## Search found 80 matches

Sat Mar 14, 2020 4:35 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: determining a catalyst
Replies: 5
Views: 51

### Re: determining a catalyst

It is also important to distinguish between a catalyst and an intermediate in that one (the catalyst) is consumed by a step but regenerated by a later step; the other (intermediate) is created by a step but consumed by a later step.
Sat Mar 14, 2020 4:32 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Calculating K
Replies: 4
Views: 108

### Calculating K

When given values for standard enthalpy of reaction and value for K at one temperature, how do you find the K at another temperature (assuming that the standard enthalpy and entropy of the reaction stay constant over this temperature change)
Sat Mar 14, 2020 4:28 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Electrode Mass
Replies: 10
Views: 238

### Electrode Mass

Can someone explain the effect of changing the mass of the electrode on the cell potential?
Sat Mar 14, 2020 4:24 pm
Forum: General Rate Laws
Topic: Initial Rate
Replies: 5
Views: 103

### Initial Rate

When finding the initial rate or initial concentrations, is it possible that there'll be a case where you won't have constant initial concentrations to figure out each of the order of reactants? I think I came across this scenario once, so how would you approach the problem? This applies to problems...
Sat Mar 14, 2020 4:14 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Arrhenius Equation "A"
Replies: 3
Views: 26

### Re: Arrhenius Equation "A"

Yeah, A in the equation is the frequency factor or pre-exponential factor, which also includes # of collisions with the correct orientation!
Thu Mar 05, 2020 8:01 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: max work and cell potential
Replies: 3
Views: 77

### Re: max work and cell potential

The maximum work is done under conditions of constant T &P so Gibbs free energy, which is the amount of energy that is free to do work, is the same as maximum work. The equation for Gibbs free energy=-nFE so we see the same equation for max work.
Thu Mar 05, 2020 7:52 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Temperature
Replies: 2
Views: 55

### Re: Temperature

temperature and rate constant have a directly proportional relationship. When t2>T1, the right-side is +, so ln of the ratio of the two constants is +, which means that k2>K1. This makes sense conceptually too because increasing temperature increases the speed of molecules which increases the chance...
Thu Mar 05, 2020 7:48 pm
Forum: General Science Questions
Topic: Reducing Math Errors
Replies: 7
Views: 181

### Re: Reducing Math Errors

before you write down ur values, just doublecheck the numbers that appear and make sure you're writing the same number and right decimal points. Also, despite the sig figs needed for the end value, it's best not to use this to write down numbers during the actual calculation process.
Thu Mar 05, 2020 7:45 pm
Forum: Balancing Redox Reactions
Topic: Values of Andode and Cathode
Replies: 8
Views: 135

### Re: Values

value of what? If you are referring to the standard reduction potential of the anode and cathode, then yes.
Thu Mar 05, 2020 7:44 pm
Forum: Balancing Redox Reactions
Topic: Strength of Reducing/Oxidizing Agents
Replies: 4
Views: 83

### Re: Strength of Reducing/Oxidizing Agents

Adding on to that, the higher to the top of the electrochemical series, the more favorable the rxtn is for reduction. Conversely, the bottom of the list favors oxidation (giving away electron).
Sun Mar 01, 2020 2:03 pm
Forum: General Rate Laws
Topic: Integrated Rate Law
Replies: 5
Views: 68

### Integrated Rate Law

What is the significance of changing a differential rate law into an integrated rate law?
Sun Mar 01, 2020 2:00 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Salt Bridge
Replies: 10
Views: 71

### Re: Salt Bridge

The purpose of a salt bridge is to maintain a balance of charges, since the electrons are moving from one half cell to another. This allows for the continuation of electron flow.
Sun Mar 01, 2020 1:55 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: cell diagrams: order of components in electrodes?
Replies: 3
Views: 65

### Re: cell diagrams: order of components in electrodes?

anode left; cathode right -separate anode and cathode with a salt bridge denoted by 2 lines - separate different states with a single line but if it's the same state but different species, denote it with a comma - solids are on the outside (solid metal electrode) and if no metal in the reaction, use...
Sun Mar 01, 2020 1:51 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Determining "n" (6L.1)
Replies: 1
Views: 44

