Search found 104 matches

by Hannah Pham
Sun Mar 15, 2020 1:58 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Nernst K vs Q
Replies: 5
Views: 123

Re: Nernst K vs Q

You use K when the reaction is at equilibrium and Q if it is not.
by Hannah Pham
Sun Mar 15, 2020 1:57 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: spontaneity
Replies: 4
Views: 113

Re: spontaneity

You determine the value of delta G, and if it is negative, then it is spontaneous
by Hannah Pham
Sun Mar 15, 2020 1:55 pm
Forum: Calculating Work of Expansion
Topic: reversible expansion
Replies: 4
Views: 91

Re: reversible expansion

It represents work done by expansion
by Hannah Pham
Sun Mar 08, 2020 9:13 pm
Forum: Zero Order Reactions
Topic: Zero Order Rxn
Replies: 7
Views: 341

Re: Zero Order Rxn

Yes, zero order reactions do not need any other factors, only the rate constant.
by Hannah Pham
Sun Mar 08, 2020 9:12 pm
Forum: General Rate Laws
Topic: Rate limiting step
Replies: 12
Views: 127

Re: Rate limiting step

The rate limiting step is the slowest step of a chemical reaction that determines the rate at which the overall reaction proceeds.
by Hannah Pham
Sun Mar 08, 2020 9:10 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: pre-exponential factor
Replies: 3
Views: 42

Re: pre-exponential factor

A is the frequency of collisions in the correct orientation.
by Hannah Pham
Sun Mar 08, 2020 9:08 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Where do we find the values for A?
Replies: 5
Views: 124

Re: Where do we find the values for A?

A is the frequency of collisions. You can calculate A using the Arrhenius equation given the other variables, including temperature, activation energy, and equilibrium constant.
by Hannah Pham
Sun Mar 08, 2020 9:04 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Exothermic vs. Endothermic
Replies: 14
Views: 155

Re: Exothermic vs. Endothermic

It is an exothermic reaction when the activation energy of the reactants are higher than the products. If the activation energy of the products is higher than the reactants, then it is an endothermic reaction.
by Hannah Pham
Sun Mar 08, 2020 9:02 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Molecularity
Replies: 12
Views: 136

Re: Molecularity

Molecularity is the number of molecules or ions that participate in the rate determining step.
by Hannah Pham
Sat Feb 29, 2020 10:44 pm
Forum: Balancing Redox Reactions
Topic: Reducing/Oxidizing Agents
Replies: 13
Views: 104

Re: Reducing/Oxidizing Agents

Oxidizing agents are the ones that oxidize, so the remove electrons, while reducing agents are the ones doing the reducing, so they provide the electrons.
by Hannah Pham
Sat Feb 29, 2020 10:41 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: platinum
Replies: 5
Views: 54

Re: platinum

Yes, you use platinum if no metals are given as your conductor.
by Hannah Pham
Sat Feb 29, 2020 10:40 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Anode vs Cathode
Replies: 5
Views: 59

Re: Anode vs Cathode

The anode is the one being oxidized, which means it is losing electrons, while the cathode is being reduced, which means it is gaining electrons.
by Hannah Pham
Sat Feb 29, 2020 10:38 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: No Salt Bridge
Replies: 7
Views: 103

Re: No Salt Bridge

The anode is losing electrons, making it gain a more positive charge, while the cathode is gaining electrons making it have a more negative charge.
by Hannah Pham
Sat Feb 29, 2020 10:36 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Salt bridges
Replies: 11
Views: 119

Re: Salt bridges

The purpose of a salt bridge is to balance the charges between the half cells. The electrons flow from the anode to the cathode.
by Hannah Pham
Sun Feb 23, 2020 2:43 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Anode vs Cathode
Replies: 6
Views: 69

Re: Anode vs Cathode

The cathode is where the species are reduced and anode is where the species are oxidized.
by Hannah Pham
Sun Feb 23, 2020 2:40 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: n in -nFE
Replies: 12
Views: 120

Re: n in -nFE

n is the number of moles of electrons in a balanced half reaction.
by Hannah Pham
Sun Feb 23, 2020 2:38 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: positive E naught
Replies: 2
Views: 19

