## Search found 96 matches

Sun Feb 23, 2020 11:50 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Nernst Equation usage
Replies: 6
Views: 11

### Nernst Equation usage

I am still confused on when we would need to use the Nernst Equation? Like what kind of questions would be asked that would prompt us to use the equation?
Sun Feb 23, 2020 11:47 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Work and Battery system
Replies: 3
Views: 4

### Work and Battery system

I still don't understand how A battery system has to do with work? Why is the amount of energy that leaves the system -w? And When does energy leave a battery system?
Sun Feb 23, 2020 11:45 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: cell potential
Replies: 3
Views: 10

### cell potential

If the Standard cell potential is an intensive property, then why does concentration affect cell potential using La chatters principle.
Sun Feb 23, 2020 11:42 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: conducting solids
Replies: 2
Views: 10

### conducting solids

What are example so conducting solids and not conduction solids? Whats their significant?
Sun Feb 23, 2020 11:39 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: w max
Replies: 3
Views: 6

### w max

Can someone explain to me what w(max) is and why they will equal change of G at constant T and P
Sun Feb 23, 2020 11:16 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: salt bridge
Replies: 5
Views: 22

### salt bridge

what exactly does the salt bridge do and How does it help neutralize the charge buildup? Also what even causes the charge buildup originally? Can you explain with an example?
Sun Feb 16, 2020 11:56 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: ΔS
Replies: 1
Views: 16

### Re: ΔS

We would use the the equation qsystem=-q surrounds if we know it’s a reversible process, and use the q of surrounds to find S of surroundings. If it’s irreversible isothermal and no work is and we find that no heat is given of my the system then we know the delta S of surroundings is 0.
Sun Feb 16, 2020 11:52 pm
Forum: Ideal Gases
Topic: When to use equation
Replies: 3
Views: 26

### When to use equation

Ik that you would use this equation to find a value such as moles when given temp pressure and volume. However, can you use this equation to get the moles of reactant then go to moles of product and then find the concentration of the product using the volume?
Sun Feb 16, 2020 11:49 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Second law of thermodynamics
Replies: 6
Views: 15

### Second law of thermodynamics

Can someone explain to me the second law of thermodynamics? I know what it says but I’m struggling to understand the concept behind it.
Sun Feb 16, 2020 11:41 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Hc vs Hf
Replies: 3
Views: 12

### Hc vs Hf

Is there a difference between Hc and Hf?
Would you use them exactly them say as in products minus reactants?
Sun Feb 16, 2020 11:40 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Limiting reactant and heat
Replies: 4
Views: 15

### Limiting reactant and heat

I saw a lot of questions with using limiting react and then finding heat with it, and I don’t understand how a limiting reactant has anything to do with heat? Can someone explain?!
Sun Feb 16, 2020 11:37 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Ph
Replies: 8
Views: 28

### Ph

When given the pH, is it always the ph at equilibrium so therefore we can find the h+ at equillibrium?
If not how would it be worded when it refers to initial h+ concentration
Mon Feb 10, 2020 12:57 am
Forum: Phase Changes & Related Calculations
Topic: delta T
Replies: 1
Views: 10

### delta T

for delta T is it always Tf-Ti because lets say a copper at 100 degrees celsius were to drop in temperature, is the delta T Tf-100 or 100 -Ti
Mon Feb 10, 2020 12:19 am
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: standard entropy meaning
Replies: 3
Views: 7

### standard entropy meaning

What is the meaning behind standard entropy? Is it just entropy at a specific temperature?
Mon Feb 10, 2020 12:16 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Entropy of universe
Replies: 3
Views: 17

### Entropy of universe

Does anyone have an explanation on why it is a spontaneous process if the change in entropy of the universe is +? Why is this favorable.
Mon Feb 10, 2020 12:11 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: identifying systems
Replies: 3
Views: 15

### identifying systems

I still have difficulties identifying what systems are, will we need to identify systems such as open closed or isolated for the midterm? If so, does anyone have a trick that would be able to help me?
Mon Feb 10, 2020 12:05 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: ideal gas equation.
Replies: 2
Views: 24

