Search found 102 matches

by ABombino_2J
Wed Mar 11, 2020 12:46 pm
Forum: General Rate Laws
Topic: intermediates
Replies: 12
Views: 69

Re: intermediates

Yes. Because they are formed and used up they cancel each other out in the overall equation.
by ABombino_2J
Wed Mar 11, 2020 12:42 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Catalysts vs. Intermediates
Replies: 8
Views: 71

Re: Catalysts vs. Intermediates

A catalyst exits in the beginning of a set of reactions and also comes out at the end of a set of reaction, so it is used up and then produced. An intermediate is formed and then used up.
by ABombino_2J
Wed Mar 11, 2020 12:41 pm
Forum: Second Order Reactions
Topic: linear graph
Replies: 7
Views: 130

Re: linear graph

To see if the slope is positive or negative you take the value of k from the equation.
by ABombino_2J
Wed Mar 11, 2020 12:38 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: How to determine Q
Replies: 4
Views: 64

Re: How to determine Q

When you write out the half reactions and add them to make the complete equation the answer will result in the reaction that you base Q off of.
by ABombino_2J
Wed Mar 11, 2020 12:34 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Concentration
Replies: 9
Views: 69

Re: Concentration

You need to use the NERNST equation album make sure you set up Q as [anode]/[cathode].
by ABombino_2J
Mon Mar 09, 2020 12:58 am
Forum: Balancing Redox Reactions
Topic: oxidation number
Replies: 10
Views: 103

Re: oxidation number

You need to take the known charges of the elements in the molecule and then find the different between that and the overall charge of the reaction.
by ABombino_2J
Mon Mar 09, 2020 12:56 am
Forum: Balancing Redox Reactions
Topic: Half rxns
Replies: 27
Views: 410

Re: Half rxns

Balance it the same as you would with acidic but add OH- at the end to cancel out the H+.
by ABombino_2J
Sun Mar 08, 2020 10:17 pm
Forum: Balancing Redox Reactions
Topic: Why do we flip E for oxidation?
Replies: 13
Views: 97

Re: Why do we flip E for oxidation?

You are only supposed to flip E when you are given reduction potentials and you are looking for oxidation potentials. This is almost all the time becase our appendix gives reduction potentials.
by ABombino_2J
Sun Mar 08, 2020 10:14 pm
Forum: General Rate Laws
Topic: Rate limiting step
Replies: 12
Views: 94

Re: Rate limiting step

The rate limiting step is the slowest reaction that occurs.
by ABombino_2J
Sun Mar 08, 2020 10:10 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Catalysts
Replies: 8
Views: 69

Re: Catalysts

Lowering the activation energy and increasing the rate are the main functions of a catalyst. It’s important to note they go into the reaction and come out; in other words, they are not consumed.
by ABombino_2J
Tue Feb 25, 2020 4:14 pm
Forum: Balancing Redox Reactions
Topic: Acids and Bases
Replies: 4
Views: 82

Re: Acids and Bases

You need to add H2O to balance the oxygens and H+ to balance the hydrogens. When you add OH- because the solution is basic you must add it to both sides of the reaction to make H2O by combing H+ and OH-.
by ABombino_2J
Tue Feb 25, 2020 4:10 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: standard potential of a redox reaction
Replies: 3
Views: 46

Re: standard potential of a redox reaction

Because E is intensive it does not rely on the amount products or reactants present, so you would NOT multiply the E value. The only time you alter the E value is when you flip the equation; then you would multiply it my -1.
by ABombino_2J
Tue Feb 25, 2020 4:05 pm
Forum: Balancing Redox Reactions
Topic: Platinum in cell diagram
Replies: 10
Views: 108

Re: Platinum in cell diagram

Graphite and gold are some other metals that also work in place of platinum.
by ABombino_2J
Tue Feb 25, 2020 3:56 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cathode vs Anode
Replies: 6
Views: 88

Re: Cathode vs Anode

The cathode is the one being reduced and the anode is the one being oxidized.
by ABombino_2J
Tue Feb 25, 2020 3:54 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gas constant R
Replies: 5
Views: 51

Re: Gas constant R

Whenever you are deciding which gas constant to use, look at your units and pick the R that will cancel them out.
by ABombino_2J
Tue Feb 25, 2020 3:05 pm
Forum: Balancing Redox Reactions
Topic: Which equation do we flip?
Replies: 6
Views: 74

Re: Which equation do we flip?