Re: positive E naught

When E is positive, then delta G is negative, which makes the reaction spontaneous and favorable.
by Hannah Pham
Sun Feb 23, 2020 2:36 pm
Forum: Balancing Redox Reactions
Topic: Oxidizing/Reducing Agents
Replies: 11
Views: 180

Re: Oxidizing/Reducing Agents

Oxidizing agents are the ones that oxidize, so the remove electrons, while reducing agents are the ones doing the reducing, so they provide the electrons.
by Hannah Pham
Sun Feb 23, 2020 2:34 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: salt bridge
Replies: 5
Views: 31

Re: salt bridge

The purpose of a salt bridge is to balance the charges between the half cells. The electrons flow from the anode to the cathode.
by Hannah Pham
Sun Feb 16, 2020 8:19 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Spontaneous
Replies: 13
Views: 154

Re: Spontaneous

A spontaneous reaction has a delta G value that is negative (G<0)
by Hannah Pham
Sun Feb 16, 2020 8:14 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K
Replies: 12
Views: 155

Re: K

To calculate K, use gases and aqueous solutions but not solids or liquids.
by Hannah Pham
Sun Feb 16, 2020 8:13 pm
Forum: Balancing Redox Reactions
Topic: Oxygen and Hydrogen
Replies: 4
Views: 49

Re: Oxygen and Hydrogen

Hydrogen has an oxidation number of +1 when combined with nonmetals but has an oxidation number of -1 when combined with metals. Oxygen can have an oxidation number of -2, -1, or 0.
by Hannah Pham
Sun Feb 16, 2020 8:03 pm
Forum: Balancing Redox Reactions
Topic: Reduction vs. oxidation
Replies: 29
Views: 325

Re: Reduction vs. oxidation

Oxidation is the loss of electrons and reduction is the gain of electrons. You can determine what is being reduced or oxidized is by the change in oxidation numbers of reactants and products.
by Hannah Pham
Sun Feb 16, 2020 8:00 pm
Forum: Van't Hoff Equation
Topic: Van't Hoff Equation
Replies: 3
Views: 30

Re: Van't Hoff Equation

The Van't Hoff Equation can be used to calculate K at different temperatures if enthalpy of reaction is known. It relates the change in equilibrium constant of a chemical reaction to the change in temperature.
by Hannah Pham
Sat Feb 08, 2020 12:14 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Addition of a solid product/reactant
Replies: 3
Views: 76

Re: Addition of a solid product/reactant

Equilibrium will not shift because it only take into account gases and aqueous solution not liquids or solids.
by Hannah Pham
Sat Feb 08, 2020 12:12 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Delta H and qp
Replies: 8
Views: 55

Re: Delta H and qp

ΔH = qp when pressure is constant.
by Hannah Pham
Sat Feb 08, 2020 12:10 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard enthalpies of formation
Replies: 5
Views: 39

Re: Standard enthalpies of formation

Yes, balance the equation and the multiply the standard enthalpy of formation of products and reactants by their stoichiometric coefficients.
by Hannah Pham
Sat Feb 08, 2020 12:08 pm
Forum: Calculating Work of Expansion
Topic: Units for -PV
Replies: 5
Views: 51

Re: Units for -PV

For pressure use atm, then for the overall answer you would get L atm and convert those units to joules using 1 L atm = 101.325 J
by Hannah Pham
Sat Feb 08, 2020 12:06 pm
Forum: Calculating Work of Expansion
Topic: Constant Volume and Pressure Values
Replies: 8
Views: 106

Re: Constant Volume and Pressure Values

I think it would be good for you to remember them, especially monoatomic ones.
by Hannah Pham
Sun Feb 02, 2020 7:03 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Closed vs isolated systems
Replies: 24
Views: 205

Re: Closed vs isolated systems

In a closed system, the matter within the system is constant but energy can be transferred from the system to surroundings and vice versa. In an isolated system, neither matter nor energy between system and surroundings are allowed.
by Hannah Pham
Sun Feb 02, 2020 7:00 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: extensive property
Replies: 12
Views: 150

Re: extensive property

An extensive property is a property that changes when the amount of matter changes. Examples include mass, volume, and internal energy.
by Hannah Pham
Sun Feb 02, 2020 6:55 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Delta U = Q
Replies: 8
Views: 43

