## Search found 17 matches

Mon Mar 07, 2016 9:51 am
Forum: *Haloalkanes
Topic: Priority in Numbering
Replies: 3
Views: 902

### Priority in Numbering

So is it true that all functional groups except for halogens have the priority for the lowest numbering?
Fri Mar 04, 2016 9:32 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Free Energy of Activation vs Activation Energy
Replies: 1
Views: 4357

### Re: Free Energy of Activation vs Activation Energy

Can someone please explain the difference between free energy of activation and activation energy? Thanks! Free energy of activation refers to Gibbs free energy. This is what we usually refer to when we are looking at the energy barriers of chemical reactions. Activation energy can be referred to t...
Thu Feb 25, 2016 5:31 pm
Forum: *Alkynes
Topic: Alkynes for quiz 3?
Replies: 3
Views: 1027

### Alkynes for quiz 3?

Is it necessary to worry about alkynes for this upcoming quiz? I do not see any alkynes on the course reader pages that we have been assigned for quiz 3.
Tue Feb 16, 2016 9:53 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Reaction Order
Replies: 2
Views: 506

### Re: Reaction Order

For this problem, how was the order calculated? When the NO concentration is doubled, the rate of the reaction 2 NO +O2 -> 2NO2 increases by a factor of 4. When both the O2 and the NO concentrations are doubled, the rate increases by a factor of 8. What are the reactant orders? Answer: (a) Second or...
Sat Feb 06, 2016 7:39 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.35 Typo?
Replies: 2
Views: 553

### 14.35 Typo?

For the half reaction of reduction, shouldn't it be (In3+) +(e-) ---->In2+. The solution manual states that it has a 2e-.
Sun Jan 31, 2016 3:12 pm
Forum: Balancing Redox Reactions
Topic: Oxidation vs Reduction
Replies: 2
Views: 792

### Re: Oxidation vs Reduction

I just always remember that a half reaction that shows oxidation will always have the electrons to the right side of the equation. Think of it as the separation of electrons from whatever is being oxidized. For reduction, I always think of it as the "reduction" of the charge. The reduction...
Mon Jan 25, 2016 3:30 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Q reversible
Replies: 1
Views: 1012

### Re: Q reversible

What does it mean that enthalpy is able to be reversible? What type of problem would be asked when we are to use the q reversible equation? There will be two types of problems that you will be asked. 1: Irreversible and 2: Isothermal Reversible. Irreversible will be reactions that happen immediatel...
Tue Jan 19, 2016 9:36 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard Conditions
Replies: 1
Views: 395

### Re: Standard Conditions

All gases are at 1 atm pressure. All gases are pure. The standard state temperature is 25°C (298 K). It is possible to calculate standard state values for other temperatures. So in a way, yes the pressure is constant.
Sun Jan 17, 2016 7:06 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard Enthalpy of Reaction vs. Formation
Replies: 2
Views: 1007

### Re: Standard Enthalpy of Reaction vs. Formation

Standard enthalpies of formation make up the standard enthalpy of a reaction.
Tue Jan 12, 2016 7:14 pm
Forum: Phase Changes & Related Calculations
Topic: work done in irreversible vs reversible process (HW 8.27)
Replies: 2
Views: 508

### Re: work done in irreversible vs reversible process (HW 8.27

Chem_Mod wrote:You are heading to the right direction. Hint for your question, recall the formula of ideal gas PV=nRT

I solved it thanks!
Tue Jan 12, 2016 11:04 am
Forum: Phase Changes & Related Calculations
Topic: work done in irreversible vs reversible process (HW 8.27)
Replies: 2
Views: 508

### work done in irreversible vs reversible process (HW 8.27)

Calculate the work for each of the following processes beginning with a gas sample in a piston assembly with T  305 K, P  1.79 atm, and V  4.29 L: (a) irreversible expansion against a constant external pressure of 1.00 atm to a final volume of 6.52 L; (b) isothermal, reversible expansion to a fin...
Tue Jan 12, 2016 10:59 am
Forum: Phase Changes & Related Calculations
Topic: Homework Problem 8.21
Replies: 6
Views: 3260

### Re: Homework Problem 8.21

should be something like this: heat released = heat absorbed 20 (mass)*0.39 (specific heat of Cu) *(100-T) (change in temperature) = 50.7 (mass)* 1 (specific heat of H2O) *(T-22)(change in temperature) Try to solve for T. I got 32.4 degree Celsius as the final temperature. Thanks you gave me the ri...
Tue Jan 12, 2016 10:43 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Different Calorimeters
Replies: 1
Views: 260

### Re: Different Calorimeters

Does anyone know where I can find a picture of a calorimeter used for constant P calorimetry? Also I'm still confused why the pressure is constant and for the other the volume is constant.[/quote] https://www.google.com/search?q=constant+pressure+calorimeter&rlz=1C1ASRM_enUS556US556&espv=2&a...
Mon Jan 11, 2016 10:57 pm
Forum: Phase Changes & Related Calculations
Topic: Homework Problem 8.21
Replies: 6
Views: 3260

### Homework Problem 8.21

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. I am assuming that this has something to do with the equation q=n...
Sun Jan 10, 2016 5:21 pm
Forum: Phase Changes & Related Calculations
Topic: Formula for sublimation enthalpy
Replies: 3
Views: 10548

### Re: Formula for sublimation enthalpy

Don't solids that sublimate directly form vapors and not liquids? How is the enthalpy of fusion found to calculate enthalpy of sublimation? Sublimation is the conversion from a solid to a gas. In the case of water, yes solid directly to a vapor. When Lavelle discussed this in lecture, he explained t...
Sat Jan 09, 2016 10:09 pm
Forum: Phase Changes & Related Calculations
Topic: Using table 8.2
Replies: 1
Views: 441

### Re: Using table 8.2

I am assuming that you are doing problem 39. I think this problem requires you to use the formula q=n(Cs)(Delta T). N stands for the grams,the Cs stands for specific heat capacity, and the Delta T is the change in temperature. Which means you are using the column to the left of table 8.2 for the Cs....
Sat Jan 09, 2016 8:12 pm
Forum: Phase Changes & Related Calculations
Topic: Chapter 8 Homework Question 8.37
Replies: 2
Views: 1029

### Chapter 8 Homework Question 8.37

At its boiling point, the vaporization of 0.579 molCH4(l) requires 4.76 kJ of heat. What is the enthalpy of vaporization of methane? -Is it acceptable to use ratios to solve this problem? For example: .579 molCH4/4.76 kJ= 1 molCH4/x. I get the correct answer, but I just want to know if this is the c...

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