Search found 78 matches

by AMahadi
Thu Feb 13, 2020 3:10 pm
Forum: Phase Changes & Related Calculations
Topic: change in entropy
Replies: 5
Views: 28

change in entropy

Change in entropy must be smaller than zero, for the entropy to decrease? If so, why?
by AMahadi
Thu Feb 13, 2020 3:07 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: enthalpy and entropy
Replies: 3
Views: 24

enthalpy and entropy

how can the entropy change for a reaction be positive if the enthalpy change is negative?
by AMahadi
Thu Feb 13, 2020 3:04 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Delta S
Replies: 4
Views: 18

Delta S

What is delta S total, if not delta S universe? Also, do you need to factor in temperature when determining if a reaction is spontaneous?
by AMahadi
Thu Feb 13, 2020 2:55 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: equilibrium concentrations
Replies: 5
Views: 15

equilibrium concentrations

what units would we use when calculating equilibrium concentrations?
by AMahadi
Wed Feb 12, 2020 12:17 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: percent ionization
Replies: 1
Views: 15

percent ionization

How do you calculate percent ionization again?
by AMahadi
Mon Feb 03, 2020 8:07 pm
Forum: Environment, Fossil Fuels, Alternative Fuels
Topic: which section is this info in??
Replies: 5
Views: 45

Re: which section is this info in??

Do we have to know this info for the midterm?
by AMahadi
Mon Feb 03, 2020 8:07 pm
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: Midterm Review
Replies: 7
Views: 67

Re: Midterm Review

no review sheet yet! I'm sure he or Lavelle will announce it during lecture sometime this week.
by AMahadi
Mon Feb 03, 2020 8:04 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: molar entropy
Replies: 2
Views: 14

molar entropy

How could you determine which substance has a higher molar entropy at a given temperature?
by AMahadi
Mon Feb 03, 2020 8:02 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Isolated systems
Replies: 4
Views: 13

Isolated systems

what determines an isolated system from a closed system?
by AMahadi
Mon Feb 03, 2020 8:02 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: HW 4F.9
Replies: 2
Views: 20

HW 4F.9

Calculate the change in entropy when the pressure of 1.50 mol Ne(g) is decreased isothermally from 15.0 atm to 0.500 atm. Assume ideal behavior.
by AMahadi
Mon Jan 27, 2020 10:23 pm
Forum: Phase Changes & Related Calculations
Topic: internal energy
Replies: 3
Views: 27

internal energy

How do you calculate internal energy?
by AMahadi
Sat Jan 25, 2020 5:21 pm
Forum: Phase Changes & Related Calculations
Topic: revere reactions
Replies: 7
Views: 28

revere reactions

Would the opposite phases changes (vapor to liquid, and liquid to solid) always be exothermic?
by AMahadi
Sat Jan 25, 2020 5:12 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Different methods
Replies: 4
Views: 17

Different methods

How do you know which method to use to calculate ΔH?
by AMahadi
Sat Jan 25, 2020 5:08 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: bond enthalpy calculations
Replies: 2
Views: 14

bond enthalpy calculations

what is this equation, ΔH= ∑bond broke - ∑bond, used for again?
by AMahadi
Sat Jan 25, 2020 5:03 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: enthalpy reaction
Replies: 4
Views: 19

enthalpy reaction

When solving the enthalpy of a reaction using bond enthalpies, why do we perform reactants minus product while for all other enthalpy calculations we use products minus reactants?
by AMahadi
Sat Jan 25, 2020 4:52 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: standard enthalpy
Replies: 3
Views: 13

standard enthalpy

Why is the standard enthalpy of formation of an element in its most stable form zero?
by AMahadi
Sun Jan 19, 2020 5:27 pm
Forum: Ideal Gases
Topic: response to change in equilibria
Replies: 3
Views: 10

response to change in equilibria

how does a reaction respond to minimize the effect of increasing pressure?
by AMahadi
Sun Jan 19, 2020 5:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: % Ionization
Replies: 3
Views: 10

Re: % Ionization

what does it mean if x less than 5% of initial, then approximation is ok?
by AMahadi
Sun Jan 19, 2020 5:22 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: kA and kB
Replies: 1
Views: 5

kA and kB

what is the inverse relationship of kA and kB?
by AMahadi
Sun Jan 19, 2020 5:14 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ICE tables
Replies: 3
Views: 15