### ideal gas equation.

Can someone explain the equation Utotal= 3/2 nRT. I don't understand where this equation cam from. Also Why does then Delta U equal 0 because delta T is 0. Why is delta T=0.
Mon Feb 10, 2020 12:02 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 4C.3
Replies: 1
Views: 19

### 4C.3

Hi, 4C.3 says "Calculate the final temperature and the change in enthalpy when 765 J of energy is transferred as heat to 0.820 mol Kr(g) at 298 K and 1.00 atm (a) at constant pressure; (b) at constant vol- ume. Treat the gas as ideal." I get how you have q and you have separate equations f...
Sun Feb 09, 2020 11:59 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: irreversible vs reversible
Replies: 3
Views: 17

### irreversible vs reversible

hi i still don't get the difference between a irreversible and reversible reaction, What are examples of each??
Sun Feb 09, 2020 11:59 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: constant pressure system
Replies: 2
Views: 11

### constant pressure system

I still don't get a constant pressure system. Like what is an example of it?
Sun Feb 09, 2020 11:58 pm
Forum: Calculating Work of Expansion
Topic: work done at equilibrium
Replies: 1
Views: 16

### work done at equilibrium

what is the importance of the equation of the work done at equilibrium? (the integral). Because it still gets you the same equation?
Sun Feb 02, 2020 11:47 pm
Forum: Calculating Work of Expansion
Topic: Area under the curve
Replies: 3
Views: 18

### Area under the curve

Right before lecture ended, Dr. Lavelle was talking about areas under a curve to measure work and other stuff. What do we have to know about area under a curve because I know that with integrals you are able to measure the area under a curve, but why is that important and do we even have to know that?
Sun Feb 02, 2020 11:45 pm
Forum: Calculating Work of Expansion
Topic: Reversible
Replies: 7
Views: 14

### Reversible

In the notes, It says since a system is at equilibrium it is a reversible process? What does that mean? What is not a reversible process? What is the importance of it becoming a reversible process?
Sun Feb 02, 2020 11:35 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Gases vs liquids and solids
Replies: 1
Views: 8

### Gases vs liquids and solids

Why are we not able to calculate the change in enthalpy, work, temperature, etc. in liquid and solids? Why is it only gases?
Sun Feb 02, 2020 11:30 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: q and w
Replies: 10
Views: 49

### q and w

When reading questions, is there a quick trick we can use to quickly know if we are gonna end up with a positive or negative q and a positive or negative w?
Sun Feb 02, 2020 11:27 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Changing energy of systems
Replies: 1
Views: 6

### Changing energy of systems

I am still confused on the different kinds of systems and how we change energy in each of them. In the notes it says we do work on a system only in a closed system. Why cant we do work on an open system. It also says we only heat or cool a closed system, Why?
Sun Jan 26, 2020 11:32 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: checking approximation
Replies: 4
Views: 13

### checking approximation

If the K of reaction is less than 10^-3, but when you check your approximation and it is more than 5%, then does that mean you can't approximate and have to use the quadratic formula?
Sun Jan 26, 2020 11:29 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard enthalpy of formation
Replies: 1
Views: 17

### Standard enthalpy of formation

If by definition, the standard enthalpy of formation of an element in its most stable form is zero, and the standard enthalpy of 02 is zero, then does that mean Graphite which is the most stable form of C has a standard enthalpy of formation? Also, when will we know when things are in their most sta...
Sun Jan 26, 2020 11:24 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: pressure and enthalpy
Replies: 5
Views: 21

### pressure and enthalpy

how exactly is enthalpy affected by pressure?
Sun Jan 26, 2020 11:21 pm
Forum: Phase Changes & Related Calculations
Topic: Temp. of sample
Replies: 4
Views: 9

### Temp. of sample

What exact did Dr. Lavelle mean when he said because heat is required during melting or boiling, the temp of sample remains constant even though heat is being supplied. Did he mean it stays constant until the transition is complete? Like what is a real life example of this?
Sun Jan 26, 2020 11:19 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Method 2 example
Replies: 3
Views: 14

### Method 2 example

In the method 2 example with CH2=Ch2, is the reason he doesn't include the bond enthalpy of the C-H bonds on the reactants side of the equation is because the products side has one more C-H bonds than the reactants side?
Sun Jan 19, 2020 11:06 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: pKa and pH
Replies: 1
Views: 16

