Search found 17 matches

by Huanyu Nie 2A
Tue Mar 08, 2016 9:53 am
Forum: *Haloalkenes
Topic: Priority for different bonds and functional groups
Replies: 1
Views: 798

Priority for different bonds and functional groups

If a compound has both triple bond and double bond, which one should have priority for numbering? On page 50 of the orange textbook, the upper right molecule contains a double and a triple bond and the double has a lower number. I'm confused if the rule is affected by the halogenated groups.
by Huanyu Nie 2A
Sun Mar 06, 2016 7:55 pm
Forum: *Calculations Using ΔG° = -RT ln K
Topic: -2.3030 RT logKeq
Replies: 1
Views: 795

Re: -2.3030 RT logKeq

You can see that it converts log to ln, so there will be a difference in the number. I think you can use either equation.
by Huanyu Nie 2A
Sun Feb 28, 2016 12:49 pm
Forum: *Electrophiles
Topic: "+" sign of electrophile
Replies: 1
Views: 332

"+" sign of electrophile

What does the "+" sign mean in an electrophile? Does it indicate the positive charge of the atom or it just indicates that it is an electron deficient region? Is it the same for the nucleophile?
by Huanyu Nie 2A
Mon Feb 15, 2016 8:46 pm
Forum: First Order Reactions
Topic: finding t 15.37
Replies: 2
Views: 481

Re: finding t 15.37

Well I think you are doing right. The textbook just moves the constant to the other side of the equation.
by Huanyu Nie 2A
Mon Feb 15, 2016 8:42 pm
Forum: Second Order Reactions
Topic: Quiz Prep 2 Winter 2015 #10
Replies: 1
Views: 348

Re: Quiz Prep 2 Winter 2015 #10

The statement is only true for first-order reaction. Because half-life for 1st order reactions is ln2/k which has nothing to do with the initial concentration. For 2nd order reaction it is 1/k[A]0, which means the half life depends on the initial concentration. This reaction is a 2nd order and the i...
by Huanyu Nie 2A
Mon Feb 15, 2016 8:34 pm
Forum: First Order Reactions
Topic: Half-life
Replies: 2
Views: 463

Re: Half-life

Sorry I don't understand what 1[A]/2[A] is but the number 0.693 is the value of ln2. half life for first-order reaction can be calculated from the fomula: t=ln2/k. Hope it helps!
by Huanyu Nie 2A
Mon Feb 15, 2016 8:29 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Overall rate law and the slowest step
Replies: 1
Views: 296

Overall rate law and the slowest step

The textbook says that the slowest step governs the overall rate law and the steps following the slowest step take place so fast that they barely contribute to the overall rate law. Does it mean when we are trying to find the overall rate law, all steps after the slow step can be ignored?
by Huanyu Nie 2A
Tue Feb 09, 2016 9:58 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: W for BH2F
Replies: 3
Views: 1744

Re: W for BH2F

kB is given. It is defined as R=kB*NA (2.03*10^23).
by Huanyu Nie 2A
Sat Feb 06, 2016 11:10 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Deciding which species will be produced at an electrode
Replies: 1
Views: 325

Deciding which species will be produced at an electrode

In self-test 14.13A the electrolysis of AgNO3, why is Ag produced at the cathode? The reduction potential of Ag is 0.80V which is smaller than that of O2 (1.32V). Doesn't it mean that Ag is more easily oxidized than water and shouldn't it be Ag+ at anode? I just get completely confused about this ki...
by Huanyu Nie 2A
Sat Feb 06, 2016 2:07 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Self test 14.5B-the reactants|products order
Replies: 1
Views: 270

Self test 14.5B-the reactants|products order

The left side reaction is 2Hg+2HCl--->Hg2Cl2+2e-. If Hg2Cl2 is the product, why in the cell diagram it is between Hg and HCl? (Hg(l)|Hg2Cl2(s)|HCl(aq))
by Huanyu Nie 2A
Sat Feb 06, 2016 1:32 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Example14.4
Replies: 1
Views: 328

Example14.4

The question asks me to write the reaction for the cell Pt(s)|H2(g)|HCl(aq)|Hg2Cl2(s)|Hg(l). If there is no salt bridge, how am I going to know which part is involved in reduction or oxidation?
by Huanyu Nie 2A
Thu Feb 04, 2016 11:43 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: HW Problem 14.13b
Replies: 1
Views: 236

Re: HW Problem 14.13b

Because I2 is not a metal. Just remember that even there is solid in it you still need the Pt electrode for the reaction to take place.
by Huanyu Nie 2A
Thu Feb 04, 2016 11:35 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Example14.3
Replies: 1
Views: 270

Example14.3

example 14.3 on page 572 is asking to calculate the reaction Gibbs free energy given that the solution of copper and zince ions is 1.00 mol/L, why is the n 2 mol? Does it have anything to do with the concentration 1.00 mol/L or it is because there are two moles of electrons transfered from zinc to c...
by Huanyu Nie 2A
Mon Feb 01, 2016 12:02 am
Forum: Phase Changes & Related Calculations
Topic: Quick significant figures question
Replies: 4
Views: 722

Re: Quick significant figures question

What if we are using the constant numbers such as R the gas constant? It has a lot of figures in it so I am confused how many significant numbers I should keep in the answer. And how about atomic weight? How many significant numbers shall we take?
by Huanyu Nie 2A
Sun Jan 24, 2016 10:41 pm
Forum: Calculating Work of Expansion
Topic: What is Free Expansion? (9.47)
Replies: 3
Views: 574

Re: What is Free Expansion? (9.47)

Free expansion is like gas expanding into vacuum. Because there is no external pressure, there is no work done. Irreversible process is one that cannot be reversed by a small change in the external pressure (always a big difference between the external and internal pressure). Both of them cannot be ...
by Huanyu Nie 2A
Sun Jan 24, 2016 10:33 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Questions about the unit of the standard enthalpy.
Replies: 1
Views: 333

Questions about the unit of the standard enthalpy.

In Example 8. 10 on p.296, the unit of the answer (the standard enthalpy of reaction) is kJ. There is a note below emphasizing that enthalpies of reaction are expressed in kJ. However the next question (Self-Test 8.14 A) asked about the same thing but the unit is "kJ per mol". Lots of ques...
by Huanyu Nie 2A
Tue Jan 12, 2016 10:07 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Different Calorimeters
Replies: 1
Views: 248

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.

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