Search found 60 matches

by Krista Mercado 1B
Sun Mar 10, 2019 12:50 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Study Advice
Replies: 73
Views: 3818

Re: Study Advice

Lyndon and Karen's workshops are usually the most helpful for me.
by Krista Mercado 1B
Sun Mar 10, 2019 12:47 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Bimolecular
Replies: 13
Views: 653

Re: Bimolecular

A bimolecular reaction involves two reactants. This is an example of a second-order reaction.
by Krista Mercado 1B
Sun Mar 10, 2019 12:44 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: k & K
Replies: 18
Views: 799

Re: k & K

The difference is that k is Boltzmann's constant, while K is the equilibrium constant for a given reaction.
by Krista Mercado 1B
Sun Mar 03, 2019 3:17 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: H+, OH-, water
Replies: 9
Views: 290

Re: H+, OH-, water

You would include H+ and OH-, but not H2O
by Krista Mercado 1B
Sun Mar 03, 2019 3:13 pm
Forum: Balancing Redox Reactions
Topic: oxidizing agent and reducing agent
Replies: 15
Views: 502

Re: oxidizing agent and reducing agent

The compound that is reduced is considered the oxidizing agent. The compound that is oxidized is the reducing agent.
by Krista Mercado 1B
Sun Mar 03, 2019 3:12 pm
Forum: Balancing Redox Reactions
Topic: Creating a cell diagram
Replies: 8
Views: 283

Re: Creating a cell diagram

You would include H+ but not H2O
by Krista Mercado 1B
Sat Feb 23, 2019 5:00 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: delta S= q(rev)/ T
Replies: 5
Views: 323

Re: delta S= q(rev)/ T

This equation is used to find the change in entropy for isothermal reversible reactions.
by Krista Mercado 1B
Sat Feb 23, 2019 4:51 am
Forum: Balancing Redox Reactions
Topic: difference between oxidation and reduction
Replies: 8
Views: 255

Re: difference between oxidation and reduction

When the charge changes from +2 to +4, that means the atom has lost 2 electrons. Since there is a loss of electrons, this is an example of an oxidation reaction.
by Krista Mercado 1B
Sat Feb 23, 2019 4:49 am
Forum: Balancing Redox Reactions
Topic: Galcanic cell
Replies: 3
Views: 106

Re: Galcanic cell

Galvanic cell is just another name for a voltaic cell.
by Krista Mercado 1B
Tue Feb 19, 2019 1:40 am
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Microstates
Replies: 7
Views: 500

Re: Microstates

The equation to find entropy is S=kblnW, where W=(# of microstates)^(# of molecules)
by Krista Mercado 1B
Tue Feb 19, 2019 1:36 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Cup of Tea
Replies: 17
Views: 741

Re: Cup of Tea

It can exchange both matter and energy with its surroundings.
by Krista Mercado 1B
Tue Feb 19, 2019 1:33 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Extensive vs Intensive
Replies: 7
Views: 419

Re: Extensive vs Intensive

Extensive properties depend on the amount of matter being measured. On the other hand, intensive properties do not depend on the amount of substance present.
by Krista Mercado 1B
Sat Feb 09, 2019 8:55 pm
Forum: Calculating Work of Expansion
Topic: Work
Replies: 5
Views: 198

Re: Work

Danny Elias Dis 1E wrote:Is this situation also the case where deltaU = q?

Yes, because ΔU = q+w, and if w = 0, then ΔU = q+0 = q.
by Krista Mercado 1B
Sat Feb 09, 2019 8:51 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: U
Replies: 7
Views: 202

Re: U

This mean that internal energy depends only on the current state of the system and is independent of how that state was prepared. Other examples of state functions are pressure, volume, temperature, and density.
by Krista Mercado 1B
Sat Feb 09, 2019 8:39 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: q= -w
Replies: 8
Views: 226

Re: q= -w

This is the case when the change in internal energy is 0
by Krista Mercado 1B
Wed Jan 30, 2019 10:57 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: increasing pressure, what happens to concentration?
Replies: 10
Views: 506

Re: increasing pressure, what happens to concentration?

