8
Views: 107

Re: Delta s = 0

Delta s is 0 when the reaction is either isothermal or reversible.
by Rhea Shah 2F
Sun Feb 16, 2020 10:14 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Cv vs Cp
Replies: 17
Views: 167

Re: Cv vs Cp

Cv is used when volume is held constant, and is equal to 3/2R. Cp is used when pressure is held constant and is equal to 5/2R
by Rhea Shah 2F
Sun Feb 16, 2020 10:12 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: S = 0
Replies: 18
Views: 163

Re: S = 0

In an isothermal reaction, the change in surrounding entropy is zero because energy is not transferred to the surroundings. In a reversible reaction, the total entropy change is equal to zero because the system is in equilibrium.
by Rhea Shah 2F
Mon Feb 10, 2020 8:47 pm
Forum: Calculating Work of Expansion
Topic: Reversible Reactions
Replies: 2
Views: 22

Reversible Reactions

Why is it that the greatest work that is done for a process is the work that takes place reversibly?
by Rhea Shah 2F
Mon Feb 10, 2020 8:46 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: types of heat capacities
Replies: 3
Views: 37

types of heat capacities

What is the difference between heat capacity, specific heat capacity, and molar heat capacity?
by Rhea Shah 2F
Mon Feb 10, 2020 8:38 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: pH
Replies: 3
Views: 45

Re: pH

Acid strength is classified by concentration of hydrogen ions. Weak acids do not dissociate completely in water while stronger acids do. Thus, stronger acids produce more hydrogen ions, which lowers the pH of these acids, while the pH of weak acids is higher due to the lower concentration of H+ ions
by Rhea Shah 2F
Mon Feb 10, 2020 8:33 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: types of disorder
Replies: 2
Views: 15

types of disorder

Could someone explain the difference between positional disorder and residual disorder?
by Rhea Shah 2F
Mon Feb 10, 2020 8:31 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Spontaneous delta G
Replies: 7
Views: 30

Re: Spontaneous delta G

a reaction is spontaneous if delta G is less than zero. thus, we set the equation for gibbs free energy equal to 0 to find the temperature at which delta g changes sign and becomes negative. the temperature at which delta g is 0 is the temperature at which the two phases coexist, so the temperature ...
by Rhea Shah 2F
Sun Feb 02, 2020 9:45 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: States of a system
Replies: 3
Views: 29

States of a system

How do you calculate the amount of microstates possible for a certain system?
by Rhea Shah 2F
Sun Feb 02, 2020 9:42 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: negative delta U value
Replies: 2
Views: 18

Re: negative delta U value

We must also know thee entropy of the system. Entropy describes the different microscopic configurations of the system, so it's a necessary property to know when calculating whether the system is in a particular state.
by Rhea Shah 2F
Sun Feb 02, 2020 9:38 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Internal Energy of isolated system
Replies: 2
Views: 12

Re: Internal Energy of isolated system

An isolated system has a constant internal energy because no matter or heat can be physically exchanged with the system. In other terms, the heat and work of the system can't be changed, thee internal energy remains constant.
by Rhea Shah 2F
Sun Feb 02, 2020 9:36 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: U
Replies: 4
Views: 35

Re: U

Internal energy is the energy necessary to create or prepare the state of the system, and is calculate by taking H (the enthalpy) and subtracting the pressure times the change in volume of the system.
by Rhea Shah 2F
Sun Feb 02, 2020 9:31 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Changing energy
Replies: 2
Views: 35

Changing energy

Can someone explain the ways of changing the energy in a system?
by Rhea Shah 2F
Sun Jan 26, 2020 10:46 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Pure solids & liquids
Replies: 5
Views: 35

Re: Pure solids & liquids

pure solids and liquids are not dissolved in another substance. in a chemical equation, these are denotes with either (s) or (l), telling us that the substance is a pure solid or liquid and should be excluded from the equilibrium constant calculation. Pure solids and liquids are also most in their m...
by Rhea Shah 2F
Sun Jan 26, 2020 10:40 pm
Forum: Phase Changes & Related Calculations
Topic: Phase changes
Replies: 8
Views: 53

