Search found 31 matches

by Ishita Monga 1B
Mon Mar 12, 2018 5:39 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Steady state approximation
Replies: 1
Views: 80

Steady state approximation

Do we need to be able to use steady state approximation to write rate laws for a proposed reaction mechanism?
by Ishita Monga 1B
Mon Mar 12, 2018 4:34 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: Resonance and Entropy
Replies: 2
Views: 350

Resonance and Entropy

Do more resonance structures contribute to a higher residual entropy?
by Ishita Monga 1B
Mon Mar 12, 2018 4:27 pm
Forum: Phase Changes & Related Calculations
Topic: The universe
Replies: 9
Views: 345

Re: The universe

Would a 20mL vial filled with an organic solvent be open or isolated? and why? A vial would be an open system because it can exchange both heat and matter with its surroundings. If the vial was closed, it would be a closed system. If the vial was closed and insulated, it would be an isolated system.
by Ishita Monga 1B
Tue Mar 06, 2018 2:34 pm
Forum: General Rate Laws
Topic: Rate of formation/consumption
Replies: 3
Views: 121

Re: Rate of formation/consumption

It depends on whether you're looking at the rate of consumption/formation of a specific species or the unique rate of reaction. If you're trying to find the unique rate of reaction it doesn't matter what species you use as long as you divide by the coefficient and use the proper sign depending on if...
by Ishita Monga 1B
Mon Mar 05, 2018 11:55 pm
Forum: Experimental Details
Topic: units
Replies: 4
Views: 421

units

When do you convert the units to standard (mols/Ls)? sometimes the book leaves the answer in different units and sometimes it converts it
by Ishita Monga 1B
Mon Mar 05, 2018 9:34 pm
Forum: *Complex Reaction Coordinate Diagrams
Topic: Unique Rate. [ENDORSED]
Replies: 4
Views: 952

Re: Unique Rate. [ENDORSED]

does that mean that the unique rate is multiplied by the coefficient in order to find the rate of consumption/formation for a specific reactant/product?
by Ishita Monga 1B
Thu Mar 01, 2018 3:41 pm
Forum: Zero Order Reactions
Topic: Units of k [ENDORSED]
Replies: 13
Views: 389

Re: Units of k [ENDORSED]

the units themselves have no impact on the numerical answer, unless they involve a conversion factor (for example mmol to mol)
by Ishita Monga 1B
Thu Mar 01, 2018 3:37 pm
Forum: General Rate Laws
Topic: 15.15 Rate Law
Replies: 4
Views: 342

Re: 15.15 Rate Law

ClaireHW wrote:For this problem, why aren't the products considered in the rate law?

(Claire Woolson Dis 1K)


to make calculations easier we only consider the reactants when determining the rate law.
by Ishita Monga 1B
Mon Feb 26, 2018 4:11 pm
Forum: Balancing Redox Reactions
Topic: Reversing Half-Reactions
Replies: 2
Views: 141

Re: Reversing Half-Reactions

If you are going from reduction potentials to oxidation potentials, the sign should be reversed. If you're referring to solving for cell potential, whether or not you reverse the E value depends on what method you are using to calculate the cell potential. If you do cathode-anode, you don't reverse ...
by Ishita Monga 1B
Fri Feb 23, 2018 12:07 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Reduced State to Standard State
Replies: 1
Views: 99

Re: Reduced State to Standard State

are you referring to standard potential of a cell?
by Ishita Monga 1B
Fri Feb 23, 2018 12:06 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell diagram [ENDORSED]
Replies: 4
Views: 169

Cell diagram [ENDORSED]

Do you use commas or a single line when separating aqueous and gas?
by Ishita Monga 1B
Fri Feb 23, 2018 12:03 pm
Forum: First Order Reactions
Topic: Reaction order
Replies: 4
Views: 189

Re: Reaction order

Pick two experiments that have an equal concentration of one reactant. Compare the ratio of the rate of reaction of the two experiments to solve for n or m.
The overall reaction order is the sum of n+m
by Ishita Monga 1B
Mon Feb 12, 2018 3:30 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: entropy
Replies: 4
Views: 225

entropy

What is the difference between deltaSo and deltaStot?
by Ishita Monga 1B
Mon Feb 12, 2018 3:25 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: entropy sign
Replies: 5
Views: 202

Re: entropy sign

If the mols of gas are increasing as a result of the reaction, entropy is +. If the mols of gas are decreasing, entropy is -.
If the reactants are changing from solid to liquid or liquid to gas, entropy is +. If they are changing from gas to liquid or liquid to solid, entropy is -.
by Ishita Monga 1B
Mon Feb 12, 2018 3:23 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Molar entropies
Replies: 5
Views: 383

Re: Molar entropies

905022356 wrote:Okay, I get that conceptually, but how do we calculate them? Do we measure them experimentally or?