### Re: pKa and pH

The pH and pka are related in that the lower the pH, the higher the concentration of hydrogen ions, and the the lower the pKa, the stronger the acid and the greater its ability to donate protons. So both can describe a strong acid. However, pH depends on concentrations of the solution, while the pKa...
Sun Jan 19, 2020 10:58 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE tables for reverse rxns
Replies: 4
Views: 13

### Re: ICE tables for reverse rxns

You would treat the reverse reaction just how you treated the front reaction. You have initial concentrations and the only difference is that you minus x from the products and add x to the reactants, and then use the equallibrum concentrations and your K to solve for x.
Sun Jan 19, 2020 10:49 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Approximations
Replies: 2
Views: 4

### Approximations

Lets say the equilibrium concentration for a reactant is 0.155-x and we can approximate, when we approximate and we get rid of the minus x, do we still include the minus x, when we are asked what the final solution for the reactant?
Sun Jan 19, 2020 10:46 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Adding a molecule thats not in reaction
Replies: 2
Views: 8

### Adding a molecule thats not in reaction

Would adding a molecule that is not in the reaction affect the production of products or reactants because there is more pressure in the system?
Sun Jan 19, 2020 10:38 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: KNO2 and buffers
Replies: 2
Views: 14

### KNO2 and buffers

Does NO2- pick up a proton and make the solution basic? How do buffers work? Are they used to neutralize a salt?
Sun Jan 12, 2020 7:12 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: stoichiometric coefficients
Replies: 5
Views: 27

### stoichiometric coefficients

how are stoichiometric coefficients involved in Equilibrium? Why when they are the same, its still in equilibrium?
Sun Jan 12, 2020 7:03 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: "Quick way" part in Lecture
Replies: 7
Views: 43

### Re: "Quick way" part in Lecture

Yes, what does that mean?
Sun Jan 12, 2020 6:58 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Inert gas
Replies: 6
Views: 26

### Inert gas

What is the explanation behind why when inert gas is added and pressure increases, reactant product and volume still stay the same?
Sun Jan 12, 2020 6:57 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: "Quick way" part in Lecture
Replies: 7
Views: 43

### "Quick way" part in Lecture

What are examples that can differentiate when it says " V decreases and more moles of gas on left" and "V decreases, and more moles of gas on right"? I was very confused when looking over my notes again.
Sun Jan 12, 2020 6:56 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: pressure and volume
Replies: 4
Views: 17

### pressure and volume

How are pressure and volume related, why when you double P that means Volume is halved.
Sun Jan 12, 2020 6:54 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: increasing yield of NH3
Replies: 3
Views: 19

### Re: increasing yield of NH3

To increase yield of NH3, you would need to increase the amount of reactants
Sat Dec 07, 2019 11:27 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Double bond oxygen
Replies: 1
Views: 26

### Double bond oxygen

Why isn't a oxygen that has lone pairs but is double bonded to something not considered a ligand?
Sat Dec 07, 2019 11:23 pm
Forum: Ionic & Covalent Bonds
Topic: Coulombs equation
Replies: 1
Views: 24

### Coulombs equation

Can somebody explain Coulombs equation to me? What do the q1 and q2 stand for?
Sat Dec 07, 2019 11:21 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: different acids
Replies: 1
Views: 36

### different acids

Does anyone know,if for the test we need to know the different formulas for acetic acid, formic acid, and different kinds of acids like that
Fri Dec 06, 2019 1:08 am
Forum: Octet Exceptions
Topic: Incomplete octets
Replies: 1
Views: 26

### Incomplete octets

Why are incomplete octets formed? Like whats the reasoning behind how they are able to be formed?
Fri Dec 06, 2019 1:07 am
Forum: Ionic & Covalent Bonds
Topic: Coulombs equation
Replies: 1
Views: 24

### Coulombs equation

Can someone explain coulombs equation to me?
It says F(e)=(kQ1Q2)/r^2
Fri Dec 06, 2019 1:05 am
Forum: Properties of Light
Topic: Light Absorbed/ emitted
Replies: 4
Views: 38