### Re: Determining "n" (6L.1)

Since n is the number of electrons, you would use the half reactions to determine how many electrons were lost or gained (same #) and this is your value for n.
Sun Mar 01, 2020 1:47 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: C(gr) state
Replies: 4
Views: 44

### Re: C(gr) state

It means Carbon in the form of solid graphite.
Sat Feb 22, 2020 9:50 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Pt
Replies: 7
Views: 72

### Pt

In the cell diagrams, what does "Pt(s)" mean? And how does this change how we set up the diagram or chemical reaction equations?
Sat Feb 22, 2020 9:48 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: relationship between concentration and Ecell
Replies: 2
Views: 20

### Re: relationship between concentration and Ecell

Changing the concentration of the reactants or products would make Ecell either > or < E°cell, and we know from the Nernst Equation that the ratio of the concentration of products and reactants (Quotient value) is considered when calculating the value for cell potential (Ecell).
Sat Feb 22, 2020 9:45 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Relationship between Gibbs free energy and E
Replies: 2
Views: 38

### Re: Relationship between Gibbs free energy and E

Yes, there is that equation, but this equation can also be changed to include values for R constant, temperature, and the concentration of the products and reactants. Well, based on the equation, the spontaneity of the reaction would affect E since having a negative value for delta G (spontaneous) w...
Sat Feb 22, 2020 9:38 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: property of E
Replies: 6
Views: 65

### Re: property of E

When the chemical reaction is multiplied by a factor, delta G and delta°G is increased by that factor, but Ecell and E°cell stays the same. This is also because cell potential is independent of the cell size.
Sat Feb 22, 2020 9:36 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Cell Potential
Replies: 2
Views: 53

### Re: Cell Potential

When Ecell>E°cell, you are favoring product formation. AN increase in product concentration leads to an increase in delta G. Based on the equation, an increase in delta G would yield an increase in E cell so they are directly related! As for Ecell<E°cell, you are favoring reactant formation, which t...
Sun Feb 16, 2020 8:39 pm
Forum: Balancing Redox Reactions
Topic: Oxidation Number
Replies: 2
Views: 44

### Re: Oxidation Number

There are rules in determining the oxidation numbers and here are a few: 1)The oxidation number of a free element is always 0. 2)The oxidation number of a monatomic ion equals the charge of the ion. 3) There are some elements that already have a set oxidation number unless it is present in a compoun...
Sun Feb 16, 2020 8:35 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Irreversible isothermal expansion of gas
Replies: 4
Views: 82

### Re: Irreversible isothermal expansion of gas

Since delta S of the system is 3.84 Joules per Kelvins (from an isothermal, reversible expansion), and if we assume that delta S of the surroundings is also 0, the total delta S is 3.84 Joules per Kelvins as well. Both delta U and w is equal to 0, so the value of q is also 0, which accounts for the ...
Sun Feb 16, 2020 8:27 pm
Forum: Van't Hoff Equation
Topic: Variable Explanations
Replies: 3
Views: 43

### Re: Variable Explanations

There is also delta S (standard), however, we can assume this value is constant and just take in values of enthalpy and temperature
Sun Feb 16, 2020 8:24 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: S = kblnW explanation
Replies: 4
Views: 68

### Re: S = kblnW explanation

This equation is for residual or positional entropy where you take into consideration the degeneracy value to determine the entropy value (as opposed to the other equation that takes in values for heat and temperature)
Sun Feb 16, 2020 8:22 pm
Forum: Van't Hoff Equation
Topic: Equilibrium Constant
Replies: 4
Views: 80

### Equilibrium Constant

In the equation 0=standard delta G+RTlnQ, why is the value of Q the equilibrium constant of the reaction?
Sat Feb 08, 2020 10:51 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Delta U at Constant V/P
Replies: 4
Views: 63

### Re: Delta U at Constant V/P

Yes, at constant volume, delta U=qv and at constant pressure, delta U=qp+w (using qp=delta H, we can rewrite it as delta U=delta H-P*deltaV.
Sat Feb 08, 2020 10:47 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard enthalpies of formation
Replies: 5
Views: 40