If we have to use molar entropies in a calculation they will be given to us.
by Ishita Monga 1B
Sun Feb 11, 2018 4:44 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: entropy and moles
Replies: 2
Views: 255

entropy and moles

Does the entropy of reaction change due to the number of mols changing (regardless of phase) or only if the mols of gas change?
for example, if the reactants were two mols of solid and the product is one mol of solid, would entropy still decrease or is it only relative to the mols of gas?
by Ishita Monga 1B
Sun Feb 11, 2018 12:59 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Number of Bonds and Entropy
Replies: 3
Views: 126

Re: Number of Bonds and Entropy

A molecule's entropy increases as its complexity increases, so yes the number of bonds can be used to compare the entropy of two molecules.
by Ishita Monga 1B
Mon Feb 05, 2018 4:10 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Anode and cathode charges
Replies: 2
Views: 123

Anode and cathode charges

If electrons are leaving the anode and going towards the cathode, how is the anode negatively charged?
by Ishita Monga 1B
Sat Feb 03, 2018 1:31 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: What does it mean for a reaction to be "thermodynamically favored?"
Replies: 6
Views: 4187

Re: What does it mean for a reaction to be "thermodynamically favored?"

Whether or not a reaction is favored is determined by deltaG. You have to use the relation deltaG=deltaH - TdeltaS in order to determine favorability. If a reaction has a negative enthalpy and entropy increases over the course of the reaction, then a negative minus a positive is still negative. Thus...
by Ishita Monga 1B
Tue Jan 30, 2018 12:13 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat Capacity
Replies: 8
Views: 455

Re: Heat Capacity

The slope would be steeper for a lower heat capacity because the the same amount of energy input (x axis) would cause a greater increase in temperature (y axis), compared to something with a high heat capacity.
by Ishita Monga 1B
Mon Jan 29, 2018 11:20 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: unit of entropy
Replies: 11
Views: 354

unit of entropy

What is the unit for entropy?
by Ishita Monga 1B
Tue Jan 23, 2018 10:31 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Work and Volume
Replies: 2
Views: 94

Work and Volume

Does work always occur when there is a change in volume?
by Ishita Monga 1B
Tue Jan 23, 2018 10:29 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: system of vacuum
Replies: 4
Views: 183

system of vacuum

Is a vacuum an isolated system?
by Ishita Monga 1B
Mon Jan 22, 2018 9:26 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: standard enthalpy of formation
Replies: 3
Views: 132

standard enthalpy of formation

What is the difference between standard enthalpy of formation and standard reaction enthalpy?
by Ishita Monga 1B
Sat Jan 20, 2018 8:08 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: 8.5
Replies: 3
Views: 171

Re: 8.5

The "work" isn't being compressed, the system as a whole (in this case the gas in the piston) is compressed due to a certain amount of work being done to it. When work is done to the system, the value of the work is positive.
by Ishita Monga 1B
Sat Jan 20, 2018 8:03 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Work vs. Heat
Replies: 6
Views: 281

Re: Work vs. Heat

804899546 wrote:Does the energy that gets transferred into heat always have to be equal to or greater than the energy converted into work, or can either be larger than the other?


Heat and work are not dependent on each other.
by Ishita Monga 1B
Mon Jan 15, 2018 10:36 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: K vs C
Replies: 6
Views: 209

K vs C

Why are the units for temperature in heat capacity sometimes written in terms of kelvin and other times in celsius?
by Ishita Monga 1B
Sat Jan 13, 2018 7:58 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: enthalpy vs heat
Replies: 2
Views: 146

enthalpy vs heat

is there a difference between enthalpy and heat?
by Ishita Monga 1B
Sat Jan 13, 2018 7:49 pm
Forum: Phase Changes & Related Calculations
Topic: Phase Changes
Replies: 13
Views: 543

Re: Phase Changes

Sue Xu 2K wrote:Condensation, solidification and deposition are all exothermic phase change that release heat during the process.

follow up- what is deposition?
by Ishita Monga 1B
Sat Jan 13, 2018 4:18 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat vs thermal energy
Replies: 2
Views: 100

Heat vs thermal energy

What is the difference between heat and thermal energy?

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