If it is a spontaneous galvanic cell, flip whichever equation will give you a positive Ecell. If they say it is non spontaneous, or the batter is dead, make the Ecell negative.
by ABombino_2J
Tue Feb 25, 2020 3:01 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Spontaneity
Replies: 8
Views: 83

Re: Spontaneity

Yes, Delta G = -nFEcell so if Ecell is positive Delta G must be negative and therefore spontaneous. Also keep in mind a negative delta G and positive Ecell means that the battery is working well.
by ABombino_2J
Tue Feb 25, 2020 2:47 pm
Forum: Balancing Redox Reactions
Topic: Flipping Reactions
Replies: 4
Views: 49

Re: Flipping Reactions

If it is a battery you want the Ecell to be positive so flip whichever reaction will give you a positive Ecell value.
by ABombino_2J
Tue Feb 25, 2020 2:43 pm
Forum: Balancing Redox Reactions
Topic: half reaction
Replies: 10
Views: 117

Re: half reaction

Use H2O to balance the Oxygen in the reaction and then use H+ to balance the Hydrogen as a result of adding H2O. Then balance the charges by adding e-. Multiply the half reactions so that the charges cancel each other out then add the reactions together. If it is a basic solution add OH- to both sid...
by ABombino_2J
Tue Feb 25, 2020 2:40 pm
Forum: Balancing Redox Reactions
Topic: Acid and Bases in Redox Reaction
Replies: 4
Views: 74

Re: Acid and Bases in Redox Reaction

You add H+ to the half reactions to balance the hydrogens on either side. You add OH- to both sides to the entire creation to get rid of H+ and turn it into H2O when you are balancing in basic solution.
by ABombino_2J
Tue Feb 25, 2020 2:37 pm
Forum: Balancing Redox Reactions
Topic: Balancing Redox Reactions
Replies: 7
Views: 62

Re: Balancing Redox Reactions

Only cancel the H+ with OH- when it says to balance the equation in basic solution.
by ABombino_2J
Fri Feb 21, 2020 1:45 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Electrode
Replies: 4
Views: 43

Re: Electrode

The Pt electrode simply acts as an inert conductor to facilitate e- transfer.
by ABombino_2J
Fri Feb 21, 2020 1:44 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: E
Replies: 5
Views: 41

Re: E

If the reaction spontaneous E is positive because deltaG is negative.
by ABombino_2J
Fri Feb 21, 2020 1:39 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Potential Difference
Replies: 2
Views: 35

Re: Potential Difference

Potential difference = work/charge. From this you can derive Wmax=deltaG=-nFE which can tell you if the reaction is favorable or not.
by ABombino_2J
Fri Feb 21, 2020 1:36 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: E v E(standard)
Replies: 4
Views: 39

Re: E v E(standard)

E standard is the E only under standard conditions.
by ABombino_2J
Sun Feb 16, 2020 10:19 pm
Forum: Balancing Redox Reactions
Topic: easier to split?
Replies: 6
Views: 63

Re: easier to split?

The splitting of the redox reaction into two half reactions makes it easier to balance the reaction by adding electrons and therefore adding h+ to the opposite side.
by ABombino_2J
Tue Feb 11, 2020 4:22 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: State of matter affect entropy
Replies: 3
Views: 37

Re: State of matter affect entropy

Typically entropy will increase as heat is added and vice-versa because deltaS= delta q/T
by ABombino_2J
Tue Feb 11, 2020 4:18 pm
Forum: Ideal Gases
Topic: reversing reactions
Replies: 14
Views: 180

Re: reversing reactions

K reverse : 1/k
K*n : K^n
K*m: K^(1/m)
by ABombino_2J
Tue Feb 11, 2020 4:15 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Partial Pressure equilibrium problems
Replies: 2
Views: 33

Re: Partial Pressure equilibrium problems

Many times you will need to use PV=nRt to find the partial pressures of all the gases, then use an ICE table just like you would with contractions and a Kp value.
by ABombino_2J
Tue Feb 11, 2020 4:09 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Adding Inert Gas
Replies: 20
Views: 292

Re: Adding Inert Gas

Adding an inert gas increases the pressure of the system but will not affect the equilibrium constant K or Q because these gases do not react easily because they have a full octet
by ABombino_2J
Tue Feb 11, 2020 4:03 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Pizza Rolls Question 5!! Help
Replies: 3
Views: 67