### Re: Standard enthalpies of formation

Yes, you would make sure the reaction is balanced first so that you can multiply the standard enthalpies of formation of each product/reactants by the corresponding stoichiometric coefficient. Then proceed with the equation where you subtract the sum of these values (reactants) from that of products.
Fri Feb 07, 2020 8:13 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Standard Delata G Value
Replies: 2
Views: 44

### Standard Delata G Value

When calculating the standard delta G, we can use the standard enthalpy of formation and standard molar entropy values of the reactants and products. However, are these values given to us in the question/table or do we have to compute these values separately as well?
Fri Feb 07, 2020 8:09 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free Energy
Replies: 5
Views: 62

### Gibbs Free Energy

Is there an easier way to think about the relationship of G, H, S, and temperature in the Gibbs free energy equation and how increasing/decreasing one variable will result in a positive/negative value for delta G?
Fri Feb 07, 2020 8:07 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Larger S
Replies: 1
Views: 40

### Larger S

For question 4G.5, how would you calculate the entropy value for the cis molecule? I still don't quite understand how to draw this out and determine the degeneracy value...
Sat Feb 01, 2020 3:10 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Extensive/Intensive Property
Replies: 4
Views: 40

### Extensive/Intensive Property

Why is heat capacity an extensive property and specific heat capacity an intensive property? What does this mean?
Sat Feb 01, 2020 3:08 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat capacity
Replies: 2
Views: 26

### Re: Heat capacity

yes, I believe heat capacity can be negative and this would indicate that when a system loses energy, its temperature increases.
Sat Feb 01, 2020 3:04 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Energy of Systems
Replies: 4
Views: 56

### Energy of Systems

Lavelle mentioned that there were 3 ways of changing the energy of a system, but can someone explain a little bit more about each?
Sat Feb 01, 2020 3:00 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy of Rxn
Replies: 9
Views: 82

### Re: Enthalpy of Rxn

You would multiply 300kJ/mol by the 0.05 mol since we are trying to get rid of the mol unit. Keep in mind we are trying to find the enthalpy of the reaction which the units are in joules.
Sat Feb 01, 2020 2:57 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Degeneracy
Replies: 3
Views: 39

### Re: Degeneracy

The dog bones he had up there were representations of the various micro states that 2 atoms can be in. Degeneracy is the number of ways of achieving a given energy state, and for 2 particles, there are 4 micro states that can fulfill this (the 4 dog bones with different combos of A/B positioning).
Sun Jan 26, 2020 1:41 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat Capacity
Replies: 7
Views: 102

### Heat Capacity

What is the relationship between high/low heat capacity and overall transfer of energy?
Sun Jan 26, 2020 1:39 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: State Function
Replies: 1
Views: 17

### State Function

I still don't understand when it says that internal energy, volume, pressure, enthalpy, temp, density etc are state functions and the significance of this? Can someone explain it in the simplest terms with examples as well?
Sun Jan 26, 2020 1:33 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Ideal Gas QUestions
Replies: 8
Views: 81

### Re: Ideal Gas QUestions

yes, pressure and volume are inversely proportional (this is called Boyle's Law)
Sun Jan 26, 2020 1:31 am
Forum: Phase Changes & Related Calculations
Topic: Hess's Law
Replies: 3
Views: 41

### Re: Hess's Law

the two reactions can be "fused" together to yield the end reaction, where if the reactant for one reaction is the same as the product for the other reaction, they cancel each other out. Also, you can have the product of one reaction as the reactant for the second reaction to yield the fin...
Sat Jan 25, 2020 4:12 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Decreasing volume
Replies: 5
Views: 52

### Decreasing volume

why is it that decreasing volume (and conversely increasing pressure) and having more moles of gas on the reactant side, favors product formation? viceversa?
Sat Jan 25, 2020 4:08 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard enthalpy
Replies: 2
Views: 20

### Standard enthalpy

What is the relationship between standard reaction enthalpy and standard enthalpy of formation?
Sat Jan 25, 2020 4:05 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpy
Replies: 4
Views: 29

