CHEMISTRY COMMUNITY

Ishita Monga 1B

Do we need to be able to use steady state approximation to write rate laws for a proposed reaction mechanism?

Ishita Monga 1B

Do more resonance structures contribute to a higher residual entropy?

Ishita Monga 1B

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.

Ishita Monga 1B

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...

Ishita Monga 1B

When do you convert the units to standard (mols/Ls)? sometimes the book leaves the answer in different units and sometimes it converts it

Ishita Monga 1B

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?

Ishita Monga 1B

the units themselves have no impact on the numerical answer, unless they involve a conversion factor (for example mmol to mol)

Ishita Monga 1B

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.

Ishita Monga 1B

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 ...

Ishita Monga 1B

are you referring to standard potential of a cell?

Ishita Monga 1B

Do you use commas or a single line when separating aqueous and gas?

Ishita Monga 1B

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

Ishita Monga 1B

What is the difference between deltaS^o and deltaS_tot?

Ishita Monga 1B

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 -.

Ishita Monga 1B

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.

Ishita Monga 1B

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?

Ishita Monga 1B

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.

Ishita Monga 1B

what is the unit of E°?

Ishita Monga 1B

If electrons are leaving the anode and going towards the cathode, how is the anode negatively charged?

Ishita Monga 1B

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...

Ishita Monga 1B

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.

Ishita Monga 1B

What is the unit for entropy?

Ishita Monga 1B

Does work always occur when there is a change in volume?

Ishita Monga 1B

Is a vacuum an isolated system?

Ishita Monga 1B

What is the difference between standard enthalpy of formation and standard reaction enthalpy?

Ishita Monga 1B

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.

Ishita Monga 1B

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.

Ishita Monga 1B

Why are the units for temperature in heat capacity sometimes written in terms of kelvin and other times in celsius?

Ishita Monga 1B

is there a difference between enthalpy and heat?

Ishita Monga 1B

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

follow up- what is deposition?

Ishita Monga 1B

What is the difference between heat and thermal energy?

CHEMISTRY COMMUNITY

Search found 31 matches

Steady state approximation

Resonance and Entropy

Re: The universe

Re: Rate of formation/consumption

units

Re: Unique Rate. [ENDORSED]

Re: Units of k [ENDORSED]

Re: 15.15 Rate Law

Re: Reversing Half-Reactions

Re: Reduced State to Standard State

Cell diagram [ENDORSED]

Re: Reaction order

entropy

Re: entropy sign

Re: Molar entropies

entropy and moles

Re: Number of Bonds and Entropy

unit of standard reduction potential

Anode and cathode charges

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

Re: Heat Capacity

unit of entropy

Work and Volume

system of vacuum

standard enthalpy of formation

Re: 8.5

Re: Work vs. Heat

K vs C

enthalpy vs heat

Re: Phase Changes

Heat vs thermal energy