Re: Pizza Rolls Question 5!! Help

No it shouldn't matter because the volume is no longer changing. You can think of it as doing the volume change with constant temperature then the temperature change with the constant final volume.
by ABombino_2J
Sun Feb 02, 2020 10:04 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: accuracy of bond enthalpies
Replies: 8
Views: 81

Re: accuracy of bond enthalpies

The bond enthalpy method is the least accurate because all the bond enthalpy es are averages of many molecules.
by ABombino_2J
Sun Feb 02, 2020 9:54 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: boltzmann equation
Replies: 4
Views: 45

Re: boltzmann equation

Yes. I’m pretty sure W is number of states^number of particles.
by ABombino_2J
Sun Feb 02, 2020 9:41 pm
Forum: Phase Changes & Related Calculations
Topic: Relevance of Phase Changes
Replies: 9
Views: 69

Re: Relevance of Phase Changes

When calculating the enthalpy change you need to add the enthalpy as a result of change in temperature as well as the enthalpy that comes from a phase change.
by ABombino_2J
Sun Feb 02, 2020 9:36 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy
Replies: 7
Views: 63

Re: Enthalpy

q=enthalpy only when the pressure is constant because no other work is being done.
by ABombino_2J
Sun Feb 02, 2020 9:33 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hess’ Law
Replies: 10
Views: 145

Re: Hess’ Law

Hess’ Law is essentially the definition of a state function for enthalpy.
by ABombino_2J
Sun Jan 26, 2020 11:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Acid and Base Concentration
Replies: 3
Views: 55

Re: Acid and Base Concentration

If you had the concentration of an acid or base you would need to find the [H3O+] or [OH-] then find the PH of the acid. If the PH or POH are very very low they are most likely strong acids/bases.
by ABombino_2J
Sun Jan 26, 2020 11:23 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Kw Equations
Replies: 10
Views: 153

Re: Kw Equations

ka*kb=kw=10^-14
pka+pka=pkw=14 (you get this by taking the -log of the first equation)
Also, these equations are on the equation sheet just replace [H3O+] with ka, [OH-] with kb, pH with pka, and POH with pkb.
by ABombino_2J
Sun Jan 26, 2020 11:17 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Ka and Kb
Replies: 10
Views: 123

Re: Ka and Kb

All acids/bases have a Ka or a Kb but strong acids and bases have such large Ka and Kb's that they are considered to fully dissociate.
by ABombino_2J
Sun Jan 26, 2020 11:11 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Reaction Shifts Left or Right
Replies: 15
Views: 170

Re: Reaction Shifts Left or Right

Whenever you see heat added or released from a system, you can treat it just like the concentrations of products and reactants using Le Chatelier's.
by ABombino_2J
Sun Jan 26, 2020 11:07 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE
Replies: 20
Views: 173

Re: ICE

You may also need to use an ICE table when asked for the PH. Indirectly they are asking for the [H3O+] concentration to find the PH.
by ABombino_2J
Sun Jan 26, 2020 11:03 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: delta s
Replies: 5
Views: 42

Re: delta s

No delta S is entropy which measures change in disorder of a system. Delta H is enthalpy which measures change of heat in a system.
by ABombino_2J
Sun Jan 26, 2020 11:01 pm
Forum: Phase Changes & Related Calculations
Topic: Phase changes
Replies: 8
Views: 73

Re: Phase changes

Phase changes take up a large amount of heat so although heat is being supplied, the temperature does not change until the threshold for the new phase is reached.
by ABombino_2J
Sun Jan 26, 2020 10:58 pm
Forum: Phase Changes & Related Calculations
Topic: Hess's Law
Replies: 8
Views: 61

Re: Hess's Law

Hess' Law essential proves that enthalpy is a state function because you are allowed to add enthalpies without any regard for how the value was obtained.
by ABombino_2J
Sun Jan 26, 2020 10:57 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Percent Ionization
Replies: 12
Views: 74

Re: Percent Ionization

Percent ionization is the x, or [H3O+] concentration divided, by by the initial acid concentration.
by ABombino_2J
Sun Jan 26, 2020 10:56 pm
Forum: Phase Changes & Related Calculations
Topic: Enthalpy of Vaporization and Fusion
Replies: 5
Views: 36

Re: Enthalpy of Vaporization and Fusion

The energy required to turn a liquid into a gas is a lot more than the energy that is required to turn a solid into a liquid.
by ABombino_2J
Fri Jan 10, 2020 11:08 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Pressure's Effect on Equilibrium
Replies: 6
Views: 101