Increasing pressure will cause the reaction to proceed towards the side with less moles of gas.
by Krista Mercado 1B
Wed Jan 30, 2019 10:49 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: closed vs isolated
Replies: 14
Views: 337

Re: closed vs isolated

A closed system has a fixed amount of matter, but can exchange energy with its surroundings. An isolated system there cannot be transfer of energy or matter between a system and its surroundings. An open system can freely exchange matter and energy with its surroundings.
by Krista Mercado 1B
Wed Jan 30, 2019 10:37 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: ICE
Replies: 19
Views: 592

Re: ICE

E stands for equilibrium concentration.
by Krista Mercado 1B
Wed Jan 30, 2019 10:36 pm
Forum: Ideal Gases
Topic: pH and pOH
Replies: 18
Views: 872

Re: pH and pOH

The question will tell you which to solve for.
by Krista Mercado 1B
Wed Jan 30, 2019 10:29 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Q VS. K
Replies: 13
Views: 775

Re: Q VS. K

Q and K are calculated the same way. If Q<K, then the reaction will tend to proceed towards the products. If Q>K, then the reaction will proceed towards the reactants.
by Krista Mercado 1B
Thu Jan 24, 2019 11:59 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Neutral solutions
Replies: 2
Views: 101

Re: Neutral solutions

I think the solution is considered neutral if [H3O+] is equal to 10^-7. If it is less than that, then it is considered a basic solution.
by Krista Mercado 1B
Sun Jan 20, 2019 10:57 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Reaction Quotient
Replies: 3
Views: 412

Re: Reaction Quotient

By comparing Q to K, it will tell you whether the reaction will proceed forward, backward, or is already at equilibrium If Q = K, then the reaction is at equilibrium If Q < K, then the reaction will favor the products (proceeds forward) If Q > K, then the reaction will favor the reactants (proceeds ...
by Krista Mercado 1B
Sun Jan 20, 2019 10:50 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Reaction Quotient
Replies: 3
Views: 347

Re: Reaction Quotient

The reaction quotient, Q, tells you the ratio of products to reactants at any given instant. The equilibrium constant, K, gives you the ratio of products to reactants when the reaction is at equilibrium.
by Krista Mercado 1B
Sun Jan 20, 2019 10:43 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Solids and Liquids with the Reaction Quotient
Replies: 3
Views: 164

Re: Solids and Liquids with the Reaction Quotient

No, solids and liquids are not included in Q or K.
by Krista Mercado 1B
Thu Jan 10, 2019 10:49 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Effects on Equilibrium
Replies: 2
Views: 106

Re: Effects on Equilibrium

It's important to note that different initial concentrations of a reaction does not affect the equilibrium constant.
by Krista Mercado 1B
Thu Jan 10, 2019 10:35 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Calculating K
Replies: 3
Views: 58

Re: Calculating K

We can use either partial pressure or concentration to calculate K, but partial pressure can only be used in gas phase reactions.
by Krista Mercado 1B
Thu Jan 10, 2019 10:32 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Writing Equilibrium Expressions
Replies: 3
Views: 112

Re: Writing Equilibrium Expressions

Yes, brackets are used specifically in equilibrium expressions to indicate the concentration of a certain substance.
by Krista Mercado 1B
Sun Dec 09, 2018 4:17 pm
Forum: Limiting Reactant Calculations
Topic: moles of reagant
Replies: 4
Views: 457

Re: moles of reagant

You would have to convert the amount of grams of the limiting reactant to moles, then compare the ratios of the reactants in the balanced equation to figure out how many moles of the reactant are required.
by Krista Mercado 1B
Sun Dec 09, 2018 4:13 pm
Forum: Amphoteric Compounds
Topic: Examples
Replies: 5
Views: 391

Examples

What are some examples of amphoteric compounds?
by Krista Mercado 1B
Sat Dec 08, 2018 5:11 pm
Forum: Calculating the pH of Salt Solutions
Topic: pH formula?
Replies: 21
Views: 735

Re: pH formula?

The pH formula is pH = -log[H+]. I don't think we need to know how it is derived.
by Krista Mercado 1B
Sat Dec 08, 2018 4:57 pm
Forum: Naming
Topic: Do we have to memorize some of the ligand names?
Replies: 3
Views: 156

Re: Do we have to memorize some of the ligand names?

I think we need to memorize the charges of the ligands as well.
by Krista Mercado 1B
Sat Dec 08, 2018 4:55 pm
Forum: Administrative Questions and Class Announcements
Topic: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
Replies: 118
Views: 11191

Re: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]

Thank you so much for the final review and practice problems!
by Krista Mercado 1B
Fri Nov 30, 2018 4:18 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Acid vs base [ENDORSED]
Replies: 15
Views: 554

Re: Acid vs base [ENDORSED]

A Lewis acid is an electron acceptor and a Lewis base is an electron donor.
by Krista Mercado 1B
Fri Nov 30, 2018 4:16 pm
Forum: Lewis Acids & Bases
Topic: Bronsted Acids & Bases vs. Lewis Acid & Bases
Replies: 3
Views: 108