Re: Delta U = Q

When W = 0 there is constant volume, in which there is no expansion or compression because that is when work is done.
by Hannah Pham
Sun Feb 02, 2020 6:50 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Test 1 #6
Replies: 6
Views: 68

Re: Test 1 #6

HF is a weak acid and not a strong acid because it does not completely dissociate in water. The ions it forms during dissociation are too strongly bound to each other for it to be a strong acid.
by Hannah Pham
Sun Feb 02, 2020 6:44 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Constant Volume and Pressure
Replies: 7
Views: 47

Re: Constant Volume and Pressure

Constant volume and constant pressure means that the volume or pressure does not change during a reaction.
by Hannah Pham
Sun Jan 26, 2020 10:32 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Negative Square Root solving an ICE box
Replies: 13
Views: 103

Re: Negative Square Root solving an ICE box

You might have made a mistake because you should not have a negative number inside the square root. However, the overall answer when solving the quadratic formula can be positive and negative.
by Hannah Pham
Sun Jan 26, 2020 10:26 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hess's Law
Replies: 9
Views: 138

Re: Hess's Law

Hess's Law states that regardless of the intermediate steps taken in a reaction, the total enthalpy change for the reaction is the sum of each individual changes.
by Hannah Pham
Sun Jan 26, 2020 10:25 pm
Forum: Phase Changes & Related Calculations
Topic: Hess's Law
Replies: 8
Views: 66

Re: Hess's Law

Hess's Law states that regardless of the intermediate steps taken in a reaction, the total enthalpy change for the reaction is the sum of each individual changes.
by Hannah Pham
Sun Jan 26, 2020 10:20 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Exothermic reaction
Replies: 18
Views: 261

Re: Exothermic reaction

If the reaction is exothermic, increase in temperature would cause the reaction to shift left and decrease in temperature would cause the reaction to shift right
by Hannah Pham
Sun Jan 26, 2020 10:15 pm
Forum: Phase Changes & Related Calculations
Topic: Enthalpy
Replies: 5
Views: 70

Re: Enthalpy

Enthalpy is a state function because it only depends on initial and final values in the reaction. The path taken to get from the initial to final value does not matter.
by Hannah Pham
Sun Jan 26, 2020 10:13 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: endothermic
Replies: 8
Views: 51

Re: endothermic

If reaction is endothermic and there is an increase in temperature, the forward reaction (products) is favored and the equilibrium constant increases.
by Hannah Pham
Sun Jan 26, 2020 10:11 pm
Forum: Ideal Gases
Topic: Kc vs Kp
Replies: 43
Views: 567

Re: Kc vs Kp

If the reaction consists of all gases then you would use Kp. Kc can be used for gases as well if the gases are given in concentration rather than pressure.
by Hannah Pham
Sun Jan 26, 2020 10:05 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Finding Ka from pH
Replies: 5
Views: 60

Re: Finding Ka from pH

If you're given pH or pOH then use [H3O+] = 10^-pH and [OH-] = 10^-pOH to determine concentration, and plug the concentrations into Ka/Kb formula to determine Ka/Kb value.
by Hannah Pham
Sun Jan 26, 2020 10:00 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: pH
Replies: 7
Views: 87

Re: pH

You could convert pKa to Ka, then use Ka = 10^(-pKa). Use the Ka to find [H3O+]. Determine pH by this equation: pH = -log [H3O+].
by Hannah Pham
Sun Jan 26, 2020 9:55 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ICE BOX
Replies: 27
Views: 265

Re: ICE BOX

You would X is too small when K < 10^3
by Hannah Pham
Fri Jan 10, 2020 4:09 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K expression involving solids/liquids
Replies: 7
Views: 56

Re: K expression involving solids/liquids

To determine the equilibrium constant, only gases and aqueous solutions are used. Liquids and solids are not used because pure substances do not change in a reaction.
by Hannah Pham
Fri Jan 10, 2020 4:06 pm
Forum: Ideal Gases
Topic: R in PV=nRT
Replies: 34
Views: 735

Re: R in PV=nRT

R is the Ideal Gas Constant which has the value of 8.314J/molK.
by Hannah Pham
Fri Jan 10, 2020 4:04 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Pressure and Volume
Replies: 8
Views: 53

