CHEMISTRY COMMUNITY

lizettelopez1F

Why can we not add the cell potential of elementary steps?

lizettelopez1F

It can also be used in the equation of delta U=q+w. You can substitute w with -PdeltaV if w is not given to you in the problem.

lizettelopez1F

When would we use the values Cp= (5/2)R and Cv=(3/2)R?

lizettelopez1F

Did anyone understand what delta G should be for the question from test 2 where it talks about photosynthesis of an old tree?

lizettelopez1F

To figure out the order, you would keep in mind that the graph you need to take into consideration is concentration over time.

lizettelopez1F

What's the formula for instantaneous rate and average rate?

lizettelopez1F

delta G=0 when the reaction has reached equilibrium

lizettelopez1F

Since electrons are constantly being gained or lost, the solutions of the cathode and anode may gain a charge. If the solutions have a charge, the transferring of electrons will come to a stop. To allow the electrons to continue to be transferred, the salt bridge needs to maintain the solutions neut...

lizettelopez1F

What is the difference between instantaneous rate, average rate, and unique rate?

lizettelopez1F

If a reaction is spontaneous, it can either be spontaneous with all temperatures, spontaneous with low temperatures, or spontaneous with high temperatures. You can tell by looking at the values of delta H and delta S.

lizettelopez1F

Cp=5/2r is used when you need to find the heat capacity of an ideal gas with a constant pressure. Cv=3/2R is used when you need to find the heat capacity of an ideal gas with a constant volume

lizettelopez1F

Gibbs is the free energy of a system that is available to do work. Delta G is the change of free energy that is equal to the delta H (change of enthalpy) minus the product of temperature and delta S (the change of entropy).

lizettelopez1F

Is ΔH always equal to qp? Also, under what circumstances does ΔH=ΔU?

lizettelopez1F

X represents the number of states and I believe that the number of states will always be given to us

lizettelopez1F

What is the difference between the equation mentioned above and the equation S=k(b) ln w?

lizettelopez1F

To add to the previous comment, when a question says work is being done by the surroundings "w" is positive. If a question says work is being done on the surroundings "w" is negative.

lizettelopez1F

A negative entropy means that the disorder of a system has decreased. For example, when a liquid freezes into a solid there is a negative entropy. A positive entropy means that there is an increase in disorder. Entropy increases from solid to liquid to gas. For example, when a liquid vaporizes entro...

lizettelopez1F

A piece of copper of mass 20.0 g at 100.0 C is placed in a vessel of negligible heat capacity but containing 50.7 g of water at 22.0 C. Calculate the final temperature of the water. Assume that no energy is lost to the surroundings. What is the general equation that needs to be used to find the fina...

lizettelopez1F

Cp is always greater because of the work of expansion it has to do.

lizettelopez1F

We need to take into account the heat needed to raise the temperature of the copper kettle because heating the copper kettle will allow the temperature of the water to increase.

lizettelopez1F

How do you identify a weak acid and a weak base?

lizettelopez1F

In the homework, there are problems that require you to find Ka or Kb. The textbook says that you must refer to the acid and base tables that give you either Ka or Kb. However, I noticed that not all acids and bases are on the table, so how would I find Ka or Kb for an acid or base that is not menti...

lizettelopez1F

Keep in mind that you can solve for x using approximation if the Ka is less than 10^-3

lizettelopez1F

Emily Kennedy 4L wrote:if the approximation is above 5% then is the complete answer void?

If it is greater than 5%, the quadratic equation should be used instead to find x.

lizettelopez1F

Endothermic reactions requires heat while forming products then heating will favor product formation. If the temperature increases in an endothermic reaction, it will shift to the right. If the temperature decreases in an endothermic reaction, it will shift to the left. Exothermic reactions give off...

lizettelopez1F

If we are not given Ka, can we just find Ka by using an ice table?

lizettelopez1F

204929947 wrote:what does PV=nRT stand for???

It represents the ideal gas law.
P= Pressure, V=volume, n= number of moles, R= constant, T= Temperature

lizettelopez1F

Pressure= atm
V=liters
T=Kelvin
R= .0821 (liters x atm)/(moles x kelvin)
Pressure is usually given in atm, so the units of R would be the unit mentioned above. However, if pressure is given in another unit, the unit of R also changes to correspond to the unit of pressure that is given.

lizettelopez1F

A catalyst speeds up the the forward and back reaction by the same amount, which does not change the position of equilibrium.

CHEMISTRY COMMUNITY

Search found 29 matches

Elementary Steps

Re: w=-PdeltaW

Cp vs Cv

Re: Test 2

Re: Meaning of Zero, First, and Second Order?

Re: Instantaneous vs Average

Re: delta G = 0 ??

Re: salt bridge

Kinetics

Re: gibbs free energy

Re: 5/2R vs 3/2R

Re: Gibbs concept

ΔH

Re: Degeneracy

Re: thermo equation explanation

Re: +/- work values

Re: negative and positive entropy

6th Edition Problem 8.21

Re: Cv versus Cp

Re: 6th edition hw problem 8.19

Re: Setting up Equilibrium Equations

Finding Ka or Kb

Re: Calculating the pH - 6D.17 7th edition

Re: 5% rule

Re: Temperature

Re: Ka and Kb as Inverses?

Re: When to Use PV=nRT

Re: R [ENDORSED]

Re: Catalyst