### Light Absorbed/ emitted

When is light emitted and when is it absorbed. Why was it positive on the midterm when light is absorbed? And What does it mean for light to be emitted or absorbed?
Sun Dec 01, 2019 11:50 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Lecture
Replies: 3
Views: 33

### Lecture

Can someone explain to me what Professor Lavelle meant when he said "Resulting anion must be stable, and that oxyacids more readily lose H+ if resulting anion is stabilized by e- withdrawing atoms which decline and stabilize negative charge."
Sun Dec 01, 2019 11:46 pm
Forum: Bronsted Acids & Bases
Topic: Equilibrium Arrows for Strong Acid/Base Equations
Replies: 1
Views: 17

### Re: Equilibrium Arrows for Strong Acid/Base Equations

During lecture, Professor Lavelle said it would usually be a singe arrow if its a strong acid or base because it is completely dissociating, however if you but the equilibrium arrows it is technically not wrong as long as you explain that it is a strong acid and it is mostly a forward reaction.
Sun Dec 01, 2019 11:44 pm
Forum: Polyprotic Acids & Bases
Topic: Polyprotic acids and bases
Replies: 2
Views: 25

### Polyprotic acids and bases

Hi, I know this is a dumb question, but what are polyprtoic acids and bases in simple terms. Can you also give examples?
Sun Dec 01, 2019 11:31 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: TEST 2 POLAR molecule
Replies: 6
Views: 36

### TEST 2 POLAR molecule

Why is the molecule that shows the lewis structure of CCl2H2 a polar molecule, I thought that the Cl atoms are pulling different ways so it makes the overall molecule non polar? I think the question number was 6.
Sun Dec 01, 2019 11:26 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Acting as a base
Replies: 1
Views: 20

### Re: Acting as a base

According to the lewis definition, as long as it has an electron pair to donate it can be considered a base, but there are exceptions such as nobles gases who do have lone pairs but don't act as a base.
Sun Dec 01, 2019 11:19 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Acid and water
Replies: 2
Views: 18

### Acid and water

When an Acid combines with water, does it always yield H30+ and when doing pH and your giving the concentration of H30+, do you take the negative log of that to find the pH?
Sun Nov 24, 2019 11:17 pm
Forum: Naming
Replies: 3
Views: 25

If thats true then why for his example of [Co(NH3)5Cl]CL.2H2O he said it was Penta Ammine Chloro Cobalt II Chloride DiHydrate. Why is the chloride not Chloro?
Sun Nov 24, 2019 11:12 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: lecture notes
Replies: 2
Views: 25

### lecture notes

Can someone explain what Professor Lavelle was talking about when he said that 6 ligands at the corners of an octahedron: octahedral complex. Can someone give me an example of this. Also when eh says 4 ligands at corners of tetrahedron form a tetrahedral complex.
Sun Nov 24, 2019 11:08 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination complexes
Replies: 3
Views: 22

### Re: Coordination complexes

A coordination complex is just basically a product of a lewis acid-base reaction where Lewis bases, which are the neutral atoms that have lone pairs to donate to a lewis acid, which are the transition metals. The bonds that they form are coordinate covalent bonds.
Sun Nov 24, 2019 11:01 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligands
Replies: 4
Views: 27

### Re: Ligands

A ligand is basically an ion or molecule that binds to a central atom that is usually a transition metal to form a coordination complex. The Ligand is the one that has the extra lone pair and is the lone pair donor.
Sun Nov 24, 2019 3:50 pm
Forum: Naming
Topic: Coordination number
Replies: 7
Views: 33

### Coordination number

I am a bit confused on what determines coordination compound. Can anyone give me an example and explain. Thank you!
Sun Nov 17, 2019 11:52 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: electronegativity
Replies: 6
Views: 24

### Re: electronegativity

It goes along the same guidelines as ionization energy. smaller molecule, with a greater nuclear charge, will attracts its electrons more.
Sun Nov 17, 2019 11:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: electronegativity
Replies: 6
Views: 24

### Re: electronegativity

there is a pattern in the periodic table, as you go up and right, the electronegativity of the atoms rise. But basically, its the how much an atom attracts electrons. And this electronegativity is determined by looking at its atomic number (nuclear charge) and the amount of valence electrons.
Sun Nov 17, 2019 11:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSPER
Replies: 7
Views: 50