Re: Phase changes

Although the temperature of a sample remains the same, heat is being supplied in order to provide the energy needed for a phase change. This is why the heating curve for water is horizontal at times. In calculations, the enthalpy for the phase change must be added to the bond enthalpies in order to ...
by Rhea Shah 2F
Sun Jan 26, 2020 10:34 pm
Forum: Phase Changes & Related Calculations
Topic: Standard State
Replies: 1
Views: 25

Standard State

if a substance is not in its standard state, what must be done to calculate the enthalpy of the reaction?
by Rhea Shah 2F
Sun Jan 26, 2020 10:32 pm
Forum: Phase Changes & Related Calculations
Topic: Hess's Law
Replies: 8
Views: 39

Re: Hess's Law

Since enthalpy is a state function, it can be added and subtracted. This is applied in Hess's law, which states that the total enthalpy change of a reaction is the sum of all the changes in the reaction, regardless of the number of steps taken to obtain the final product.
by Rhea Shah 2F
Sun Jan 26, 2020 10:29 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: state functions
Replies: 4
Views: 249

Re: state functions

State properties are not dependent on the path taken to obtain that state, and consist of properties such as altitude, pressure, volume, and internal energy.
by Rhea Shah 2F
Sun Jan 19, 2020 5:04 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: pKa
Replies: 13
Views: 70

pKa

What is the relationship between pKa and strength of the acid?
by Rhea Shah 2F
Sun Jan 19, 2020 5:02 pm
Forum: Ideal Gases
Topic: concentration
Replies: 5
Views: 25

concentration

How do you calculate the concentration of a gas if given the partial pressure?
by Rhea Shah 2F
Sun Jan 19, 2020 4:59 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: temperature change in reactions
Replies: 2
Views: 17

temperature change in reactions

Why does K change when the temperature changes in a reaction?
by Rhea Shah 2F
Sun Jan 19, 2020 4:57 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: conjugate seesaw
Replies: 4
Views: 32

conjugate seesaw

Could someone explain the reasoning behind the conjugate seesaw?
by Rhea Shah 2F
Sun Jan 19, 2020 4:56 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: % Ionization
Replies: 3
Views: 17

% Ionization

What is the % ionization of an acid/base?
by Rhea Shah 2F
Thu Jan 09, 2020 6:02 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: solids and liquids
Replies: 6
Views: 38

solids and liquids

why are solids and liquids not included in calculations to determine the equilibrium constant?
by Rhea Shah 2F
Thu Jan 09, 2020 5:58 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K
Replies: 3
Views: 32

Re: K

Since he gave us the ideal gas law and showed us how concentration relates to the partial pressure, I would convert the aqueous solution concentrations to partial pressure and calculate K that way.
by Rhea Shah 2F
Thu Jan 09, 2020 5:56 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Reaction quotient
Replies: 8
Views: 49

Reaction quotient

I'm sure this has been asked before, but could someone explain how K and Q have different values even though the same principle is used to calculate both?
by Rhea Shah 2F
Thu Jan 09, 2020 5:55 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Homework Question 5H.1
Replies: 2
Views: 29

Re: Homework Question 5H.1

Since the coefficient of the reactant/product is the exponent of the concentration/partial pressure in the equilibrium constant, changing the coefficients in the reaction will alter the exponents in the equilibrium constant. Thus, in b, since the coefficients were cut in half, the exponents to which...
by Rhea Shah 2F
Thu Jan 09, 2020 5:52 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5G.11
Replies: 4
Views: 33

Re: 5G.11

Since pure solids and liquids do not affect the equilibrium constant, they are not included in the answer. Thus, there's a one in the numerator instead of the concentrations of the products.
by Rhea Shah 2F
Sun Dec 01, 2019 11:17 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: pKa and electronegativity
Replies: 2
Views: 27

pKa and electronegativity

What is the relationship between the electronegativity of an atom in a molecule and the pKa?
by Rhea Shah 2F
Sun Dec 01, 2019 11:15 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: charge and coordination number
Replies: 2
Views: 19

charge and coordination number

What is the relationship between charge and coordination number?
by Rhea Shah 2F
Sun Dec 01, 2019 11:13 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate
Replies: 2
Views: 35