### Bond Enthalpy

What is bond enthalpy and why is it always a positive value?
Sat Jan 25, 2020 4:03 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Water Properties
Replies: 3
Views: 122

### Water Properties

In the textbook, it stated that water is amphiprotic but that this was different than being amphoteric. Can someone explain the difference between the two?
Sat Jan 25, 2020 3:59 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: work
Replies: 5
Views: 64

### Re: work

work=opposing force x distance moved and work(w) is usually reported in joule (J).
This equation reflects the definition of work, which is the process of achieving motion against an opposing force
Fri Jan 17, 2020 7:04 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Conjugate Acids/Bases
Replies: 2
Views: 105

### Conjugate Acids/Bases

What is a conjugate acid/base and what is its relationship to the acid/base in the same reaction?
Fri Jan 17, 2020 7:01 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Autoprotolysis
Replies: 1
Views: 100

### Autoprotolysis

Can someone explain more thoroughly the concept, autoprotolysis? I understand that its constant of water at 25 degrees celsius is 1x10^-14 (Kw), but how do we come to this value and what does it mean?
Fri Jan 17, 2020 6:57 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Strength of an Acid/Base
Replies: 2
Views: 126

### Strength of an Acid/Base

What is Ka and Kb? and what is its relationship to pKa/pKb and the strength/weakness of the acid/base?
Sat Jan 11, 2020 10:14 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Calculating K
Replies: 5
Views: 59

### Re: Calculating K

we don't include those two states because molar concentration of a pure substance doesn't change in a reaction
Sat Jan 11, 2020 10:12 pm
Forum: Ideal Gases
Topic: PV = nRT
Replies: 16
Views: 181

### Re: PV = nRT

P= pressure
V=volume
n=# of moles
R=gas constant
T=temperature
Sat Jan 11, 2020 10:08 pm
Forum: Ideal Gases
Topic: Q and K
Replies: 2
Views: 30

### Re: Q and K

K is used to calculate the concentration or pressure of a species at equilibrium while Q is used to predict the direction of a non-equilibrium reaction (whether the forward or reverse reaction is favored or if Q=K, reaction is at equilibrium). The equilibrium constant (K) is the ratio of the equilib...
Wed Dec 05, 2018 10:06 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar or nonpolar
Replies: 4
Views: 204

### Re: Polar or nonpolar

It doesn't really matter where the Cl atoms are located. If the other two atoms surrounding the central atom are not chlorine, the molecule will be polar.
Wed Dec 05, 2018 10:04 pm
Forum: Naming
Topic: Oxidation Numbers
Replies: 3
Views: 151

### Re: Oxidation Numbers

No, oxidation numbers can be negative,too. For example, the element Fluorine always has an oxidation number of -1.
Wed Dec 05, 2018 10:02 pm
Forum: Hybridization
Topic: hybridization
Replies: 2
Views: 117

### Re: hybridization

I believe that sp3 would be just fine.
Thu Nov 29, 2018 12:24 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Chelate
Replies: 6
Views: 289

### Chelate

When a ligand binds at 1 site, it is monodentate, 2 sites it is bidentate, etc, but what is a chelate and how does it differ from the other ligands? What is its significance?
Thu Nov 29, 2018 12:20 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Number
Replies: 10
Views: 304

### Coordination Number

What is the coordination number and how do you find it?
Thu Nov 29, 2018 12:19 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligands
Replies: 2
Views: 198

### Ligands

I have a general idea of what a ligand is, but what is its significance and how does it relate to the lewis acids/bases?
Tue Nov 20, 2018 10:28 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: higher polarizability
Replies: 4
Views: 204

### higher polarizability

If two ions have the same charge, why is the smaller one the one with higher polarizing power?
Tue Nov 20, 2018 10:26 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Difference in vocabulary terms
Replies: 1
Views: 111

### Difference in vocabulary terms

What is the different between polarizability, polarizing power, and polarization?
Tue Nov 20, 2018 10:25 pm
Forum: Sigma & Pi Bonds
Topic: Pi Bond
Replies: 1
Views: 120

### Pi Bond

A pi bond has most of its electron density between the atomic nuclei.
Why is this statement false? Also, where is most of its electron density located at then?
Thu Nov 15, 2018 12:09 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polarity and Molecular Shape
Replies: 1
Views: 77

