Search found 60 matches

by 505211599
Sun Mar 17, 2019 11:58 pm
Forum: *Enzyme Kinetics
Topic: How do you tell if something is a catalyst vs an intermediate?
Replies: 13
Views: 546

Re: How do you tell if something is a catalyst vs an intermediate?

Catalyst shows up in products and reactants but intermediated are used during the course of reaction.
by 505211599
Sun Mar 17, 2019 11:58 pm
Forum: Calculating Work of Expansion
Topic: Work in a System
Replies: 4
Views: 209

Re: Work in a System

Work is 0 when volume is constant.
by 505211599
Sun Mar 17, 2019 11:57 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Le Chatlier Principle
Replies: 7
Views: 751

Re: Le Chatlier Principle

Adding a catalysts has no effect on the product or reactant, only speeds up the rate of reaction
by 505211599
Sun Mar 10, 2019 11:45 pm
Forum: Zero Order Reactions
Topic: Zero order reactions
Replies: 4
Views: 74

Re: Zero order reactions

It would make sense that the 0 order reaction is most common because it takes place when concentration of reactants is very high.
by 505211599
Sun Mar 10, 2019 11:44 pm
Forum: Administrative Questions and Class Announcements
Topic: Final
Replies: 18
Views: 522

Re: Final

I think the newer material will be focused on more.
by 505211599
Sun Mar 10, 2019 11:38 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Test 2
Replies: 12
Views: 227

Re: Test 2

Delta G is negative because the reaction is exergonic.
by 505211599
Sun Mar 03, 2019 9:47 pm
Forum: Balancing Redox Reactions
Topic: Acidic vs basic solutions
Replies: 10
Views: 170

Re: Acidic vs basic solutions

For acidic solutions you balance the hyrdrogen by adding H+ and for basic solutions you balance the hydrogen by adding OH-.
by 505211599
Sun Mar 03, 2019 9:41 pm
Forum: Van't Hoff Equation
Topic: Van't Hoff use
Replies: 13
Views: 452

Re: Van't Hoff use

You use Vant Hoff when you are trying to find how K changes as temperature changes.
by 505211599
Sun Feb 24, 2019 10:22 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Spontaneous?
Replies: 13
Views: 187

Re: Spontaneous?

You can only know for sure if a process is spontaneous if delta G is negative.
by 505211599
Sun Feb 24, 2019 10:21 pm
Forum: Balancing Redox Reactions
Topic: Reducing and Oxidizing Agents
Replies: 3
Views: 76

Re: Reducing and Oxidizing Agents

A reactant can be both a reducing and oxidizing agent when it is used in forming products with different oxidation states.
by 505211599
Sun Feb 24, 2019 10:19 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Finding n in Delta G = -nFE
Replies: 3
Views: 83

Re: Finding n in Delta G = -nFE

N is the number of moles of electrons transferred during the redox reaction. You will usually find it when writing half reactions.
by 505211599
Sun Feb 17, 2019 6:59 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Delta G=0
Replies: 1
Views: 35

Re: Delta G=0

the delta G is usually 0 if the reaction is in a state of equilibrium.
by 505211599
Sun Feb 17, 2019 6:57 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibb's Free energy
Replies: 4
Views: 101

Re: Gibb's Free energy

delta g represents the spontaneity, so if it is negative it will be spontaneous and if positive it will be non-spontaneous.
by 505211599
Sun Feb 17, 2019 6:52 pm
Forum: *Free Energy of Activation vs Activation Energy
Topic: Spontaneous reactions
Replies: 7
Views: 1063

Re: Spontaneous reactions

an exothermic reaction is usually spontaneous but if there is a large enough decrease in entropy, the gibb's free energy can be positive, thus making the reaction non-spontaneous.
by 505211599
Sun Feb 10, 2019 10:24 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Occupying positions
Replies: 2
Views: 57

Re: Occupying positions

I think it means that entropy is greater for the liquid form.
by 505211599
Sun Feb 10, 2019 10:21 pm
Forum: Calculating Work of Expansion
Topic: Reversible Expansion
Replies: 3
Views: 65