Re: Pressure's Effect on Equilibrium

When an inert gas is added, the concentrations of the products and the reactions are the same because there are the same moles present in the same volume container; therefore, K does not change.
by ABombino_2J
Fri Jan 10, 2020 11:02 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE Table Ratios
Replies: 7
Views: 76

Re: ICE Table Ratios

The ratio does not matter, but using whole number coefficients goes along better with the balanced equation.
by ABombino_2J
Fri Jan 10, 2020 10:58 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Meaning of equilibrium constant
Replies: 5
Views: 65

Re: Meaning of equilibrium constant

When 10^-3<K<10^3, neither the products nor the reactants are significantly favored. However, if K< 1, the reactants are slightly favored and the reaction lies to the left. Also, if K> 1, the products are slightly favored and the reaction lies to the right.
by ABombino_2J
Fri Jan 10, 2020 10:51 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: K vs Q
Replies: 9
Views: 155

Re: K vs Q

When Q is less than K there are more reactants because a larger denominator in [products]/[reactants] will lead to a smaller value Q. Therefore, this reaction will shift to the right to regain equilibrium. When Q is greater than K there are more products because a larger numerator in [products]/[rea...
by ABombino_2J
Fri Jan 10, 2020 10:42 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: predicting effects
Replies: 9
Views: 149

Re: predicting effects

Removing SO3 will lead to increase in not only NO but also SO3 because when the products are removed the reactants are favored, which means the reaction must shift to the left to once again reach equilibrium to accommodate for the higher concentration of the reactants.
by ABombino_2J
Mon Dec 09, 2019 3:50 am
Forum: Bronsted Acids & Bases
Topic: Strong Acids and Bases
Replies: 6
Views: 163

Re: Strong Acids and Bases

Strong acids are HCl, Her, HI, H2SO4, HClO3, HClO4, and HNo3.
The strong bases are group 1 and 2 oxides and hydroxides.
by ABombino_2J
Mon Dec 09, 2019 3:47 am
Forum: Quantum Numbers and The H-Atom
Topic: n, l ,ml, ms
Replies: 13
Views: 512

Re: n, l ,ml, ms

ms tells you if the electron is spin up or spin down. If it is the first time filling the orbital it is spin up. If you need to pair an electron it will be spin down.
by ABombino_2J
Mon Dec 09, 2019 3:45 am
Forum: DeBroglie Equation
Topic: converting from nm to m
Replies: 3
Views: 144

Re: converting from nm to m

You should convert nm to m so that the units cancel with the m in J.
by ABombino_2J
Mon Dec 09, 2019 3:44 am
Forum: Lewis Acids & Bases
Topic: Lewis acid
Replies: 3
Views: 112

Re: Lewis acid

NH4+ cannot accept anymore electrons because its octet is full.
by ABombino_2J
Mon Dec 09, 2019 3:42 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Stronger acid?
Replies: 10
Views: 510

Re: Stronger acid?

HClO2 is the stronger acid because it pulls electrons away from the H-C bonds making them easier to break which results in more H+ ions in solution.
by ABombino_2J
Mon Dec 09, 2019 3:41 am
Forum: Calculating the pH of Salt Solutions
Topic: OH- and H+
Replies: 6
Views: 179

Re: OH- and H+

If there is an acid in solution it will result in H+(H3O+) and if there is a base in solution it will result in OH-.
by ABombino_2J
Mon Dec 09, 2019 3:39 am
Forum: Calculating the pH of Salt Solutions
Topic: pH
Replies: 6
Views: 153

Re: pH

The higher the H3)+ concentration the lower the pH and the higher the pOH. The higher the OH- concentration the higher the pH and the lower the pOH.
by ABombino_2J
Mon Dec 09, 2019 3:36 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent Shape
Replies: 29
Views: 735

Re: Bent Shape

A bent shape can have either 1 or 2 lone pairs.
by ABombino_2J
Mon Dec 09, 2019 3:33 am
Forum: Naming
Topic: "Ferrate"
Replies: 14
Views: 782

Re: "Ferrate"

In this case it would be ferrate because the coordination compound has a negative charge.
by ABombino_2J
Mon Dec 09, 2019 3:32 am
Forum: Biological Examples
Topic: Myoglobin
Replies: 4
Views: 204

Re: Myoglobin

Myoglobin has the biological capacity to transport 1 single Oxygen molecule.
by ABombino_2J
Wed Nov 27, 2019 12:14 am
Forum: Naming
Topic: Oxidation
Replies: 3
Views: 57

Re: Oxidation

To find the oxidation, take the charge of the one of the atoms you know for sure. O is always -2 and H is always +1. Essentially, take what you know and find the charges of the other atoms by adding or subtracting it to the charge of the molecule.
by ABombino_2J
Wed Nov 27, 2019 12:08 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: How do you know is an acid is strong or weak?
Replies: 6
Views: 81

Re: How do you know is an acid is strong or weak?

