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by MariaJohn1D
Sun Mar 15, 2020 6:46 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Same charge
Replies: 1
Views: 67

Same charge

Sometimes when I write half reactions both species have the same charge? What do I do, how do I know how many electrons have been transferred?
by MariaJohn1D
Sun Mar 15, 2020 6:45 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: insoluble
Replies: 1
Views: 77

insoluble

If the reactant is insoluble, then why would E cell be negative?
by MariaJohn1D
Sun Mar 15, 2020 6:45 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: electrodes
Replies: 3
Views: 115

electrodes

What does it mean by standard potential of an electrode is the standard potential of the cell in which electrodes lies on the right and hydrogen electrodes lies on the left?
by MariaJohn1D
Sun Mar 15, 2020 6:44 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 6M 2
Replies: 2
Views: 87

6M 2

For the equation deltaG= -nFE, why can’t you add up the E’s of both half reaction to get Ecell?
by MariaJohn1D
Sun Mar 15, 2020 6:44 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: nernst
Replies: 2
Views: 93

nernst

When you double the equation why does the G increase the E stay the same?
by MariaJohn1D
Mon Mar 02, 2020 5:20 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L5 b.
Replies: 3
Views: 66

Re: 6L5 b.

You need to use platinum as a metal electrode for both sides since none of the products or reactants are conducting metal solids. I2 is a solid at the anode, but since it is a metal it doesn't count. At the cathode, there are only aqueous ions so you would also need the platinum electrode here to a...
by MariaJohn1D
Mon Mar 02, 2020 5:15 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: 6M.11
Replies: 3
Views: 70

6M.11

Why do we flip the reducing agent in the cell notation for this question?
by MariaJohn1D
Mon Mar 02, 2020 2:21 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L5 b.
Replies: 3
Views: 66

6L5 b.

Why do we use platinum on both sides in this case? Because one side already has a solid product?
by MariaJohn1D
Thu Feb 20, 2020 1:18 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Thermodynamics Outline Second Page [ENDORSED]
Replies: 2
Views: 165

Thermodynamics Outline Second Page [ENDORSED]

For the first bullet point on the second page of the outline, what is the explanation for "why reaction free energy depends on pressure and the equilibrium constant?"
by MariaJohn1D
Mon Jan 27, 2020 3:16 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Expansion of a system
Replies: 8
Views: 544

Re: Expansion of a system

Is compression also a form of work?
by MariaJohn1D
Mon Jan 27, 2020 3:14 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: 4A 1 Part c)
Replies: 5
Views: 87

Re: 4A 1 Part c)

Does the pressure change in a bomb calorimeter?
by MariaJohn1D
Mon Jan 27, 2020 3:10 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Delta U
Replies: 3
Views: 84

Re: Delta U

Delta U is the change in internal energy described by the first law of thermodynamics. The equation for delta u is heat (q) + work (w) = Internal energy ( delta U).
by MariaJohn1D
Mon Jan 27, 2020 3:06 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Constant Pressure and how you get it in a calorimeter
Replies: 3
Views: 66

Re: Constant Pressure and how you get it in a calorimeter

I am still confused about the differences in pressure between the bomb calorimeter and coffee cup calorimeter. Why does the pressure change in a bomb calorimeter if its sealed?
by MariaJohn1D
Mon Jan 27, 2020 3:00 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat Capacity
Replies: 7
Views: 98

Re: Heat Capacity

The book states that "The constant-volume and constant-pressure heat capacities of a solid substance are similar; the same is true of a liquid but not of a gas". Why is this not true for a gas? I'm curious about this as well because in lecture he said you need to specify these different h...
by MariaJohn1D
Mon Jan 27, 2020 2:58 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: bomb calorimeter
Replies: 8
Views: 769

Re: bomb calorimeter

Could this be considered an isolated system because it is insulated?
by MariaJohn1D
Mon Jan 27, 2020 2:55 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Irreversible Expansion
Replies: 4
Views: 69

Re: Irreversible Expansion

I'm still confused about the difference between reversible and irreversible equilibrium. The book gives an example of a piston. Can someone please explain it in the context of that?
by MariaJohn1D
Mon Jan 27, 2020 2:45 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: work
Replies: 5
Views: 62