Re: Bronsted Acids & Bases vs. Lewis Acid & Bases

A Lewis acid is an electron acceptor, and a Lewis base is an electron donor. On the other hand, a Bronsted acid is a proton donor, and a Bronsted base is a proton acceptor. The definition that you use just depends on whether you're focusing on the transfer of electrons or protons.
by Krista Mercado 1B
Fri Nov 30, 2018 4:12 pm
Forum: Amphoteric Compounds
Topic: Amphoteric Oxides
Replies: 4
Views: 416

Re: Amphoteric Oxides

I don't know if we'll have to remember all of them, but Dr. Lavelle said that there is a diagonal band of amphoteric oxides, between the metal oxides and nonmetal oxides, that closely matches the diagonal band of metalloids.
by Krista Mercado 1B
Sun Nov 25, 2018 3:00 am
Forum: Dipole Moments
Topic: Dipole Moment
Replies: 2
Views: 153

Re: Dipole Moment

Greater polarity between molecules leads to a stronger dipole moment. This means that the larger the difference in electronegativity of the bonded atoms, the larger the dipole moment.
by Krista Mercado 1B
Sun Nov 25, 2018 2:56 am
Forum: Sigma & Pi Bonds
Topic: Double Bonds
Replies: 9
Views: 556

Re: Double Bonds

Yes. With multiple bonds, there is only one sigma-bond and each additional bond is a pi-bond. For a double bond there is one sigma-bond and one pi-bond.
by Krista Mercado 1B
Sun Nov 25, 2018 2:46 am
Forum: Sigma & Pi Bonds
Topic: Which bond would break first.
Replies: 15
Views: 958

Re: Which bond would break first.

The pi-bond would break first since pi-bonds are weaker than sigma-bonds. This is because the side-by-side overlap in a pi-bond is smaller and weaker than the end-to-end overlap in a sigma bond.
by Krista Mercado 1B
Sun Nov 25, 2018 2:43 am
Forum: Sigma & Pi Bonds
Topic: Sigma and pi bonds and hybridization
Replies: 2
Views: 239

Sigma and pi bonds and hybridization

What is the relationship between sigma/pi bonds and hybridization?
by Krista Mercado 1B
Sun Nov 18, 2018 7:52 pm
Forum: Dipole Moments
Topic: Difference between dipole and london forces?
Replies: 5
Views: 214

Re: Difference between dipole and london forces?

Dipole-dipole forces occur between polar molecules when the positive end of one is attracted to the negative end of the other and vice-versa.
London forces occur between all types of molecules (polar and non-polar) and are weaker than dipole-dipole forces.
by Krista Mercado 1B
Sun Nov 18, 2018 7:48 pm
Forum: Sigma & Pi Bonds
Topic: usage of sigma/pi
Replies: 6
Views: 266

Re: usage of sigma/pi

RoopshaChatterjee 1G wrote:Can the sigma/pi bonds also be used to determine the structure of the molecule?

Sigma and pi bonds can't be used to determine the structure of a molecule since they do not affect shape or structure.
by Krista Mercado 1B
Sun Nov 18, 2018 7:43 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pairs
Replies: 3
Views: 138

Lone Pairs

When there is a lone pair, why does this make the bond angle smaller? Also, how do you determine how much smaller the bond angle will be?
by Krista Mercado 1B
Thu Nov 08, 2018 11:24 am
Forum: Bond Lengths & Energies
Topic: MIDTERM Bond Length Question
Replies: 15
Views: 534

Re: MIDTERM Bond Length Question

Since a resonance hybrid is a blend of Lewis structures, all the bond lengths are the same. Thus, even though there are both single and double bonds in the resonance structure, all of the bond lengths will be the average between the different bond lengths of the structure. For this specific question...
by Krista Mercado 1B
Thu Nov 08, 2018 11:12 am
Forum: Resonance Structures
Topic: Resonance Structures
Replies: 3
Views: 177

Resonance Structures

How can you determine if a certain compound requires a resonance structure?
by Krista Mercado 1B
Tue Nov 06, 2018 1:04 pm
Forum: Ionic & Covalent Bonds
Topic: Greater Ionic Character? [ENDORSED]
Replies: 3
Views: 219

Re: Greater Ionic Character? [ENDORSED]

You can determine this by looking at the difference in the electronegativity of the atoms involved in the bond. The bond with a greater difference in electronegativity has a greater ionic character.
by Krista Mercado 1B
Sat Nov 03, 2018 11:46 pm
Forum: Octet Exceptions
Topic: Copper
Replies: 10
Views: 375

Copper

Why is the ground state electron configuration of copper [Ar]3d^(10)4s^(1) and not [Ar]3d^(9)4s^(2)?
by Krista Mercado 1B
Sat Nov 03, 2018 11:42 pm
Forum: Resonance Structures
Topic: Resonance [ENDORSED]
Replies: 2
Views: 141