The stronger the acid the more it will dissociate in water. The weaker the acid the less it will dissociate in water
by ABombino_2J
Wed Nov 27, 2019 12:02 am
Forum: Naming
Topic: Alphabetical Order
Replies: 6
Views: 63

Re: Alphabetical Order

Do all the ligands in alphabetical order not paying attention to the greek prefixes then put the central metal atom. All of these must be in the coordination sphere. Following the items within the coordination sphere, put the other ions and molecules.
by ABombino_2J
Tue Nov 26, 2019 11:58 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polarity and dipole moments
Replies: 8
Views: 110

Re: Polarity and dipole moments

A dipole cancels when a molecule has no lone pairs and the same attachments. It also will cancel when the net dipole moments cancel when they are facing the opposite directions. In addition, it is important to know that 2-3 linear geometry and square planar are non-polar when they have the same atta...
by ABombino_2J
Tue Nov 26, 2019 11:54 pm
Forum: Amphoteric Compounds
Topic: Amphoteric
Replies: 8
Views: 102

Re: Amphoteric

If you look at Be, Al, Ga, Sn, Pb, and Sb they form a rough diagonal line on the periodic table
by ABombino_2J
Sun Nov 24, 2019 9:34 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Numbers
Replies: 4
Views: 51

Re: Coordination Numbers

The coordination number is the amount of atoms or molecules attached directly to the central atom.
by ABombino_2J
Sun Nov 24, 2019 9:26 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Transition Metals
Replies: 7
Views: 82

Re: Transition Metals

Because the transition metals are all good Lewis acids, they can all form coordination compounds, but I'm pretty sure he said we only need to concern ourselves with the first row.
by ABombino_2J
Sun Nov 24, 2019 9:19 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Sphere
Replies: 5
Views: 77

Re: Coordination Sphere

The coordination sphere is the sphere around the molecules and ions attached to the transition metal atom. The ligands need to be in the sphere because ligands are the ions attached to the transition metals. Anything within the "[]" is inside the coordination sphere
by ABombino_2J
Sun Nov 24, 2019 9:12 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: H3O+
Replies: 11
Views: 6426

Re: H3O+

H3O+ is has an electron arrangement tetrahedral because there are 4 regions of electron density. However, the shape of H3O+ is trigonal planar because there are 3 bonds and 1 lone pair in H3O+. Be sure when looking at a molecule that you differentiate whether or not you are looking for shape or elec...
by ABombino_2J
Sun Nov 24, 2019 9:09 pm
Forum: Sigma & Pi Bonds
Topic: sigma and pi bonds
Replies: 19
Views: 438

Re: sigma and pi bonds

Yes. All single bonds are sigma bonds. As you add an extra bond, you add a single pi bond to the sigma bond, so a double bond is sigma and pi and a triple bond is a sigma with 2 pis.
by ABombino_2J
Thu Nov 14, 2019 3:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VESPR Model of H2O
Replies: 12
Views: 205

Re: VESPR Model of H2O

H20 has a bent shape because it has 2 lone pairs and 2 single bonds. When trying to determine shape, count all the bonding regions and lone pairs. I assume we will learn about this in class on Friday.
by ABombino_2J
Thu Nov 14, 2019 3:28 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape Name
Replies: 17
Views: 273

Re: Molecular Shape Name

Yes, you should know the shape names as well as the bonding angles. These are easiest to memorize when you look at them in terms of total bonding regions as opposed to individually. You do not need to know how to draw the structure in 3d space, only the lewis structures; 3d will be reserved for orga...
by ABombino_2J
Thu Nov 14, 2019 3:19 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Methane VSEPR
Replies: 7
Views: 81