Re: work

Work is w=-P (pressure) (change in volume) . If the volume is increasing or decreasing change the sign accordingly. Also to convert J times atm to J multiply the value by 101.325 J/ L times atm.
by MariaJohn1D
Mon Jan 27, 2020 2:34 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Homework Question 4A.3
Replies: 2
Views: 89

Re: Homework Question 4A.3

The 7th editon solution manual says 28J.
by MariaJohn1D
Mon Jan 27, 2020 2:30 pm
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student [ENDORSED]
Replies: 221
Views: 115975

Re: Advice from a Medical Student [ENDORSED]

Thank you so much for your words of wisdom!
by MariaJohn1D
Fri Jun 08, 2018 9:53 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8200
Views: 1430718

Re: Post All Chemistry Jokes Here

If avogadro calls tell him to leave his number...
by MariaJohn1D
Fri Jun 08, 2018 9:52 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8200
Views: 1430718

Re: Post All Chemistry Jokes Here

Do I know any jokes about sodium? Na
by MariaJohn1D
Fri Jun 08, 2018 9:51 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8200
Views: 1430718

Re: Post All Chemistry Jokes Here

A covalent bond joke? Thanks for sharing...
by MariaJohn1D
Fri Jun 08, 2018 9:50 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8200
Views: 1430718

Re: Post All Chemistry Jokes Here

Don't tell jokes to noble gases you'll get no reaction.
by MariaJohn1D
Fri Jun 08, 2018 9:50 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8200
Views: 1430718

Re: Post All Chemistry Jokes Here

I tell bad chemistry jokes bc all the good ones Argon...
by MariaJohn1D
Fri Jun 08, 2018 9:49 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8200
Views: 1430718

Re: Post All Chemistry Jokes Here

I like chemistry jokes bc they are funny
He He He
by MariaJohn1D
Fri Jun 08, 2018 9:48 pm
Forum: Resonance Structures
Topic: Contributing to Resonance Structures
Replies: 4
Views: 380

Re: Contributing to Resonance Structures

The molecule with the lowest formal charge is deemed as most stable and that would be the most favorable resonance structure.
by MariaJohn1D
Fri Jun 08, 2018 9:28 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: formal charge and VSEPR
Replies: 8
Views: 481

Re: formal charge and VSEPR

VESPR is used to predict molecular geometry using valence shell electrons
by MariaJohn1D
Fri Jun 08, 2018 9:13 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Isoelectronic
Replies: 14
Views: 864

Re: Isoelectronic

Isoelectronic means that both atoms have the same number of valence electrons. Ex: Na+,F-
by MariaJohn1D
Fri Jun 08, 2018 9:12 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Isoelectronic
Replies: 14
Views: 864

Re: Isoelectronic

Isoelectronic means that both atoms have the same number of valence electrons. Ex: Na+,F-
by MariaJohn1D
Fri Jun 08, 2018 8:54 pm
Forum: Hybridization
Topic: Pi bonds in triple bond
Replies: 17
Views: 864

Re: Pi bonds in triple bond

one sigma bond and 2 pi bonds
by MariaJohn1D
Wed Jun 06, 2018 4:41 pm
Forum: Properties of Light
Topic: Wave and Particle
Replies: 10
Views: 667

Re: Wave and Particle

a single particle of light is called a photon whereas a stream of photons is light
by MariaJohn1D
Wed Jun 06, 2018 4:39 pm
Forum: Bond Lengths & Energies
Topic: unit box
Replies: 3
Views: 310

unit box

What is a unit box?
by MariaJohn1D
Wed Jun 06, 2018 4:36 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Le Chatelier's
Replies: 1
Views: 266

Le Chatelier's

What is the relationship between Le Chatelier's principle and hydrogen molecules?
by MariaJohn1D
Wed Jun 06, 2018 4:34 pm
Forum: Polyprotic Acids & Bases
Topic: oxacids and carboxylic acids
Replies: 5
Views: 594

oxacids and carboxylic acids

What is the difference between oxoacids and carboxylic acids?
by MariaJohn1D
Wed Jun 06, 2018 4:32 pm
Forum: Conjugate Acids & Bases
Topic: conjugate seesaw
Replies: 1
Views: 201

conjugate seesaw

What is meant by conjugate see saw?
by MariaJohn1D
Wed Jun 06, 2018 4:26 pm
Forum: Conjugate Acids & Bases
Topic: pKa [ENDORSED]
Replies: 3
Views: 363

pKa [ENDORSED]