### Re: Polarity and Molecular Shape

A molecular is polar if it has a partial negative charge on one side and a partial positive side on the other. The molecular shape shows the final shape of the molecule (since it accounts for the least amount of repulsion from lone pairs too). Molecules in which all of the atoms surrounding the cent...
Thu Nov 15, 2018 12:03 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Arrangement vs Shape
Replies: 3
Views: 219

### Re: Arrangement vs Shape

I think that when asked for the arrangement, it's asking for all single, double, triple bonds as well as lone pair electrons (Lewis Structure). For molecular shape, it may want just the positioning of the atoms without showing what kinds of bonds are attached (almost like a simple 3D drawing) and th...
Thu Nov 15, 2018 11:58 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular shape
Replies: 3
Views: 164

### Re: Molecular shape

The relative strength of the intermolecular forces helps determine the boiling points. Stronger intermolecular bonds require more energy to break, so substances with stronger bonds will have a higher boiling point.(vice versa) Furthermore, more branched particles have LESS surface area compared to a...
Thu Nov 08, 2018 10:00 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Distortion and Polarization
Replies: 3
Views: 375

### Re: Distortion and Polarization

Polarization is the partial or complete separation of the positive and negative electric charges in a nuclear, atomic, molecular, or chemical system. The polarity depends upon the electronegativity of the bonding atoms; most electronegative atoms pull the electronic cloud towards itself. Polarizatio...
Thu Nov 08, 2018 9:56 pm
Forum: Dipole Moments
Topic: dipole interaction
Replies: 2
Views: 119

### dipole interaction

Can someone clarify for me the relationship between polarizability, dipole moments, and fluctuating electron distribution. Also, how does the dissociation energy and interaction potential energy relate to them?
Thu Nov 08, 2018 9:48 pm
Forum: Ionic & Covalent Bonds
Topic: Dipole and Dipole Moments
Replies: 2
Views: 147

### Re: Dipole and Dipole Moments

Dipole moments occur when there is a separation of charge. They can occur between two ions in an ionic bond or between atoms in a covalent bond. They also arise from differences in electronegativity, and the larger the difference in electronegativity, the larger the dipole moment.
Thu Nov 01, 2018 4:39 pm
Forum: Resonance Structures
Topic: Delocalized electrons
Replies: 2
Views: 161

### Delocalized electrons

What does it mean to have delocalized electrons or bonds?
Thu Nov 01, 2018 4:36 pm
Forum: Octet Exceptions
Topic: Boron Trifluoride class example
Replies: 3
Views: 159

### Re: Boron Trifluoride class example

It wouldn't be correct or rather very unlikely (as said by the comment above) because the boron atoms obey a sextet rule. In this compound, the boron atom only has six valence shell electrons, but the octet rule is satisfied by the fluorine atoms around it.
Thu Nov 01, 2018 4:29 pm
Forum: Lewis Structures
Topic: Determining Lewis Structure
Replies: 3
Views: 132

### Re: Determining Lewis Structure

Formal Charge of an atom indicates the gain or loss of an electron while forming covalent bonds. An easy way to understand this concept of formal charge and stability is to think about attaining the lowest formal charge for a given Lewis structure because the one with the lowest formal charges is th...
Sat Oct 27, 2018 10:26 am
Forum: Lewis Structures
Topic: Drawing Lewis Structures with Charges
Replies: 6
Views: 397

### Re: Drawing Lewis Structures with Charges

It is also important to note that when counting electrons, negative ions should have extra electrons placed in their Lewis structures and positive ions should have less electrons than the uncharged molecule. After the Lewis structure of the ion is written, place the entire structure in brackets, and...
Sat Oct 27, 2018 10:23 am
Forum: Trends in The Periodic Table
Topic: Trends in the periodic table & electron configuration
Replies: 5
Views: 237