Re: Reversible Expansion

If the system is isolated, then the reversible expansion wil result in a lower internal energy.
by 505211599
Sun Feb 10, 2019 10:09 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Isothermal meaning
Replies: 4
Views: 105

Re: Isothermal meaning

Isothermal means that the temperature will remain constant.
by 505211599
Sun Feb 03, 2019 8:32 pm
Forum: Calculating Work of Expansion
Topic: Units for pressure
Replies: 10
Views: 160

Re: Units for pressure

You would normally use atm or bar as units in your answer.
by 505211599
Sun Feb 03, 2019 8:32 pm
Forum: Calculating Work of Expansion
Topic: Isolated System
Replies: 5
Views: 121

Re: Isolated System

We do not consider the heat of surroundings in an isolated system because there is no energy exchange.
by 505211599
Sun Feb 03, 2019 8:30 pm
Forum: Calculating Work of Expansion
Topic: work done by vs on a system
Replies: 5
Views: 93

Re: work done by vs on a system

Work being done by a system is negative because energy is taken out of the system, while work done on a system is positive because energy is put into the system.
by 505211599
Mon Jan 28, 2019 12:54 am
Forum: Ideal Gases
Topic: pH and pOH
Replies: 18
Views: 506

Re: pH and pOH

The question will tell whether to solve for ph or pOH.
by 505211599
Mon Jan 28, 2019 12:46 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat Capacity
Replies: 8
Views: 142

Re: Heat Capacity

Heat capacity is an extensive property while specific heat is intensive.
by 505211599
Mon Jan 28, 2019 12:44 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Units of Kp
Replies: 9
Views: 410

Re: Units of Kp

It is any unit that can measure pressure such as atm or bar.
by 505211599
Mon Jan 28, 2019 12:41 am
Forum: Phase Changes & Related Calculations
Topic: reversible/irreversible
Replies: 8
Views: 130

Re: reversible/irreversible

A reversible process is one where the system is always at a point of equilibrium whereas the irreversible process is one where the system is not always at equilibrium. Also, reversible processes tend to do more work.
by 505211599
Mon Jan 28, 2019 12:39 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: pKa vs. pH
Replies: 15
Views: 440

Re: pKa vs. pH

The pKa is the -log(Ka) and pH is -log(H+)
by 505211599
Mon Jan 28, 2019 12:36 am
Forum: Phase Changes & Related Calculations
Topic: Phase changes
Replies: 14
Views: 193

Re: Phase changes

You are correct. Phase changes from vapor to gas will be exothermic and the other way around is endothermic.
by 505211599
Sun Jan 20, 2019 11:56 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Is it an acid or a base?
Replies: 8
Views: 180

Re: Is it an acid or a base?

Acids usually donate protons (H+) while bases accept protons.
by 505211599
Sun Jan 20, 2019 11:54 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Changes in Temperature
Replies: 8
Views: 127

Re: Changes in Temperature

If a reaction is endothermic( absorbs energy), a temperature increase will favor the products side. If a reaction is exothermic( gives off energy), a temperature increase will favor the reactants side.
by 505211599
Sun Jan 20, 2019 11:53 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ice table mols/molarity
Replies: 3
Views: 73

Re: ice table mols/molarity

Solving for molarity beforehand will allow you to find the unknown values as opposed to finding moles.
by 505211599
Fri Dec 07, 2018 9:10 pm
Forum: Hybridization
Topic: lone pairs of e-
Replies: 4
Views: 115

Re: lone pairs of e-

You would not need to know the hybridization of lone pairs.
by 505211599
Fri Dec 07, 2018 9:08 pm
Forum: Bronsted Acids & Bases
Topic: Oxoacids
Replies: 2
Views: 67

Re: Oxoacids

An oxoacid is characterized by at least one hydrogen atom bonded to at least one oxygen and a nonmetal.
by 505211599
Fri Dec 07, 2018 9:06 pm
Forum: General Science Questions
Topic: hydrogen bonding
Replies: 3
Views: 275