ICE tables

When do we use ICE tables? Is it used to find the concentrations of acid/bases and then that is used to find the poh/ph?
by AMahadi
Sun Jan 19, 2020 5:09 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: pkB and pkA
Replies: 1
Views: 9

pkB and pkA

The lower the pkA and pkB, the stronger the acid or base?
by AMahadi
Sat Jan 11, 2020 1:43 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K values
Replies: 4
Views: 37

K values

Why is K = 1 considered rare?
by AMahadi
Sat Jan 11, 2020 1:26 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Change in pressure
Replies: 5
Views: 22

Change in pressure

How does a reaction respond to minimize the effect of increasing pressure?
by AMahadi
Sat Jan 11, 2020 1:24 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Le Chatelier's Principle
Replies: 19
Views: 75

Le Chatelier's Principle

When do you use Chatelier's Principle?
by AMahadi
Thu Jan 09, 2020 2:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K and Q
Replies: 5
Views: 19

K and Q

If K and Q are equal, does that mean that the system is at an equilibrium? If so, why?
by AMahadi
Thu Jan 09, 2020 2:22 pm
Forum: Ideal Gases
Topic: K value
Replies: 14
Views: 60

K value

If the K value is large/small, what does that indicate about the product?
by AMahadi
Sun Dec 08, 2019 10:19 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Uncertainty
Replies: 5
Views: 37

Uncertainty

What does delta x signify? And do you find it?
by AMahadi
Sun Dec 08, 2019 10:17 pm
Forum: Naming
Topic: type of compound
Replies: 2
Views: 33

type of compound

What type of compound is Al2(OH)3
by AMahadi
Sat Dec 07, 2019 11:23 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent molecules
Replies: 1
Views: 23

Bent molecules

Are all bent molecules polar? If so, why?
by AMahadi
Sat Dec 07, 2019 3:44 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: oxidation number
Replies: 1
Views: 17

oxidation number

How do you find oxidation number again?
by AMahadi
Sat Dec 07, 2019 2:04 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Naming Ligands
Replies: 1
Views: 18

Naming Ligands

Is it preferred to name ligands with the IUPAC names or the other name? For example, is Cl- chloro or chlorido?
by AMahadi
Sun Dec 01, 2019 7:29 pm
Forum: Dipole Moments
Topic: dipole moments
Replies: 6
Views: 43

dipole moments

do all polar molecules have dipole moments?
by AMahadi
Sun Dec 01, 2019 7:27 pm
Forum: Naming
Topic: cis and trans
Replies: 1
Views: 14

cis and trans

Do we have to include cis and trans when writing out the names of certain molecules?
by AMahadi
Sun Dec 01, 2019 7:25 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: coordinate bonds
Replies: 1
Views: 25

coordinate bonds

In general, if you see OH (or O-), SH (or S-), or N in a molecule, can you guess that the molecule can form a coordinate bond there?
by AMahadi
Sun Dec 01, 2019 7:19 pm
Forum: Hybridization
Topic: steric number
Replies: 2
Views: 27

steric number

What is a steric number?
by AMahadi
Sun Dec 01, 2019 7:15 pm
Forum: *Crystal Field Theory
Topic: Crystal Field Theory
Replies: 3
Views: 50

Crystal Field Theory

What is the Crystal Field Theory and why is it significant?
by AMahadi
Sun Nov 24, 2019 6:26 pm
Forum: Naming
Topic: Coordination number
Replies: 7
Views: 33

Re: Coordination number

how do you calculate coordination number of complexes?
by AMahadi
Sun Nov 24, 2019 6:23 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: chelating ligands
Replies: 1
Views: 11

chelating ligands

what are chelating ligands and why are they significant?
by AMahadi
Sun Nov 24, 2019 6:19 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: diamagnetism
Replies: 5
Views: 42

Re: diamagnetism

what is the difference between diamagnetism and paramagnetism?
by AMahadi
Sun Nov 24, 2019 6:16 pm
Forum: Hybridization
Topic: stability in hybridization
Replies: 4
Views: 26

stability in hybridization

Why is sp3 more stable than sp2?
by AMahadi
Sun Nov 24, 2019 6:11 pm
Forum: Conjugate Acids & Bases
Topic: Acids and Bases
Replies: 10
Views: 58