### Re: VSPER

An even simpler explanation is that it is basically the shapes of molecules when taking in consideration that electrons have repulsion and that a molecule tries to minimizes this repulsion by arranging its bonds and lone pairs that it has around the central atom. Its basically just a very simple dra...
Sun Nov 17, 2019 11:37 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: polar vs non polar
Replies: 6
Views: 40

### polar vs non polar

Can we distinguish a polar molecule between a non polar molecules by just looking at the bonds inside the molecule and see if the there is dipole moments and if they cancel out, or can we just have to know right away by how the structure is drawn?
Sun Nov 17, 2019 11:32 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: sulfite vs NH3
Replies: 2
Views: 28

### sulfite vs NH3

Why in the lecture the bond angles for sulfite which has 3 bond pairs and one lone pair, is different than the NH3 which also has 3 bond pairs and 1 lone pair
Sun Nov 17, 2019 11:31 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 9
Views: 41

### Bond Angles

Will we have to memorize all the bond angles for each of the shapes? If so, does anyone know a quick and easy way because I keep mixing them up?
Sun Nov 10, 2019 11:44 pm
Forum: Quantum Numbers and The H-Atom
Topic: The spin of a quantum number
Replies: 6
Views: 45

### Re: The spin of a quantum number

If u are asked what spin a certain electron has in its orbital, you won't be able to tell. However, when filling out orbitals, electrons first fill different orbitals and have an up spin, and then after complete the filling of the orbitals with down spin electrons. So you can tell which spin the las...
Sun Nov 10, 2019 11:39 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: Dipole-Dipole vs Dipole-Induced
Replies: 2
Views: 16

### Dipole-Dipole vs Dipole-Induced

Whats the difference between Dipole-Dipole forces and Dipole-Induced? Are there similarities also.
Sun Nov 10, 2019 10:45 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: 3F. 1
Replies: 1
Views: 20

### Re: 3F. 1

Basically, the different intermolecular forces are london dispersion, hydrogen bonding, and dipole-dipole. For a) there would be hydrogen bonding between two molecules of this because of the H-N Bonds, also there would be dipole-dipole because of the dipole moments of this molecule, and obviously lo...
Sun Nov 10, 2019 10:38 pm
Forum: Empirical & Molecular Formulas
Topic: Midterm question 1
Replies: 6
Views: 81

### Midterm question 1

Does anyone know how they did question 1, the empirical formula one, on the midterm? I did not know how I was able to take the grams of some of the products and use mole to mole ratio to go to the empirical formula for the reactant.
Wed Nov 06, 2019 1:52 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Delta E
Replies: 1
Views: 24

### Delta E

When Delta E is negative what does that mean? Does that mean that emission vs it being positive which means absorption? Also when an electron is excited to a higher level, does that mean delta E would be positive?
Sun Nov 03, 2019 11:58 pm
Forum: Properties of Electrons
Topic: Molecular spectroscopy
Replies: 1
Views: 50

### Re: Molecular spectroscopy

They are actually very similar but basically in molecular spectroscopy, it is the study of light by molecules. it is saying that electrons in molecules can be excite to higher energy states. In atomic spec, it is the interactions of this but in atoms, matter that is independent of bonds.
Sun Nov 03, 2019 11:44 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic and Covalent bonds
Replies: 1
Views: 18

### Ionic and Covalent bonds

Why are ionic compounds made from a metal to a nonmetal and why are covalent bonds made from non-metals only? What is the reasoning? Also, is this rule always true?
Sun Nov 03, 2019 11:40 pm
Forum: Octet Exceptions
Topic: Lewis Acids and Bases?
Replies: 11
Views: 76

### Lewis Acids and Bases?

Can someone Explain what Lewis Acids and Bases are and why they are an exception to the often rule? Also, what different rxns are they involved in?
Sun Nov 03, 2019 11:30 pm
Forum: DeBroglie Equation
Topic: Dino Nuggets 6a
Replies: 1
Views: 64