Re: Polydentate

A polydentate occurs when a ligand binds at more than one binding site, meaning it donates more than one electron pair.
by Rhea Shah 2F
Sun Dec 01, 2019 11:12 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligand Bonding
Replies: 2
Views: 33

Re: Ligand Bonding

Yes, ligands must have one or more lone pairs, and will bind at more than one site of multiple lone pairs are available.
by Rhea Shah 2F
Sun Dec 01, 2019 11:11 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Determing Coordination Number
Replies: 5
Views: 36

Re: Determing Coordination Number

The coordination number is the number of bonds attached to the central ion in the coordination sphere
by Rhea Shah 2F
Sun Nov 24, 2019 11:13 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: coordination sphere
Replies: 3
Views: 51

coordination sphere

what is the coordination sphere of a coordination compound?
by Rhea Shah 2F
Sun Nov 24, 2019 11:10 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination complexes
Replies: 3
Views: 33

Re: Coordination complexes

A coordination complex consists of a ligand and a transition metal cation that share a coordinate covalent bond. Ligands are lewis bases while the transition metals are lewis acids.
by Rhea Shah 2F
Sun Nov 24, 2019 11:05 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Chelate
Replies: 4
Views: 30

Re: Chelate

Chelate complexes consist of a bond between a polydentate ion and a central metal ion. Chelating ligands can bind cations very tightly.
by Rhea Shah 2F
Sun Nov 24, 2019 11:01 pm
Forum: Naming
Topic: oxidation number
Replies: 1
Views: 22

oxidation number

Can someone please explain how to find the oxidation number of an element?
by Rhea Shah 2F
Sun Nov 24, 2019 11:00 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: bronsted acid
Replies: 5
Views: 41

Re: bronsted acid

A bronstead acid is a proton donor that accepts an electron pair. Examples of these are hydrochloric acid or hydrobromic acid.
by Rhea Shah 2F
Sun Nov 17, 2019 5:13 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: Hydrogen Bonding
Replies: 5
Views: 38

Re: Hydrogen Bonding

Hydrogen bonding occurs between molecules with an N-H, O-H, or F-H bond, and doesn't occur within the molecule with this bond. The hydrogen bond forms between the hydrogen of one of these molecules and the electronegative atom of another molecule.
by Rhea Shah 2F
Sun Nov 17, 2019 5:10 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: identifying forces
Replies: 2
Views: 32

Re: identifying forces

You have to look at the types of molecules/ions involved. Ion-dipole interaction occurs between ions and a polar molecule. Dipole-dipole interactions occur between polar molecules. London dispersion forces occur between all molecules and ions. Hydrogen bonding occurs between molecules containing an ...
by Rhea Shah 2F
Sun Nov 17, 2019 5:07 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Repulsion Strength
Replies: 4
Views: 34

Re: Repulsion Strength

Because lone pairs are more loosely held, they have a stronger repelling effect than do electrons in bonds. Thus, lone pair-lone pair interactions have a stronger effect than do lone pair-bond or bond-bond interactions.
by Rhea Shah 2F
Sun Nov 17, 2019 5:04 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: linear versus angular
Replies: 5
Views: 49

Re: linear versus angular

When describing molecular geometry, lone pairs and bonds are included in the description. When describing shape of a molecule, only bonds are taken into account. Thus, lone pairs and bonds within the molecule are responsible for determining whether a molecule is linear or bent.
by Rhea Shah 2F
Sun Nov 17, 2019 5:00 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: geometric angles
Replies: 4
Views: 26