Re: Pressure and Volume

Changes in pressure and volume do not affect value of the equilibrium constant.
by Hannah Pham
Fri Jan 10, 2020 4:02 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: using Kp vs Kc
Replies: 13
Views: 118

Re: using Kp vs Kc

Kp is for partial pressure, so when your products and reactants are in the gas phase. Kc is for concentration. However, for gases, you can use either Kc or Kp and just convert using the Ideal Gas Law.
by Hannah Pham
Fri Jan 10, 2020 3:47 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: K vs Q
Replies: 9
Views: 161

Re: K vs Q

Q measures the relative amounts of products and reactant present during a reaction at a particular point in time. Q is compared to K, the equilibrium constant, to determine which direction the reaction proceeds. If Q>K, then the reverse reaction is favored and if Q<K, then the forward reaction is fa...
by Hannah Pham
Sun Dec 08, 2019 5:01 pm
Forum: Resonance Structures
Topic: Molecules with resonance
Replies: 4
Views: 221

Re: Molecules with resonance

Acids are stronger when there is resonance because the electrons are delocalized, in which the charges would be spread out more.
by Hannah Pham
Sun Dec 08, 2019 4:58 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate
Replies: 3
Views: 137

Re: Polydentate

The ligand is polydentate if there are more than one lone pairs that the atom can donate to the transition metal it forms a coordination compound with.
by Hannah Pham
Sun Dec 08, 2019 4:57 pm
Forum: Lewis Acids & Bases
Topic: Mg(OH)2 Considered strong or weak base?
Replies: 5
Views: 165

Re: Mg(OH)2 Considered strong or weak base?

Mg(OH)2 is a strong base because it is one of the Group 1 and 2 oxide and hydroxides, where those are strong bases.
by Hannah Pham
Sun Dec 08, 2019 4:55 pm
Forum: Properties of Light
Topic: Light acting like a wave
Replies: 4
Views: 163

Re: Light acting like a wave

Light acts like a wave when it forms diffraction patterns, in which there is interference in the waves. This was proven in the experiment where light passed through the opening of two slits and forms interference patterns on a screen. The bands were darker where it was between the spot between the s...
by Hannah Pham
Sun Dec 08, 2019 4:48 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: Hydrogen Bonding
Replies: 2
Views: 116

Re: Hydrogen Bonding

SO3 can form hydrogen bonds in water because it contains oxygen atoms, which can form a bond with hydrogen atom from the water molecule due to partial charges on the atoms.
by Hannah Pham
Sat Nov 30, 2019 11:40 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate
Replies: 3
Views: 22

Re: Polydentate

A polydentate ligand has multiple lone pair donating sites that are bonded to a central atom.
by Hannah Pham
Sat Nov 30, 2019 11:37 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Shapes
Replies: 3
Views: 46

Re: Shapes

Tetrahedral shape is formed when there are four electron densities, which are four bonds with no lone pairs and square planar is formed when there are six electron densities, consisting of four bonds and two lone pairs.
by Hannah Pham
Sat Nov 30, 2019 11:31 pm
Forum: Identifying Acidic & Basic Salts
Topic: salt and water formation
Replies: 5
Views: 59

Re: salt and water formation

When acid and base solutions react, they produce water and a neutral ionic compound, salt, which is composed of a cation (from the base) and and anion (from the acid).
by Hannah Pham
Sat Nov 30, 2019 11:21 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligands
Replies: 1
Views: 29

Re: Ligands

A ligand is an atom or molecule that binds to a metal ion through coordinate bonding.
by Hannah Pham
Sat Nov 30, 2019 11:20 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate = more than one lone pair?
Replies: 4
Views: 49

Re: Polydentate = more than one lone pair?