Re: hydrogen bonding

The hydrogen would have to be attached to F,O, or N.
by 505211599
Sun Dec 02, 2018 11:49 pm
Forum: Amphoteric Compounds
Topic: Amphoteric compounds besides water
Replies: 6
Views: 126

Re: Amphoteric compounds besides water

An amphoteric compound may be able to add an H+ or remove an H+. Compounds like this include HSO4- and H2PO4-.
by 505211599
Sun Dec 02, 2018 11:47 pm
Forum: Hybridization
Topic: Hybridization
Replies: 11
Views: 184

Re: Hybridization

Trigonal planar has 3 regions of electron density so it would be sp2
by 505211599
Sun Dec 02, 2018 11:44 pm
Forum: Bronsted Acids & Bases
Topic: Net Ionic Equations
Replies: 2
Views: 73

Re: Net Ionic Equations

I think net ionics are useful for identifying bronsted acids and bases in a chemical reaction. You can usually identify the charge on the icon by the oxidation state.
by 505211599
Sun Nov 25, 2018 11:50 pm
Forum: Hybridization
Topic: Questions in Chapter
Replies: 5
Views: 111

Re: Questions in Chapter

Knowing the name is not necessary, usually the formula will be given.
by 505211599
Sun Nov 25, 2018 11:49 pm
Forum: Hybridization
Topic: hybridization of BeCl2
Replies: 4
Views: 69

Re: hybridization of BeCl2

BeCl2 has a Lewis structure with 2 electron densities. Therefore the the hybridization is sp.
by 505211599
Sun Nov 25, 2018 11:47 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bonds
Replies: 3
Views: 77

Re: Bonds

Sigma bonds are observed in single bonds but pi bonds are observed in double and triple bonds.
by 505211599
Mon Nov 19, 2018 12:25 am
Forum: Resonance Structures
Topic: Drawing resonance
Replies: 17
Views: 617

Re: Drawing resonance

I think that if a lewis structure has resonance, it would be safe to draw out all possible resonance structures.
by 505211599
Mon Nov 19, 2018 12:23 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: hydrogen bonding
Replies: 11
Views: 240

Re: hydrogen bonding

Hydrogen bonding is the strongest IMF so the energy needed to separate these molecules is higher. Therefore the melting point would be higher.
by 505211599
Mon Nov 19, 2018 12:21 am
Forum: Dipole Moments
Topic: London Force Times
Replies: 3
Views: 104

Re: London Force Times

London forces don’t generally have a set time interval in which the force is active. However, the forces are continuously present between molecules.
by 505211599
Sun Nov 11, 2018 8:21 pm
Forum: Hybridization
Topic: How to Determine
Replies: 12
Views: 336

Re: How to Determine

Hybridization is the result of delocalized electrons from multiple orbitals overlapping to form larger orbitals
by 505211599
Sun Nov 11, 2018 8:18 pm
Forum: Dipole Moments
Topic: Hydrogen Bonds
Replies: 20
Views: 291

Re: Hydrogen Bonds

Hydrogen bonds are the strongest intermolecular force but are still weaker than covalent and ionic bonds.
by 505211599
Sun Nov 11, 2018 8:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: molecular shapes
Replies: 13
Views: 243

Re: molecular shapes

I’m pretty sure we will have to know most of the molecular geometry up to 6 bonds. So that includes bond angle and name.
by 505211599
Fri Nov 02, 2018 11:25 pm
Forum: Quantum Numbers and The H-Atom
Topic: degeneracy of the a 4p orbital
Replies: 9
Views: 522

Re: degeneracy of the a 4p orbital

The degeneracy would be 3 because there are 3 possible orientations for electrons in the p orbital.
by 505211599
Fri Nov 02, 2018 11:21 pm
Forum: Properties of Electrons
Topic: Isoelectronicity
Replies: 3
Views: 312

Re: Isoelectronicity

Isoelectronicity is defined by two or more elements or ions having the same electronic configuration.
by 505211599
Fri Nov 02, 2018 11:19 pm
Forum: Photoelectric Effect
Topic: Test #2 Question #2b
Replies: 4
Views: 361