Re: geometric angles

Geometric angles in bonds are experimentally found. You can memorize the angles for each molecular shape, but each angle varies slightly as a result of lone pair interactions that are unique to each molecule. We're not expected to memorize the angles, but just know how to determine whether one angle...
by Rhea Shah 2F
Sun Nov 10, 2019 6:57 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: interactions
Replies: 2
Views: 34

interactions

Is there a difference between the dipole-dipole interaction and induced dipole-induced dipole interactions?
by Rhea Shah 2F
Sun Nov 10, 2019 6:54 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: States of matter
Replies: 2
Views: 30

Re: States of matter

The stronger the IMFs, the more likely the chemical is to stay in a solid or liquid state. The stronger IMFs make it more difficult for the matter to reach its melting or boiling point and transition between different states of matter.
by Rhea Shah 2F
Sun Nov 10, 2019 6:52 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: Structure and bond type
Replies: 2
Views: 24

Re: Structure and bond type

If two atoms have a bond in which they share electrons, then you know that they are covalently bonded. If electrons are merely being donated from one atom to another, they share an ionic bond. The dipole moment is typically represented by an arrow pointing to the more electronegative atom, demonstra...
by Rhea Shah 2F
Sun Nov 10, 2019 6:48 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: How to Draw Dipole Arrows
Replies: 8
Views: 92

Re: How to Draw Dipole Arrows

Dipole moments occur in any bond in which the atoms have a difference in electronegativity. The greater the difference in electronegativity, the greater the dipole moment. The arrow in the dipole moment always points to the more electronegative atom because this is the direction in which the electro...
by Rhea Shah 2F
Sun Nov 10, 2019 6:44 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: Strengths of bonds
Replies: 3
Views: 31

Re: Strengths of bonds

Bond strength is dependent on a variety of factors. The greater the bond the number, the stronger the bond, meaning that a triple bond is stronger than a single bond. Resonance also stabilizes a chemical structure, and increases the strength of the bonds in the molecule. Lone pairs on the atoms repe...
by Rhea Shah 2F
Sat Nov 02, 2019 5:57 pm
Forum: Trends in The Periodic Table
Topic: Trends
Replies: 2
Views: 38

Re: Trends

Ionization energy increases as you move up and right on the periodic table because these atoms have a smaller atomic radius due to the strong nuclear charge on the electrons. Thus, it would require more energy to remove and electron due to the stronger pull on the electrons. This trend is also true ...
by Rhea Shah 2F
Sat Nov 02, 2019 5:50 pm
Forum: Trends in The Periodic Table
Topic: Ionic radius
Replies: 2
Views: 31

Ionic radius

Is there a difference between ionic radius and atomic radius? How do you find which isoelectric ion has a larger ionic radius?
by Rhea Shah 2F
Sat Nov 02, 2019 5:49 pm
Forum: Trends in The Periodic Table
Topic: Period Trends
Replies: 4
Views: 38

Re: Period Trends

There is also a trend for atomic radius. The trend for this is that the radius tends to decrease across and period and increase down a group.
by Rhea Shah 2F
Sat Nov 02, 2019 5:48 pm
Forum: Quantum Numbers and The H-Atom
Topic: 4th Quantum Number
Replies: 3
Views: 31

Re: 4th Quantum Number

The fourth quantum number isn't found, but is rather assigned to an electron in that specific orbital. The fourth number is spin, and there are only two possible values for it: +1/2 and -1/2. No two electrons in an atom can have the same set of 4 quantum numbers, so if there are 2 electrons with the...
by Rhea Shah 2F
Sat Nov 02, 2019 5:42 pm
Forum: Ionic & Covalent Bonds
Topic: Covalent character in ionic bonds
Replies: 3
Views: 53

Re: Covalent character in ionic bonds

Certain ions have high polarizing power, meaning they cause larger distortions in a bond. Ions with high polarizing power pull electrons into the bonding region, which results in an ionic bond with more covalent character.
by Rhea Shah 2F
Sat Oct 26, 2019 5:36 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic Compounds
Replies: 6
Views: 91