Re: Methane VSEPR

In 3-d Space when all the H atoms are equally spaced from C and when all the H atoms are as far apart as possible, the angle of the H-C-H bonds are approximately 109.5 degrees.
by ABombino_2J
Thu Nov 14, 2019 3:09 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Electrons
Replies: 9
Views: 104

Re: Electrons

When electrons are close together, their negative charges repel each other which leads to a more unstable molecule. When the electrons are father apart, the electron electron repulsion is much less and in some cases 0.
by ABombino_2J
Thu Nov 14, 2019 3:04 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Resonance VSEPR
Replies: 6
Views: 67

Re: Resonance VSEPR

When trying to determine shape, only pay attention to bonding regions, not the amount of bonds.
by ABombino_2J
Fri Nov 01, 2019 12:44 pm
Forum: Lewis Structures
Topic: Charges on Lewis Structures
Replies: 7
Views: 96

Re: Charges on Lewis Structures

For a molecule with a +1 charge such as ammonium, NH4+, you would subtract one e- from the valence e- so the total valence e- would 8. For a molecule with a -1 share like sulfate, SO4^2-, you would add 2 extra valence e-. The result is 32. To draw the lewis structure, just be sure to satisfy the amo...
by ABombino_2J
Fri Nov 01, 2019 12:35 pm
Forum: Lewis Structures
Topic: Lone Pairs
Replies: 10
Views: 98

Re: Lone Pairs

Lone pairs are pairs of electrons that are not shared with other elements. They are represented by dots around an element. To find the amount of lone pairs, count the number of dots and divide that number by 2.
by ABombino_2J
Fri Nov 01, 2019 12:29 pm
Forum: Bond Lengths & Energies
Topic: Single bond vs double bond
Replies: 14
Views: 286

Re: Single bond vs double bond

The double bonds are shorter than the single bonds because the extra e- creates more attractions between 2 elements. However, for benzene there are not true single or double bonds. Benzene actually has delocalized bonds, so rather than drawing a hexagon with alternating double bonds, the actually st...
by ABombino_2J
Fri Nov 01, 2019 12:17 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Writing electron configuration
Replies: 7
Views: 111

Re: Writing electron configuration

Yes, for Ca the electron configuration would en with 4s^2. For Ca^2+, the electron configuration would end with 3p^6.
by ABombino_2J
Fri Nov 01, 2019 12:12 pm
Forum: Bond Lengths & Energies
Topic: bond lengths
Replies: 10
Views: 234

Re: bond lengths

Bond dissociation is the energy required to break a chemical bond. For example, to break an H--H bond, the bond dissociation energy is 436D.
by ABombino_2J
Fri Nov 01, 2019 12:04 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Writing electron configuration
Replies: 7
Views: 111

Re: Writing electron configuration

Whenever you are writing an electron configuration the orbital with the lower n should come first.
by ABombino_2J
Sun Oct 27, 2019 7:32 pm
Forum: Lewis Structures
Topic: Lewis Structure
Replies: 5
Views: 67

Re: Lewis Structure

The 2 double bonds on the sulfate atom bring the formal charge of sulfate to 0. It is more important to have a lower formal charge on the central atom because it has a lower electron affinity.
by ABombino_2J
Sun Oct 27, 2019 7:30 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: p-orbitals
Replies: 11
Views: 124

Re: p-orbitals

The Px, Py, Pz should only be used when showing if the orbitals are full.
by ABombino_2J
Sun Oct 27, 2019 7:25 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 5
Views: 78

Re: Formal Charge

A single bond is counted as one electron although a single bond has a value of 2 electrons because 1 electron goes to one atom and the other electron goes to the other atom.
by ABombino_2J
Sun Oct 27, 2019 6:49 pm
Forum: Properties of Electrons
Topic: Electron removal
Replies: 11
Views: 161

Re: Electron removal

The electrons closer to the nucleus experience a stronger attraction and shield the outer electrons from receiving the same type of attraction.
by ABombino_2J
Sun Oct 27, 2019 6:37 pm
Forum: Ionic & Covalent Bonds
Topic: Valence Electrons
Replies: 16
Views: 229

Re: Valence Electrons

The valence electrons are electrons in the outer shell. If n=3, all of the electrons in that shell are the valance electrons.
by ABombino_2J
Sun Oct 20, 2019 9:58 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Pauli Exclusion Prinicple
Replies: 3
Views: 63