Re: Test #2 Question #2b

The speed of an ejected electron is not dependent on the intensity of the photon because, as we know, the photoelectric effect theorized that the light is not thought of as a wave propagating through space but instead thought of as quantized packets of energy. Because of this, the energy is dependen...
by 505211599
Fri Oct 26, 2018 11:26 pm
Forum: Resonance Structures
Topic: Resonance Structures
Replies: 5
Views: 170

Re: Resonance Structures

A resonance structure comes into play when there are 2 or more ways of writing out a Lewis structure for a molecule. We lost all structures because we can’t specifically pinpoint one correct structure.
by 505211599
Fri Oct 26, 2018 11:22 pm
Forum: General Science Questions
Topic: Periodic Table
Replies: 16
Views: 516

Re: Periodic Table

I typically try to round to as many decimal places that would allow for an accurate answer but also allows for the limiting significant figure to determine the answer.
by 505211599
Fri Oct 26, 2018 11:20 pm
Forum: Sigma & Pi Bonds
Topic: Sigma v. Pi
Replies: 6
Views: 214

Re: Sigma v. Pi

A sigma bond is a basic covalent bond whereas a public bond whereas a pi bond is a covalent bond between 2 perpendicular orbitals.
by 505211599
Sat Oct 20, 2018 1:44 am
Forum: Properties of Light
Topic: Rydberg formula
Replies: 8
Views: 140

Re: Rydberg formula

It's also important to note that N1 is going to be 1 because the element used is hydrogen. That should clear up any confusion as to missing variables.
by 505211599
Sat Oct 20, 2018 1:09 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Nodes of F Orbital
Replies: 1
Views: 32

Re: Nodes of F Orbital

I believe that the angular nodes number is equal to the angular quantum number
by 505211599
Sat Oct 20, 2018 12:58 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Combustion Problem
Replies: 1
Views: 254

Re: Combustion Problem

To start the problem, you would first calculate how many grams of salicylic acid is contained in the pill. You would do this by multiplying the 1.35g by 0.15. Keep in mind that because this is a percent, the number of significant figures would still be 3. You would then convert the grams of salicyli...
by 505211599
Fri Oct 12, 2018 1:24 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical & Molecular Formulas
Replies: 11
Views: 712

Re: Empirical & Molecular Formulas

Yes they can. If the molar mass of the empirical formula is the same or relatively similar to that of the molecular formula, then the empirical formula is the molecular formula.
by 505211599
Fri Oct 12, 2018 1:23 pm
Forum: Empirical & Molecular Formulas
Topic: Order of Molecules
Replies: 4
Views: 280

Re: Order of Molecules

Usually, if the problem gives the order of the elements, I would just follow that.
by 505211599
Fri Oct 12, 2018 1:19 pm
Forum: Photoelectric Effect
Topic: Variable for frequency
Replies: 6
Views: 107

Re: Variable for frequency

To my knowledge, there aren’t any other variable you could use to differentiate frequency and velocity. You could just curve the v to differentiate it from a normal V.
by 505211599
Fri Oct 05, 2018 2:00 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: MOLARITY
Replies: 17
Views: 633

Re: MOLARITY

Molarity is essentially a quantity used to define the concentration of a substance in solution. It can be used as a conversion factor to determine the moles of a substance or volume of a substance.
by 505211599
Fri Oct 05, 2018 1:57 pm
Forum: Limiting Reactant Calculations
Topic: M15 problem (6th edition)
Replies: 2
Views: 58

Re: M15 problem (6th edition)

For this problem, you are given the grams of both reactants. You would find the limiting reactant by converting the grams of each substance to the theoretical grams of aluminum chloride. Whichever substance produces the least amount of aluminum chloride would be the limiting reactant. This would als...
by 505211599
Thu Oct 04, 2018 8:37 pm
Forum: Limiting Reactant Calculations
Topic: Limiting reactants [ENDORSED]
Replies: 3
Views: 90

Re: Limiting reactants [ENDORSED]

I wouldn't necessarily say that you can assume that the one reactant would be the limiting reactant because there could be additional details in the problem that would say otherwise. However, you could assume that if all other reactants were in "excess", then the one reactant would be cons...

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