A polydentate ligand has more than two lone pair donating sites that are used to bond to a central atom.
by Hannah Pham
Sun Nov 24, 2019 2:50 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent vs linear
Replies: 56
Views: 1216

Re: Bent vs linear

The bent shape has lone pair on the central atom while the linear shape typically does not have any lone pairs except for the exception of the molecule with 5 electron densities where there are 2 bonds and 3 lone pairs and the molecule with 6 electron densities with 2 bonds and 4 electron densities.
by Hannah Pham
Sun Nov 24, 2019 2:46 am
Forum: Sigma & Pi Bonds
Topic: Rotation
Replies: 3
Views: 43

Re: Rotation

Sigma bonds have their electron density along the bond axis, while pi bonds have their electron density above and below the bond axis. Therefore, the pi bonds cannot rotate like the sigma bonds because rotating would break the pi bond.
by Hannah Pham
Sun Nov 24, 2019 2:44 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: AXE formula
Replies: 32
Views: 5177

Re: AXE formula

It is possible to determine the molecular shape from AXE formula. The formula corresponds to the number of electron densities, including the lone pairs and bonds, which is then used to determine shape of the molecule.
by Hannah Pham
Sun Nov 24, 2019 2:42 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Oxidation Number
Replies: 3
Views: 41

Re: Oxidation Number

The oxidation number is the number of electrons that an atom gains or loses in order to form a chemical bond with another atom. It shows the total number of electrons that have been removed from an element (positive oxidation state) or added to an element (negative oxidation state) to get to its pre...
by Hannah Pham
Sun Nov 24, 2019 2:40 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: dipole-dipole in a solid phase vs gas phase
Replies: 15
Views: 284

Re: dipole-dipole in a solid phase vs gas phase

Dipole-dipole in the solid phase is stronger because there are stronger attractions between molecules than in the gas phase.
by Hannah Pham
Sun Nov 17, 2019 9:58 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pairs on VSEPR Model
Replies: 2
Views: 50

Lone Pairs on VSEPR Model

How do you know if a lone pair lies on the axial or equatorial position?
by Hannah Pham
Sun Nov 17, 2019 9:54 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: intermolecular forces
Replies: 2
Views: 21

Re: intermolecular forces

Intermolecular forces are usually temporary such as instantaneous dipole-induced-dipole forces or London dispersion forces, which are forces caused by movements of the electrons in interacting molecules. Dipole-dipole forces are electrostatic interactions of permanent dipoles in molecules.
by Hannah Pham
Sun Nov 17, 2019 9:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Model
Replies: 3
Views: 55

Re: VSEPR Model

I think we will have to memorize the molecular shapes and bonds angles based off the Lewis structures.
by Hannah Pham
Sun Nov 17, 2019 9:44 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: covalent vs hydrogen bond?
Replies: 2
Views: 26

Re: covalent vs hydrogen bond?

Covalent bonds are formed when atoms within a molecule share electrons. Hydrogen bonding is when a partial positive charge of hydrogen atom of one molecule is attracted to another electronegative molecule (O, N, F). Intramolecular bonds are stronger than intermolecular forces, in which hydrogen bond...
by Hannah Pham
Sun Nov 17, 2019 9:36 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 4
Views: 54

Bond Angles

How do you determine bond angles based off the molecular shape?
by Hannah Pham
Sun Nov 10, 2019 10:54 pm
Forum: Sigma & Pi Bonds
Topic: Occurance of Hybridization
Replies: 1
Views: 41

Re: Occurance of Hybridization

To determine hybridization, draw lewis dot structure and determine the steric number (the number of atoms bonded to a central atom plus the number of lone pairs attached to it) which will tell you the number of atomic orbitals needed to create a hybrid.
by Hannah Pham
Sun Nov 10, 2019 10:49 pm
Forum: Bond Lengths & Energies
Topic: Bond lengths and strength
Replies: 4
Views: 41

Re: Bond lengths and strength

Double bonds are stronger than single bonds, characterized by the sharing of four or six electrons between atoms. Double bonds are composed of sigma bonds between hybridized orbitals, and pi bonds between unhybridized p orbitals. Double bonds give additional stability to compounds.
by Hannah Pham
Sun Nov 10, 2019 10:46 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Oxidation Number
Replies: 6
Views: 82

Re: Oxidation Number

The oxidation number is the number of electrons that an atom gains or loses in order to form a chemical bond with another atom. It shows the total number of electrons that have been removed from an element (positive oxidation state) or added to an element (negative oxidation state) to get to its pre...
by Hannah Pham
Sun Nov 10, 2019 10:34 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: polarizability/polar power and bonds
Replies: 2
Views: 119

Re: polarizability/polar power and bonds

Polarizability results in distortion of the atom. If the degree of polarization is small, an ionic bond is formed, and if the degree of polarization is large, a covalent bond results. The ability of an atom is known as polar power, which is usually the cation, while the tendency of the anion to beco...
by Hannah Pham
Sun Nov 10, 2019 10:23 pm
Forum: Ionic & Covalent Bonds
Topic: Drawing hydrogen bonds between compounds?
Replies: 1
Views: 43

Re: Drawing hydrogen bonds between compounds?