Re: Ionic Compounds

Ionic compounds are often between a metal and a nonmetal, in which the metal gives electrons to the nonmetal in order for both elements to obtain a completely filled outer shell. Covalent bonds are between two nonmetals, and in these, electrons are shared, meaning the two electrons in the covalent b...
by Rhea Shah 2F
Sat Oct 26, 2019 5:25 pm
Forum: Ionic & Covalent Bonds
Topic: Covalent Bonds
Replies: 5
Views: 78

Re: Covalent Bonds

Cations form when an atom loses at least one electron, which results in a positive charge. These occur in metals, which typically have between 1-3 valence electrons. These elements lose electrons to become more stable, as they reach a lower valence shell with 8 valence electrons. Nonmetals don't los...
by Rhea Shah 2F
Sat Oct 26, 2019 5:19 pm
Forum: Electronegativity
Topic: The dipole moment
Replies: 2
Views: 46

Re: The dipole moment

The dipole moment is a result of differences in electronegativity in molecule. The greater the electronegativity difference, the greater the dipole moment. Thus, when one atom is more electronegative then the other, a dipole moment occurs as a result of the positive and negative charges formed when ...
by Rhea Shah 2F
Sat Oct 26, 2019 5:14 pm
Forum: Ionic & Covalent Bonds
Topic: Electronegativity
Replies: 4
Views: 57

Re: Electronegativity

Electronegativity is the tendency for an atom to attract an electron in a shared bond, while the ionization energy is the energy needed to remove an electron from an atom in its gas phase. The trends for both are the same on the periodic table, increasing the further one goes to the right and upward...
by Rhea Shah 2F
Sat Oct 26, 2019 5:06 pm
Forum: Bond Lengths & Energies
Topic: Bond length strength
Replies: 6
Views: 76

Re: Bond length strength

The bond length will be supplied to you on a test. However, it's important to remember that double bonds are shorter than single bonds, and double bonds are also stronger than single bonds as well.
by Rhea Shah 2F
Sun Oct 20, 2019 4:16 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: What is Z eff e?
Replies: 3
Views: 39

Re: What is Z eff e?

Z eff e is the effective nuclear charge experienced by an electron. Since other electrons in the atom increase the repulsive interactions within the atom, the effective nuclear charge experienced by an electron is less than the actual nuclear charge of the nucleus. The closer to the nucleus an elect...
by Rhea Shah 2F
Sun Oct 20, 2019 4:07 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Short Hand
Replies: 11
Views: 93

Re: Short Hand

Because the noble gases have their outer shell completely full, they are used in shorthand electron configurations. The noble gas of the period above that of the electron in focus is written in brackets, and then the valence electrons are written in after the brackets. This makes electron configurat...
by Rhea Shah 2F
Sun Oct 20, 2019 4:03 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Paired Electrons
Replies: 5
Views: 54

Re: Paired Electrons

Electrons are paired when they occupy the same orbital and have opposite spin. Electrons with parallel spins tend to avoid each other slightly, which lowers the energy of the electrons. Thus, paired electrons should have opposite spin to maximize the energy of the electrons.
by Rhea Shah 2F
Sun Oct 20, 2019 3:55 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Hund's rule and Pauli Exclusion Principle
Replies: 14
Views: 133

Re: Hund's rule and Pauli Exclusion Principle

Hund's rule and the Pauli Exclusion principle combine to form the building up principle. Hund's rule states that electron with parallel sping must be added to each available orbital in the subshell before pairing the electrons together. The Pauli Exclusion principle states that each orbital may only...
by Rhea Shah 2F
Sun Oct 20, 2019 3:52 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Opposite spin
Replies: 2
Views: 26

Re: Opposite spin

An electron can only have one of two spins, denoted by the spin magnetic quantum number, which can have a value of either +1/2 or -1/2. When writing the symbols of an electron configuration, the two spins are represented by either an up or down arrow. The two electrons in each orbital must have oppo...
by Rhea Shah 2F
Sat Oct 12, 2019 5:21 pm
Forum: DeBroglie Equation
Topic: Applying the DeBroglie Equation
Replies: 6
Views: 53