### Re: Trends in the periodic table & electron configuration

There is definitely a relationship between trends and electron configurations. For example, as the period goes from left to right, the electron configuration changes so that more electrons are added to the levels. This reflects the increase in Ionization Energy, since IE increases going left to righ...
Sat Oct 27, 2018 10:17 am
Forum: Lewis Structures
Topic: Exceptions to octet rule
Replies: 1
Views: 103

### Re: Exceptions to octet rule

H and He are exceptions to the Octet Rule because for them, a full shell contains only 2 electrons (1s shell). Li and Be are metals, so they're likely to lose electrons, therefore becoming cations (Li+, Be2+). When this happens, they revert to the "noble gas" configuration of He, which is ...
Thu Oct 18, 2018 12:16 pm
Forum: Quantum Numbers and The H-Atom
Topic: (6 Ed) Ch. 2 #29
Replies: 1
Views: 80

### (6 Ed) Ch. 2 #29

#29 How many electrons can have the following quantum numbers in an atom? (a) n=2, l=1 (b)n=4, l=2, m1=-2 (c)n=2 (d)n=3 l=2 m1=+1

Thought I knew how to solve this question until I came upon the magnetic quantum number in (b). Can someone please explain what the question is asking and how to start it?
Thu Oct 18, 2018 12:05 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: (6 Ed) Ch.1 #13
Replies: 2
Views: 136

### (6 Ed) Ch.1 #13

I understand how to calculate the wavelength of radiation generated by the transition of n=1 to n=2, but how do you use this value to determine the series it belongs to and the color of light that will be emitted?
Thu Oct 18, 2018 11:59 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Electron Configurations
Replies: 1
Views: 95

### Electron Configurations

After doing a few of Chapter 2's homework problems, I have a couple questions: 1. What is the key difference between ground state and excited state and how does this change the electron configuration of that atom? 2. How do you obtain the magnetic quantum number from quantum number l or any other va...
Sun Oct 14, 2018 8:25 pm
Forum: Properties of Light
Topic: 1A.3 7th Edition Question
Replies: 4
Views: 218

### Re: 1A.3 7th Edition Question

As the frequency decreases, the waves broaden (wavelength increases). The extent of the change is the slope of the wave; therefore, the extent of the change also decreases.
Sun Oct 14, 2018 7:22 pm
Forum: Properties of Light
Topic: Problem A9
Replies: 5
Views: 119

### Re: Problem A9

First, use the equation c=wavelength x frequency(v). Rearrange this equation so that you are looking for the value of v, so v= c/wavelength. Then, convert nm to m. We know that the SI unit for nm is 1x10^-9m, so 2.5nm will be 2.5x10^-9m. Plug in this value as well as the speed of light constant (3.0...
Sun Oct 14, 2018 7:01 pm
Forum: Properties of Electrons
Topic: Energy Q
Replies: 4
Views: 163

### Re: Energy Q

It means that energy is only available in discrete (individual and separate) and small packets called quanta.
Wed Oct 03, 2018 11:04 pm
Forum: Molarity, Solutions, Dilutions
Topic: Fundamentals E3- 7th Edition
Replies: 3
Views: 87

### Re: Fundamentals E3- 7th Edition

In the visual, you see that there are a total of 9 Gallium atoms. Divide 9 by Avogadro's constant; this is the mole amount of Gallium on that balance. Multiply this number by 70 grams/mol (molar mass of Gallium) in order to find the mass of Gallium. Your value should come out to be 1.05x10^-21 Since...
Wed Oct 03, 2018 10:26 pm
Forum: Molarity, Solutions, Dilutions
Topic: Determining the mass of salute for a given concentration
Replies: 1
Views: 154

### Re: Determining the mass of salute for a given concentration

I believe you start by first converting the mL to L because Molarity uses the units mol/L. Since the Molarity and volume is given to you, you can find the amount in moles. After finding this value, find the molar mass of the pentahydrate and multiply this value with the mole amount. This should give...
Wed Oct 03, 2018 10:13 pm
Forum: Empirical & Molecular Formulas
Topic: Molar Mass: E21
Replies: 3
Views: 189

### Re: Molar Mass: E21

To find the amount (in moles), start by calculating the molar mass of the compound and then divide the given mass by this value. In order to find the number of molecules and formula units, multiply the mole amount by Avogadro's constant.