### Dino Nuggets 6a

The question says, "A new element GarBreadium is discovered to have molar mass 3.157 g∙mol-1. The GarBreadium atom travels at an average speed of 1.35x103 m∙s-1 at room temperature. What is the average wavelength of the GarBreadium atom at room temperature?" What is the mass of the atom? a...
Sun Nov 03, 2019 11:26 pm
Forum: Octet Exceptions
Replies: 5
Views: 49

Why do Radicals happen? Also, What do we have to know about them for our midterm?
Mon Oct 28, 2019 12:13 am
Forum: *Shrodinger Equation
Topic: wave function
Replies: 3
Views: 45

### wave function

do we need to know the wavefunctions equations, and the potential energy equation? If so can someone explain them to me? and whats their purpose?
Sun Oct 27, 2019 11:58 pm
Forum: Photoelectric Effect
Topic: photoelectric effect book example
Replies: 2
Views: 20

### photoelectric effect book example

An example in the book in 1B it says You need to make some estimates of the physical properties involved. The speed of an electron emitted from the surface of a sample of potassium by a photon is 668 km?s21. (a) What is the kinetic energy of the ejected electron?, and in the answer in the book it sa...
Sun Oct 27, 2019 5:02 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic v Covalent Bond
Replies: 3
Views: 49

### Re: Ionic v Covalent Bond

basically every atom has an electronegativity, which is how much an atom attracts electrons. Therefore the reason it says if the electronegativity difference is more than 2 consider it ionic is because at that point the electrons are not being shared anymore and instead one atom takes the electron w...
Sun Oct 27, 2019 4:56 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge Vs. Oxidation Number
Replies: 4
Views: 34

### Re: Formal Charge Vs. Oxidation Number

Basically they are very similar the only big difference is that formal charge assumes all the bonding electrons were divided equally between atoms while in oxidation numbers we assign numbers to the more electronegative atom in the bond.
Sun Oct 27, 2019 4:52 pm
Forum: Octet Exceptions
Topic: Octet rule exception
Replies: 2
Views: 20

### Octet rule exception

Professor Lavelle was talking about exceptions to the octet rule because they have a d-orbital, does this mean every atom with a d orbital has an exception to the octet rule. Also, do these exceptions affect the drawings of lewis structure so that there are more than 8 electrons around an atom?
Sun Oct 20, 2019 12:17 pm
Forum: Quantum Numbers and The H-Atom
Topic: d orbitals
Replies: 4
Views: 56

### d orbitals

Why do electrons in the d orbitals have less energy than electrons in the s orbitals such as why does it go 3d^2 4s^2
Sat Oct 19, 2019 3:57 pm
Forum: Properties of Electrons
Topic: Velocity
Replies: 1
Views: 36

### Velocity

Can someone explain how velocity plays a role in wavelength and electrons as a whole? Like i get the equation but can someone explain the concept behind the equation.
Sat Oct 19, 2019 3:51 pm
Forum: Properties of Electrons
Topic: Balmar and Lyman series
Replies: 2
Views: 24

### Balmar and Lyman series

For the series I don't understand when the question says N(1)= 2 and N(2)= 3,4 what does the n(1) and N(2) stand for.
Sat Oct 19, 2019 3:41 pm
Forum: Properties of Electrons
Topic: Photo and electron energy
Replies: 4
Views: 27

### Photo and electron energy

Does the energy difference between to energy levels have to be exact for the energy to be absorbed? Like what happens when the photons energy is more than the energy difference between energy level? Is that where the equation E(excess)= E(photon)-E(energy to remove e-)
Tue Oct 15, 2019 9:11 pm
Forum: Properties of Light
Topic: Defraction patters
Replies: 3
Views: 53

### Defraction patters

I am a bit confused about diffraction patters and wavelike properties. Do both light and electrons have wave like properties? If so, does that mean they both have Difraction patterns. Also, what are diffraction patters?
Sun Oct 13, 2019 11:14 pm
Forum: Significant Figures
Topic: Tests and Significant Figures
Replies: 6
Views: 78

### Re: Tests and Significant Figures

For sig figs, if you are adding and subtracting you use the least amount of numbers after the decimal place and if u are multiplying or dividing you use the least amount of sig figs overall for your answer. However, one good rule of thumb is I would round for sig figs only at end.
Sun Oct 13, 2019 10:57 pm
Forum: Properties of Electrons
Topic: Electrons wavelengths and frequency
Replies: 2
Views: 34