Re: Applying the DeBroglie Equation

The DeBroglie equation can be used on any particle with momentum, and is used to determine the wavelength of the particles movement. Since momentum is calculated by multiplying mass by velocity, the equation cannot be used for light particles as light does not have mass and thus does not have moment...
by Rhea Shah 2F
Sat Oct 12, 2019 5:15 pm
Forum: DeBroglie Equation
Topic: Momentum
Replies: 4
Views: 53

Re: Momentum

Momentum is involved in order to specify that the DeBroglie's equation is applicable only to particles with momentum. This specification is needed to make clear that the equation is not applicable to light particles as light does not have mass and therefore does not have momentum. Despite the almost...
by Rhea Shah 2F
Sat Oct 12, 2019 5:09 pm
Forum: Properties of Electrons
Topic: Energy of Electron
Replies: 10
Views: 148

Re: Energy of Electron

When he says this, he means that the electron can occupy only specific levels of energy (n=1,2,3,4...). The electron can never be in between such levels of energy, but rather, must occupy a discrete quantum level of energy. When an electron loses energy, it drops to a lower quantum level and the los...
by Rhea Shah 2F
Sat Oct 12, 2019 5:06 pm
Forum: Photoelectric Effect
Topic: Quanta and Photons
Replies: 3
Views: 66

Re: Quanta and Photons

Photons are packets of energy of which light is made up of. Quanta are the discrete energy levels that an electron can be at. When a high energy electron loses energy, it drops to a lower quantum level and the rest of the energy is given off as a photon.
by Rhea Shah 2F
Sat Oct 12, 2019 4:56 pm
Forum: Photoelectric Effect
Topic: Photons and electrons
Replies: 5
Views: 69

Re: Photons and electrons

I believe that each photon with enough energy removes one electron, as it was mentioned in lecture that doubling the amount of photons doubles the amount of electrons that are removed. The energy of each photon is the amount necessary to remove the electron plus any excess energy.
by Rhea Shah 2F
Sat Oct 05, 2019 4:59 pm
Forum: Significant Figures
Topic: Sig Fig Addition and Subtraction
Replies: 5
Views: 104

Re: Sig Fig Addition and Subtraction

What I was taught was that for addition and subtraction, you keep the same amount of decimal points as the number with the lowest amount, even if this means the sum/difference doesn't have the same amount of sig figs as the one with the fewest. For multiplication and division, the product/quotient s...
by Rhea Shah 2F
Sat Oct 05, 2019 4:55 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Mole help [ENDORSED]
Replies: 8
Views: 118

Re: Mole help [ENDORSED]

A mole is a unit of measurement that tells you how much of that element is needed to have 6.02 x 10^23 atoms of that element. The molar mass of each element that is listed on the periodic table is the amount in grams of that element needed to obtain that certain amount of atoms.
by Rhea Shah 2F
Sat Oct 05, 2019 4:52 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Accuracy v Precision
Replies: 11
Views: 149

Re: Accuracy v Precision

Accuracy measures the validity of your measurement, or how close you were to the actual values to be obtained. Precision on the other hand measures the replicability of your results, or how many times you got the same result. If your method of experimenting stays the same throughout multiple trials,...
by Rhea Shah 2F
Sat Oct 05, 2019 4:49 pm
Forum: Limiting Reactant Calculations
Topic: Percent or theoretical yield
Replies: 14
Views: 270

Re: Percent or theoretical yield

The theoretical yield is often in grams, and is calculated using the ratio of moles of the limiting reactant to the moles of the product. The percent yield, on the other hand, is given as a percentage and illustrates how much of the theoretical yield was actually produced. To calculate percent yield...
by Rhea Shah 2F
Sat Oct 05, 2019 4:43 pm
Forum: Balancing Chemical Reactions
Topic: adding a product
Replies: 6
Views: 65

Re: adding a product

The purpose of balancing chemical reactions is to ensure the conservation of mass, meaning atoms are not created or destroyed during a chemical reaction. Thus, you may only add stoichiometric coefficients to the front of each molecule in order to change the ratio of moles of each molecule. You canno...

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