Yes, that would be typically how you would draw hydrogen bonds. And just make sure that when you draw a hydrogen bond, it must be between a hydrogen atom with a partial positive charge of one molecule and a partial negative atom (either O, N, F) of another molecule.
by Hannah Pham
Sat Nov 02, 2019 10:27 pm
Forum: Ionic & Covalent Bonds
Topic: covalent character
Replies: 3
Views: 45

Re: covalent character

By having covalent character, there is partial sharing of electrons between atoms that have an ionic bond. The degree of ionic versus covalent character of a bond is determined by the difference in electronegativity between the atoms.
by Hannah Pham
Sat Nov 02, 2019 10:14 pm
Forum: Coordinate Covalent Bonds
Topic: Atom Sharing
Replies: 5
Views: 109

Re: Atom Sharing

I think the only difference between them is that coordinate covalent bonds share a pair of electrons and a covalent bonds shares one electron.
by Hannah Pham
Sat Nov 02, 2019 10:02 pm
Forum: Lewis Structures
Topic: Expanded Octet
Replies: 3
Views: 44

Expanded Octet

How do you know when a molecule has an expanded octet? Would you have to just guess and check by determining the formal changes in which it would have to be 0? For example SO3 and SO4. Are there certain elements that tend to have expanded octet?
by Hannah Pham
Sat Nov 02, 2019 9:50 pm
Forum: Limiting Reactant Calculations
Topic: Test 1 Question
Replies: 5
Views: 251

Re: Test 1 Question

You would convert the moles of water formed to moles of glucose using the balanced equation, then convert the amount you found to grams of glucose. After, you would subtract that from the grams of glucose initially present. To determine how many moles of O2 initially present, use the moles of H20 pr...
by Hannah Pham
Sat Nov 02, 2019 9:40 pm
Forum: Empirical & Molecular Formulas
Topic: Formula Units
Replies: 2
Views: 154

Re: Formula Units

To find molecules or formula units, you would use Avogadro's number to convert from moles.
by Hannah Pham
Sun Oct 27, 2019 9:02 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic v. Covalent
Replies: 7
Views: 74

Re: Ionic v. Covalent

Ionic bonds are formed when atoms lose or gain electrons and covalent bonds are formed when atoms share electrons. Ionic bonds are stronger than covalent bonds but in water, covalent bonds are stronger than ionic bonds, in which ionic bonds dissociate when in water.
by Hannah Pham
Sun Oct 27, 2019 9:00 pm
Forum: Bond Lengths & Energies
Topic: Lattice Energy
Replies: 9
Views: 75

Re: Lattice Energy

Lattice energy is the energy given off when oppositely charged ions in the gas phase come together to form a solid.
by Hannah Pham
Sun Oct 27, 2019 8:57 pm
Forum: Electronegativity
Topic: Polarity
Replies: 5
Views: 66

Re: Polarity

The polarity of a bond is determined by the electronegativities of the bonded atoms, in which electronegativity is the ability of an atom in a molecule to attract electrons to itself.
by Hannah Pham
Sun Oct 27, 2019 8:55 pm
Forum: Resonance Structures
Topic: Resonance Structures
Replies: 4
Views: 56

Resonance Structures

How do we know how many resonance structures a molecule has?
by Hannah Pham
Sun Oct 27, 2019 8:45 pm
Forum: Trends in The Periodic Table
Topic: Electronegativity vs. Electron affinity
Replies: 8
Views: 137

Re: Electronegativity vs. Electron affinity

The difference is that electronegativity is the ability of an atom to attract electrons towards itself while electron affinity is the amount of energy released when an atom gains an electron.
by Hannah Pham
Sun Oct 27, 2019 8:41 pm
Forum: Ionic & Covalent Bonds
Topic: What is the difference between an anion and cation?
Replies: 7
Views: 118

Re: What is the difference between an anion and cation?