Re: Pauli Exclusion Prinicple

The Pauli Exclusion Principle essentially means that there cannot be more than 1 quantum number per election because, even if they share the same subshell, they will have different spin. If more than 2 electrons were to exist in an orbital they would have the same quantum numbers.
by ABombino_2J
Sun Oct 20, 2019 9:53 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron configurations of ions
Replies: 4
Views: 39

Re: Electron configurations of ions

If the ion is positive, electrons must be taken away from the electron configuration because electrons have a negative charge. When the ion is negative, electrons must be added to the next available subshells.
by ABombino_2J
Sun Oct 20, 2019 9:49 pm
Forum: Quantum Numbers and The H-Atom
Topic: Quantum Number
Replies: 4
Views: 64

Re: Quantum Number

You should not have to memorize anything since it can all be found on the periodic table.
by ABombino_2J
Sun Oct 20, 2019 9:48 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Ground State
Replies: 5
Views: 83

Re: Ground State

Ground state means that all the electrons are in the lowest possible energy levels. An excited state is when the electrons exist in a higher energy level.
by ABombino_2J
Sun Oct 20, 2019 9:41 pm
Forum: Properties of Electrons
Topic: Electron Configuration
Replies: 4
Views: 82

Re: Electron Configuration

The 3d orbital has less energy than the 4s orbital so it must come before because electron configurations are written in order based on amounts of energy.
by ABombino_2J
Sun Oct 13, 2019 5:53 pm
Forum: DeBroglie Equation
Topic: Wavelength
Replies: 6
Views: 84

Re: Wavelength

The smallest detectable wavelength is a gamma ray at 10^-14 meters. Professor Lavelle said anything smaller than 10^-15 meters is irrelevant and we should consider it to have an undetectable wavelength.
by ABombino_2J
Sun Oct 13, 2019 5:34 pm
Forum: SI Units, Unit Conversions
Topic: Unit conversion
Replies: 15
Views: 529

Re: Unit conversion

You need to use stoichiometry. (Unit A)(Unit B/Unit A). This will work for any unit so long as they are similar. For example: meters with millimeters or grams with kilograms.
by ABombino_2J
Sun Oct 13, 2019 5:21 pm
Forum: Balancing Chemical Reactions
Topic: Combustion
Replies: 17
Views: 585

Re: Combustion

Combustion, or burning, occurs whenever a hydrocarbon interacts with Oxygen. The products are Carbon dioxide and Water. The more oxygen present the more successful the combustion will be.
by ABombino_2J
Sun Oct 13, 2019 5:15 pm
Forum: Significant Figures
Topic: When to apply Sig Figs
Replies: 6
Views: 195

Re: When to apply Sig Figs

You should apply sig figs at the end of the calculation so that you do not get a rounding error for your final answer. It will be more accurate if you wait until the end.
by ABombino_2J
Sun Oct 13, 2019 5:11 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Electron Configuration
Replies: 5
Views: 100

Re: Electron Configuration

You need to memorize it based on where the element shows up on the periodic table. The first S orbital begins with 1. The first P orbital starts with 2. The first D orbital starts with 3. The first F orbital starts with 4. For each row you go down on the periodic table these numbers increase by 1.
by ABombino_2J
Fri Oct 04, 2019 1:19 am
Forum: Limiting Reactant Calculations
Topic: Percent or theoretical yield
Replies: 14
Views: 727

Re: Percent or theoretical yield

The theoretical yield is calculated using stoichiometry to find the ideal mass of a product under ideal lab conditions. The percent yield shows how accurate the actual yield is in comparison to the theoretical yield. The percent yield is calculated using the following equation: percent yield= (actua...
by ABombino_2J
Fri Oct 04, 2019 1:03 am
Forum: SI Units, Unit Conversions
Topic: scientific notation
Replies: 7
Views: 80

Re: scientific notation

Scientific notation should be used to provide a more simplified view of an extreme number. .000006 is difficult to understand quickly so 6.0 x 10^-6 is used so that scientists can understand the number and it’s ramifications more easily.
by ABombino_2J
Fri Oct 04, 2019 12:37 am
Forum: Molarity, Solutions, Dilutions
Topic: Converting Before or After?
Replies: 10
Views: 153

Re: Converting Before or After?

You can have the final units in whichever unit makes the most sense. For example, you would not want a final mass to be 9.8 x 10^-2 kg because you could just say 98g unless it explicitly asks for kg. As you work the problem, you should use whichever units are easiest to use. Grams are usually easies...

Go to advanced search