Acids and Bases

when do you use equilibrium arrows, for an acid-base reaction or for an acid or a base reacting with water?
by AMahadi
Sun Nov 17, 2019 5:59 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 moments
Replies: 7
Views: 31

dipole moments

Are dipole moments just created when two atoms have a difference in electronegativities?
by AMahadi
Sun Nov 17, 2019 5:29 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: bond order calculations
Replies: 4
Views: 38

bond order calculations

what are the different ways to calculate bond order?
by AMahadi
Sun Nov 17, 2019 5:27 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR
Replies: 5
Views: 29

VSEPR

What is the VSEPR formula and do we have to know it?
by AMahadi
Sun Nov 17, 2019 5:21 pm
Forum: Hybridization
Topic: hybridization
Replies: 1
Views: 14

hybridization

why does hybridization occur?
by AMahadi
Sun Nov 10, 2019 5:29 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: London dispersion
Replies: 4
Views: 23

London dispersion

What type of molecules tend to have LDF? Why are LDFs considered to be the weakest of the intermolecular forces?
by AMahadi
Sun Nov 10, 2019 5:22 pm
Forum: Sigma & Pi Bonds
Topic: sigma bonds
Replies: 3
Views: 30

sigma bonds

In a bond between 2 atoms, can there only be one sigma bond?
by AMahadi
Sun Nov 10, 2019 5:19 pm
Forum: Dipole Moments
Topic: dipole moments
Replies: 2
Views: 32

dipole moments

how do you determine the length of a vector during a dipole-dipole moment?
by AMahadi
Sat Nov 09, 2019 6:32 pm
Forum: Dipole Moments
Topic: calculating dipole moments
Replies: 1
Views: 14

calculating dipole moments

how do you calculate the dipole moment of a molecule given the electronegativity values for the atoms comprising it?
by AMahadi
Tue Nov 05, 2019 8:24 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability Periodic Trend
Replies: 5
Views: 46

Re: Polarizability Periodic Trend

So cations are smaller than their parent atoms and have a lower polarizing power when compared to anions?
by AMahadi
Tue Nov 05, 2019 8:16 pm
Forum: Electronegativity
Topic: Ionic character
Replies: 2
Views: 24

Ionic character

Which bond has more ionic character, C–F or C–Br? Why?
by AMahadi
Sat Nov 02, 2019 4:25 pm
Forum: Trends in The Periodic Table
Topic: Noble Gases
Replies: 2
Views: 15

Noble Gases

Do all trends in the periodic table not apply to noble gases? If there are trends that apply, which ones?
by AMahadi
Sat Nov 02, 2019 4:07 pm
Forum: DeBroglie Equation
Topic: Determining Wave-like Properties
Replies: 4
Views: 39

Re: Determining Wave-like Properties

I'm still confused as to what the relationship between the deBroglie wavelength and the mass is? If an atom has a longer wavelength does that mean it has a lighter mass or?
by AMahadi
Sat Nov 02, 2019 3:50 pm
Forum: Electronegativity
Topic: Electronegativity and charge
Replies: 2
Views: 19

Electronegativity and charge

If there is a bigger difference in electronegativity, does that mean that the charge is higher?
by AMahadi
Sat Nov 02, 2019 3:16 pm
Forum: Electronegativity
Topic: Oxygen and Electronegativity
Replies: 5
Views: 26

Oxygen and Electronegativity

Why does oxygen have a high electronegativity and what does that indicate?
by AMahadi
Sat Nov 02, 2019 3:13 pm
Forum: Ionic & Covalent Bonds
Topic: Covalent Bonds
Replies: 1
Views: 21

Covalent Bonds

Why is water not as effective in breaking covalent bonds?
by AMahadi
Sat Oct 26, 2019 9:03 pm
Forum: Resonance Structures
Topic: Delocalized electrons
Replies: 2
Views: 14

Delocalized electrons

What are delocalized structures?
by AMahadi
Sat Oct 26, 2019 9:02 pm
Forum: Bond Lengths & Energies
Topic: Bond Lengths
Replies: 4
Views: 41

Bond Lengths

Why are double bonds shorter than single bonds? Is it more than the interactions of doubles bonds being stronger?
by AMahadi
Sat Oct 26, 2019 9:00 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Stability
Replies: 9
Views: 69

Stability

Why is the formal charge of an atom indicative of it being more stable?
by AMahadi
Sat Oct 26, 2019 8:58 pm
Forum: Lewis Structures
Topic: Resonance and lower energy levels
Replies: 2
Views: 14