An anion is an atom that accepts electrons making it have a negative charge and a cation is an atom that donates electrons making it positively charged. Usually cations are metals and nonmetals are anions. An example of a cation is Na+ and an example of an anion is Cl-.
by Hannah Pham
Sun Oct 20, 2019 6:23 pm
Forum: Quantum Numbers and The H-Atom
Topic: Quantum Numbers
Replies: 5
Views: 76

Re: Quantum Numbers

The magnetic quantum number labels the different orientation of the orbitals in a subshell.
by Hannah Pham
Sun Oct 20, 2019 6:14 pm
Forum: Quantum Numbers and The H-Atom
Topic: Magnetic Quantum Number ml
Replies: 5
Views: 52

Re: Magnetic Quantum Number ml

An example would be how orbitals in p subshell could have orientation of px, py, or pz
by Hannah Pham
Sun Oct 20, 2019 6:12 pm
Forum: Quantum Numbers and The H-Atom
Topic: Magnetic Quantum Number ml
Replies: 5
Views: 52

Re: Magnetic Quantum Number ml

ml describes the different orbitals of a subshell, so the orientation.
by Hannah Pham
Sun Oct 20, 2019 6:08 pm
Forum: *Shrodinger Equation
Topic: Schrodinger’s Wave Function
Replies: 3
Views: 62

Re: Schrodinger’s Wave Function

In Schrodinger's Wave Function, the probability of finding an electron within the region of the atom is determined by squaring the wave function, ψ2, in which the wave function is a set of all the amplitudes.
by Hannah Pham
Sun Oct 20, 2019 6:00 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Stern and Gerlach
Replies: 3
Views: 57

Re: Stern and Gerlach

Spin up and spin down refers to the directions in which the electrons are moving. One electron could be spin up (positive spin) and the other would be spin down (negative spin).
by Hannah Pham
Sun Oct 20, 2019 5:47 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 3d vs 4s
Replies: 2
Views: 36

Re: 3d vs 4s

Electrons are removed from 4s first.
by Hannah Pham
Sun Oct 13, 2019 10:06 pm
Forum: Properties of Electrons
Topic: Photon
Replies: 5
Views: 38

Re: Photon

A photon is a particle of visible light.
by Hannah Pham
Sun Oct 13, 2019 10:02 pm
Forum: DeBroglie Equation
Topic: Detectable wavelike properties
Replies: 1
Views: 36

Detectable wavelike properties

Using the De Broglie equation, within what range would there be detectable wavelike properties?
by Hannah Pham
Sun Oct 13, 2019 9:58 pm
Forum: Properties of Electrons
Topic: Diffraction
Replies: 2
Views: 23

Re: Diffraction

Constructive interference is when the waves that meet are in the same direction, which could result in higher peaks. Destructive interference occurs when displacement of the waves that meet are in opposite directions; this could result in lower peaks.
by Hannah Pham
Sun Oct 13, 2019 9:45 pm
Forum: Limiting Reactant Calculations
Topic: Tricky Limiting Reagent Question
Replies: 3
Views: 188

Re: Tricky Limiting Reagent Question

You just need to convert the given amount of product to the amount of reactant of CO2 and determine whether the given amount of CO2 in the problem was more or less than what was used up in the reaction. If it was in excess, then the other reactant would have been the limiting reactant. If CO2 was th...
by Hannah Pham
Sun Oct 13, 2019 9:25 pm
Forum: *Black Body Radiation
Topic: Unit K in Wien's Law
Replies: 2
Views: 54

Re: Unit K in Wien's Law

K is the temperature in Kelvin and m refers to the wavelength.
by Hannah Pham
Sun Oct 06, 2019 5:25 pm
Forum: Significant Figures
Topic: Periodic table AMU values
Replies: 2
Views: 39

Re: Periodic table AMU values

I think it would be better to use the number of sig figs that are given in the problem rather than the one given by the periodic table.
by Hannah Pham
Sun Oct 06, 2019 5:20 pm
Forum: Limiting Reactant Calculations
Topic: How to determine limiting reactants
Replies: 3
Views: 78

Re: How to determine limiting reactants

Do you know which method is better or faster?

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