### Electrons wavelengths and frequency

so is an electron is its own energy source? does that mean it has wavelengths and frequency? and I Just don't get how if its excited it drops down energy levels? I thought if its excited it is given off
Sun Oct 13, 2019 7:32 pm
Forum: Photoelectric Effect
Topic: Electrons ejected based on wavelength
Replies: 3
Views: 35

### Re: Electrons ejected based on wavelength

yes, basically with long wavelengths it means the frequency is low, and therefore the strength of the energy is low and therefore can't eject the electrons in the experiment, and with every surface there is a minimum energy/frequency required to remove an electron.
Sun Oct 13, 2019 7:29 pm
Forum: Properties of Electrons
Topic: Planck's constant
Replies: 2
Views: 40

### Re: Planck's constant

yes, this constant basically directly relates the energy carried by a photon with its frequency, and that's how we get the equation E=hf. However, the constant is used in other scenarios too. Basically, a man by the name of Max Planck was studying black body emissions, and used the constant to expla...
Sun Oct 13, 2019 7:12 pm
Forum: Properties of Light
Topic: Intensity and Frequency
Replies: 2
Views: 29

### Re: Intensity and Frequency

basically, the energy of a photon is related to the frequency and the intensity is related to the number of photons. Therefore, when we talk about energy strength of something, we are talking about the frequency.
Thu Oct 03, 2019 12:29 am
Forum: Limiting Reactant Calculations
Topic: M 15
Replies: 4
Views: 40

### Re: M 15

Yes so the process is 1) find the limiting reactant 2) find the theoretical yield 3) use the formula of percent yield which is actual/theoretical x 100% it is very simple just make sure you have your numbers correctly, and I wouldn't round to sig figs during the process of calculations because u mig...
Thu Oct 03, 2019 12:22 am
Forum: Properties of Light
Topic: Properties of light in class
Replies: 3
Views: 62

### Properties of light in class

we talked a little about the properties of light in class today and I was a bit confused. Where does the value Hertz come from and how does that have to do with frequency, amplitude, and light in general. Also, when we are talking about strength of light what do we usually look at? Sorry if my quest...
Thu Oct 03, 2019 12:15 am
Forum: Empirical & Molecular Formulas
Topic: Problem F5 (7th Edition)
Replies: 3
Views: 440

### Re: Problem F5 (7th Edition)

Yes those numbers look right, and the steps that amy gave were really good too. An extra tip that I would give u is that just to make sure you mass percentages are correct, add all them up and they should add to 100%, if not you did something wrong.
Thu Oct 03, 2019 12:09 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: E.29 b and c
Replies: 3
Views: 61

### E.29 b and c

E.29 A chemist measured out 8.61 g of copper(II) chloride tetrahydrate, CuCl2 4H2O. (a) How many moles of CuCl2 4H2O were measured out? (b) How many moles of Cl ions are present in the sample? (c) How many H2O molecules are present in the sample? d) What fraction of the total mass of the sample was ...
Wed Oct 02, 2019 11:45 pm
Forum: Significant Figures
Topic: When are zeroes significant in calculations?
Replies: 5
Views: 54

### Re: When are zeroes significant in calculations?

Yes sometimes zeros are included and sometimes they are not. You only include zeros when they are after a decimal(trailing zeros) and in between numbers. Therefore, 20.0 has 3 sig figs, and 204.05 has 5 sig figs. However, zeros before numbers in a decimal are not significant such as 0.006 only has 1...
Wed Oct 02, 2019 11:42 pm
Forum: Limiting Reactant Calculations
Topic: Why does the Limiting Reactant only affect the other reactant and not affect the product? [ENDORSED]
Replies: 4
Views: 71

### Re: Why does the Limiting Reactant only affect the other reactant and not affect the product?[ENDORSED]

A limiting reactant is a substance that is limited because it is totally consumed when the reaction happens, and when it is consumed the reaction can't occur without it. Therefore, i wouldn't think of it as not allowing water to reach its full potential rather it should be that we have excess amount...