Resonance and lower energy levels

Does resonance lower energy of a molecule and if so why/how?
by AMahadi
Sat Oct 26, 2019 8:53 pm
Forum: Resonance Structures
Topic: Resonance
Replies: 6
Views: 50

Resonance

Why are compounds that have more resonance often more stable?
by AMahadi
Sun Oct 20, 2019 4:53 pm
Forum: Administrative Questions and Class Announcements
Topic: Homework week 4
Replies: 4
Views: 34

Homework week 4

For week 4, is the topic for the hw the Quantum World even though we did it last week? Do we just pick 5 other problems?
by AMahadi
Sat Oct 19, 2019 4:56 pm
Forum: *Shrodinger Equation
Topic: Schrodinger Equation
Replies: 4
Views: 37

Schrodinger Equation

I understand how the Schrodinger equation works but why is it significant to know?
by AMahadi
Sat Oct 19, 2019 4:42 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: E configuration of ions
Replies: 2
Views: 20

E configuration of ions

I am confused as to how to find the e- configuration of ions.
by AMahadi
Sat Oct 19, 2019 4:39 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Electrostatic potential energy
Replies: 2
Views: 34

Electrostatic potential energy

What exactly is Electrostatic potential energy and why is significant to know when dealing with multi-electron atoms?
by AMahadi
Tue Oct 15, 2019 3:46 pm
Forum: Properties of Light
Topic: Speed of radiation
Replies: 3
Views: 24

Speed of radiation

When does the speed of radiation decrease? What has to happen in order for it to decrease?
by AMahadi
Sun Oct 13, 2019 10:56 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation
Replies: 3
Views: 28

Rydberg Equation

What does the Rydberg equation mean/help solve?
by AMahadi
Sun Oct 13, 2019 10:51 am
Forum: DeBroglie Equation
Topic: DeBroglie Equation
Replies: 9
Views: 88

DeBroglie Equation

Why can't the DeBroglie Equation be applied to light?
by AMahadi
Thu Oct 10, 2019 3:34 pm
Forum: Photoelectric Effect
Topic: threshold energy
Replies: 4
Views: 48

threshold energy

what does the threshold energy represent?
by AMahadi
Thu Oct 10, 2019 3:11 pm
Forum: Limiting Reactant Calculations
Topic: Limiting Reactant Problem
Replies: 2
Views: 60

Limiting Reactant Problem

A reaction container holds 5.77 g of P4 and 5.77 g of O2.The following reaction occurs: P4 + O2 --> P4O6. If enough oxygen is available then the P4O6 reacts further: P4O6 + O2 --> P4O10. a. What is the limiting reagent for the formation of P4O10? b. What mass of P4O10 is produced? c. What mass of ex...
by AMahadi
Thu Oct 10, 2019 3:03 pm
Forum: Balancing Chemical Reactions
Topic: Balancing Chemical Reactions
Replies: 20
Views: 212

Balancing Chemical Reactions

I'm still having some difficulty balancing equations that require more than just inspection. Is there another, possibly longer but more accurate method to balancing "harder" chemical reactions. For example: Cu + HNO3 → Cu(NO3)2 + NO + H2O
by AMahadi
Sun Oct 06, 2019 9:44 pm
Forum: Molarity, Solutions, Dilutions
Topic: Periodic table
Replies: 3
Views: 60

Periodic table

Will we be provided with a periodic table during the test?
by AMahadi
Sun Oct 06, 2019 4:32 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: avogadro's number
Replies: 4
Views: 44

avogadro's number

when do you use avogadro's number?
by AMahadi
Sun Oct 06, 2019 4:29 pm
Forum: Limiting Reactant Calculations
Topic: limiting reactant
Replies: 9
Views: 72

limiting reactant

is the limiting reactant usually the one with the smallest number of moles? why or why not?
by AMahadi
Sun Oct 06, 2019 4:23 pm
Forum: Empirical & Molecular Formulas
Topic: empirical and molecular formulas
Replies: 7
Views: 55

empirical and molecular formulas

can a compound's empirical formula be the same as its molecular formula? When can you tell?
by AMahadi
Thu Oct 03, 2019 3:49 pm
Forum: Significant Figures
Topic: Sig Figs
Replies: 6
Views: 89

Sig Figs

When are zeroes significant?
For example how many sig figs are in 32,000,000 compared to 0.3200 or 3.0200?

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