How do you know the pKa?
by MariaJohn1D
Wed Jun 06, 2018 4:25 pm
Forum: Identifying Acidic & Basic Salts
Topic: Identifying strong acids and bases
Replies: 2
Views: 377

Re: Identifying strong acids and bases

What's a binary acid?
by MariaJohn1D
Wed Jun 06, 2018 4:19 pm
Forum: Limiting Reactant Calculations
Topic: Reactant vs. Reagent [ENDORSED]
Replies: 23
Views: 18923

Re: Reactant vs. Reagent [ENDORSED]

They can be used interchangeably, but reagents are not usually solvents
by MariaJohn1D
Thu May 17, 2018 9:32 pm
Forum: Ionic & Covalent Bonds
Topic: Configurations
Replies: 4
Views: 263

Configurations

Why do you remove electrons from the highest energy levels first? Ex: from 5s^2 before 4d^10
by MariaJohn1D
Sun Apr 29, 2018 9:40 pm
Forum: Photoelectric Effect
Topic: increasing frequency/ light intensity
Replies: 5
Views: 392

Re: increasing frequency/ light intensity

Changing the frequency changes the wavelength and changing the number of photons changes the light intensity.
by MariaJohn1D
Sun Apr 29, 2018 9:38 pm
Forum: Trends in The Periodic Table
Topic: Radius
Replies: 6
Views: 456

Re: Radius

In a neutral atom the atomic and ionic radii are the same but if there are cations and anions the electron loses a shell and the ionic radius becomes smaller.
by MariaJohn1D
Sun Apr 29, 2018 7:00 pm
Forum: Properties of Light
Topic: Homework Problem(s) [ENDORSED]
Replies: 6
Views: 325

Re: Homework Problem(s) [ENDORSED]

The masses of these will be given on equation sheet.
by MariaJohn1D
Sun Apr 29, 2018 6:52 pm
Forum: Quantum Numbers and The H-Atom
Topic: What do l and m represent? [ENDORSED]
Replies: 6
Views: 452

Re: What do l and m represent? [ENDORSED]

M represents magnetic momentum and l represents angular momentum
by MariaJohn1D
Sun Apr 29, 2018 6:46 pm
Forum: Quantum Numbers and The H-Atom
Topic: Amount of Electrons [ENDORSED]
Replies: 6
Views: 454

Re: Amount of Electrons [ENDORSED]

These numbers respond to a single electron. Think of it like an ID number each electron has its unique set of quantum numbers.
by MariaJohn1D
Sun Apr 29, 2018 6:32 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Why does 4s fill up before 3d?
Replies: 4
Views: 320

Why does 4s fill up before 3d?

Why does the 4s orbital fill up before 3d orbital other than that it's at a "lower energy level"?
by MariaJohn1D
Sun Apr 29, 2018 6:27 pm
Forum: DeBroglie Equation
Topic: Quanta
Replies: 5
Views: 386

Re: Quanta

Quanta is a small packet of energy such as a photon.
by MariaJohn1D
Sun Apr 29, 2018 6:23 pm
Forum: DeBroglie Equation
Topic: Calculating wavelength of an electron
Replies: 4
Views: 279

Re: Calculating wavelength of an electron

When you know velocity of an electron and need to know wavelength use De Broglie's equation. lambda= h/mv
by MariaJohn1D
Sun Apr 29, 2018 6:19 pm
Forum: *Black Body Radiation
Topic: What is Significant about Black Body Radiation? [ENDORSED]
Replies: 4
Views: 737

Re: What is Significant about Black Body Radiation? [ENDORSED]

Black bodies are hot objects that glow(incandescence) and as the temperature rises and shorter wavelengths. The ultraviolet catastrophe is when energy is transferred in packets(quanta), otherwise there would always be darkness.
by MariaJohn1D
Mon Apr 16, 2018 11:54 am
Forum: Empirical & Molecular Formulas
Topic: Molecular to Empirical [ENDORSED]
Replies: 12
Views: 837

Re: Molecular to Empirical [ENDORSED]

To go from the molecular formula to the empirical formula you should divide by the greatest common denominator. Please keep in mind that the molecular and empirical formula can be the same.

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