Search found 12 matches

by Cherry_Deng_1K
Sun Mar 19, 2017 10:51 am
Forum: *Alkanes
Topic: Numbering
Replies: 1
Views: 257

Re: Numbering

Hello, It does matter where you start numbering the carbons. In this case, you would want to assign lower numbers alphabetically. Since E comes before M, you would assign the lower number to ethyl and the higher number to methyl. Therefore, the name of the hydrocarbon would be 1-ethyl-3-methyl cyclo...
by Cherry_Deng_1K
Wed Mar 15, 2017 7:59 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: #8.101.c
Replies: 2
Views: 406

Re: #8.101.c

Hello, I think you misread. The solution manual says 0.030 mol SO3 and 0.015 mol O2 will remain in the container, which makes sense. You are correct that SO2 is the limiting reactant, so all 0.030 mol of SO2 will be used up and converted to 0.030 mol SO3, with 0.015 mol O2 remaining. Therefore, ther...
by Cherry_Deng_1K
Fri Mar 10, 2017 9:53 am
Forum: *Complex Reaction Coordinate Diagrams
Topic: 4.29
Replies: 2
Views: 476

Re: 4.29

Also, most electrophilic addition reactions involving double bonds are exothermic since the pi bond that is broken is weaker than the single bonds that are formed.
by Cherry_Deng_1K
Sun Mar 05, 2017 12:33 am
Forum: *Alkanes
Topic: 2-Iodobutane [ENDORSED]
Replies: 1
Views: 182

Re: 2-Iodobutane [ENDORSED]

Hello, If you recall the rules for numbering the carbons, you assign the smallest number possible to the substituent. If you look at CH3CH2CHICH3 from left to right, it would be 3-iodobutane, but 3 is bigger than 2. In the case of 2-iodobutane, you can number the carbons from right to left in order ...
by Cherry_Deng_1K
Fri Feb 24, 2017 10:07 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: Homework 15.19 c & d
Replies: 3
Views: 320

Re: Homework 15.19 c & d

Hello,

I also had the same problem until I realized what I forgot to do. The units of the rate constant should be (L^4)/[(mol^4)(s)]. You have to convert the initial concentrations in the experimental set of concentrations you use from mmol/L to mol/L. That will get you 2.85 x 10^12.
by Cherry_Deng_1K
Thu Feb 23, 2017 11:55 pm
Forum: General Rate Laws
Topic: When B and C is significantly larger than A
Replies: 3
Views: 328

Re: When B and C is significantly larger than A

Also, I am pretty sure a question will tell you that the concentrations of B and C are significantly larger than A. You will probably not know to write a pseudo-first-order rate law (or other order depending on the reaction) otherwise.
by Cherry_Deng_1K
Wed Feb 15, 2017 11:30 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Ideal Gas Law- delta U
Replies: 1
Views: 260

Re: Ideal Gas Law- delta U

Hey there! First of all, w=0 when there is no volume change because it means that the system is not doing any work (imagine a system where work causes a piston to move up and down. If the volume of the system doesn't change, then the piston isn't moving, so no work is being done). For your question ...
by Cherry_Deng_1K
Wed Feb 08, 2017 7:58 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Calculating Equilibrium constant
Replies: 1
Views: 168

Re: Calculating Equilibrium constant

Hello, For part (a), I would start by using the equation ΔG°= -RT ln K. Since the standard reaction free energy is already given, you can just directly substitute ΔG°, R, and T to find the equilibrium constant, K. Since ΔG° is given in kJ and the unit for R is J/(K mol), don't forget to convert kJ t...
by Cherry_Deng_1K
Mon Jan 30, 2017 1:49 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.99 HW problem
Replies: 3
Views: 354

Re: 8.99 HW problem

Sorry if my explanation was unclear. All of the enthalpies of formation that you'll need to calculate the enthalpy of reaction is given in Appendix 2A. To find the ΔHf for ZnCl2 (aq), you first find the ΔHf for Zn 2+ (aq), which is the -153.89 kj/mol. You add that with 2 times the ΔHf of Cl - (aq) s...
by Cherry_Deng_1K
Mon Jan 23, 2017 9:43 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.99 HW problem
Replies: 3
Views: 354

Re: 8.99 HW problem

Hello, In this case, you will have to look up the enthalpies of formation for each component of the reaction and add them up to find the enthalpy of reaction. If you look at Appendix 2A (page A10), the enthalpies of formation are listed there. Since H2(g) is the most stable form of hydrogen and Zn(s...
by Cherry_Deng_1K
Tue Jan 17, 2017 7:38 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Ch 8 Q 53
Replies: 4
Views: 403

Re: Ch 8 Q 53

That's the first step! By finding q(reaction), we can find ΔU. If you look on page 10 of the course reader, it's mentioned that ΔU=qv, meaning the volume is constant. Since we know that a reaction taking place in a bomb calorimeter will not experience a change in volume, we can use ΔU=q (at constant...
by Cherry_Deng_1K
Sun Jan 15, 2017 4:57 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Ch 8 Q 53
Replies: 4
Views: 403

Re: Ch 8 Q 53

Hello, The reaction is considered the system, while the calorimeter, where the reaction is taking place, is the surroundings. The heat of the system and the heat of the surroundings should add up to 0, meaning q(system) + q(surroundings)=0, or, in the case of #53, q(reaction) + q(calorimeter)=0. Any...

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