Resonance [ENDORSED]

How does resonance help to stabilize the molecule?
by Krista Mercado 1B
Sat Nov 03, 2018 11:40 pm
Forum: Ionic & Covalent Bonds
Topic: Homework Problem 3.19
Replies: 2
Views: 131

Homework Problem 3.19

Give the ground-state electron configuration and number of unpaired electrons expected for each of the following ions:
(a) Sb3
(b) Sn4
How do you find the number of unpaired electrons?
by Krista Mercado 1B
Sun Oct 28, 2018 12:38 am
Forum: Trends in The Periodic Table
Topic: Ionization Energy and Electron Affinity
Replies: 9
Views: 947

Re: Ionization Energy and Electron Affinity

Why are electrons that are further away from the nucleus easier to remove? The nucleus has a positive charge, which attracts negatively charged electrons. If electrons are farther away from the nucleus, this positive nuclear charge is weaker, so the electrons aren't pulled as tightly towards the nu...
by Krista Mercado 1B
Wed Oct 24, 2018 10:50 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Subshells/Orbitals
Replies: 5
Views: 272

Re: Subshells/Orbitals

I don't think we need to know the specific shapes of the f orbitals, we just need to know that it has 7 different orbitals which hold a total of 14 electrons.
by Krista Mercado 1B
Wed Oct 24, 2018 10:44 pm
Forum: Quantum Numbers and The H-Atom
Topic: Electron Configuration Order
Replies: 2
Views: 64

Re: Electron Configuration Order

This is because the 4s orbital is slightly closer to the nucleus, and thus has a slightly lower energy than the 3d orbital. This means that the 4s orbital will be filled before the 3d orbital. This concept applies to the elements Calcium (Ca) and Potassium (K).
by Krista Mercado 1B
Thu Oct 18, 2018 2:28 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Nodes/ Nodals
Replies: 2
Views: 85

Re: Nodes/ Nodals

A node is where the probability of finding an electron is zero.
by Krista Mercado 1B
Thu Oct 18, 2018 2:26 pm
Forum: *Shrodinger Equation
Topic: Schrodinger Equation
Replies: 2
Views: 54

Schrodinger Equation

I know we do not have to know how to use the Schrodinger Equation in calculations, but what specifically do we need to know about the equation?
by Krista Mercado 1B
Tue Oct 16, 2018 11:13 am
Forum: Photoelectric Effect
Topic: Spectroscopic series
Replies: 2
Views: 181

Re: Spectroscopic series

I agree with Emily, I think the Balmer series and the Lyman series are the two that we need to know. The Balmer series corresponds with the visible region of the spectrum, and electrons come to rest at energy level n=2. The Lyman series corresponds with the ultraviolet region, and electrons come to ...
by Krista Mercado 1B
Fri Oct 12, 2018 2:16 pm
Forum: DeBroglie Equation
Topic: Measurable wavelengths
Replies: 3
Views: 96

Re: Measurable wavelengths

In the 12-1 lecture Dr. Lavelle also said wavelike properties are measurable when the De Brogile wavelength is at least (some value)x10^-18.
by Krista Mercado 1B
Fri Oct 12, 2018 2:11 pm
Forum: Properties of Electrons
Topic: Energy emitted by electrons
Replies: 6
Views: 218

Re: Energy emitted by electrons

The energy that was lost is released as electromagnetic radiation, which is why the change in energy is negative.
by Krista Mercado 1B
Fri Oct 12, 2018 2:05 pm
Forum: DeBroglie Equation
Topic: Question about diffraction patterns
Replies: 2
Views: 129

Re: Question about diffraction patterns

Constructive interference is when two waves meet in a way that their crests line up. This results in a wave of a higher amplitude. On the other hand, destructive interference is when the crest of one wave meets with the trough of the other. This results in a wave of lower amplitude.
by Krista Mercado 1B
Thu Oct 04, 2018 4:15 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Molar Masses
Replies: 9
Views: 251

Re: Molar Masses

I remember Dr. Lavelle saying that we will be given a periodic table for the test, and we can use that to calculate the molar mass of the elements and compounds.
by Krista Mercado 1B
Wed Oct 03, 2018 5:23 pm
Forum: Significant Figures
Topic: Significant Figures
Replies: 3
Views: 140

Significant Figures

When should we apply the rules of significant figures? Do we use them throughout the problem or just for the final answer?
by Krista Mercado 1B
Tue Oct 02, 2018 3:19 pm
Forum: Balancing Chemical Reactions
Topic: Net number of molecules
Replies: 3
Views: 115

Net number of molecules

How do you calculate the net number of moles produced in a balanced chemical reaction?

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