CHEMISTRY COMMUNITY

mhuang 1E

Could someone explain how to draw structures for the activated complex and what is the activated complex?

mhuang 1E

Do you mean when:
A+B--> C+C
rate law = Rate= k[A][B]
or
A+A+B-->C+C
rate law = Rate = k[A]^2[B]

The product isn't part of the rate.

mhuang 1E

I think there was a typo in the solutions manual in that the setup is:
lnk(k'/k)=E/R((1/T)-(1/T'))
ln(k'/k)=(38kJ/mol)/(.008314kJ/K*mol)((1/298K)-(1/310K)) = .59
(k'/k)= 1.8
k=1.5x10^10 L/mol*s
Solve for k'
k'=2.7 x 10^10 L/mol*s

mhuang 1E

Each different order type has different units because as Harrison replied on my previous post: "Zero - rate of reaction is equal to rate constant k 1st order - depends on only ONE reactant concentration 2nd order - depends on two different reactants or one reactant squared" So, that would ...

mhuang 1E

For this question, I tried solving for the order of [C] and got stuck. The solutions manual says that "C is independent of the rate." What does this mean? This means that C is a zero order reaction: it doesn't depend (or is affected) by the rate. When you compare experiments 1 and 4, you ...

mhuang 1E

Could someone clarify what exactly is zero, first and second order reactions?

mhuang 1E

Thank you! For 19(a) and 19(c), I was confused on when to only add Pt(s) on one side of the cell diagram and when to add Pt(s) on both sides of the cell diagram.

mhuang 1E

When do we include inert solids such as Pt(s) in our cell diagrams and in 15(c), why does the cell diagram include KOH on the anode side and Ni(s) on the cathode side?

mhuang 1E

Are the posts counted weekly or is it cumulative throughout the quarter and then counted towards the end?

mhuang 1E

For clarification, I was wondering why the moles of solid products are mored than moles of solid reactants?

mhuang 1E

To add on, if the standard reaction enthalpy for a certain rxn is negative, that means that the rxn is exothermic (indicating that heat is released, or that energy leaves the system.) To contrast, if the standard reaction enthalpy for the rxn is positive, that means that the rxn is endothermic (indi...

mhuang 1E

From what I read on another post, it's said that if the temperature is not explicitly statedg, we can assume that the reaction is occurring at standard temperature, which is 25C (room temp) or 298K.

mhuang 1E

I was also confused on how the enthalpy of the rxn would be 0 from the solutions manual. How does 1 C-C bond, 4 C-H bonds, and 1 H-H bond equal to 1 C-C bond, and 6 C-H bonds from the products?

mhuang 1E

Because we're dealing with gases, use the ideal gas law: PV=nRT.
work=-p(delta v)=-(delta n)RT= -(1mol OF2)(8.314 JK^-1mol-^-1)(298K)=-2.48KJ
(Use 298K because we assume the rxn occurs at room temp.)
Because we are finding the change of internal energy:
(delta U)= q+ w= -318 KJ-2.48 KJ= -320KJ

mhuang 1E

Also, though final equations can have fractions has coefficients, we typically use whole numbers instead, just so that it's easier to calculate and work with.

mhuang 1E

I'd tell a chemistry joke, but I know I wouldn't get a rxn.

mhuang 1E

To add on, could someone expand what is the ideal gas constant?

mhuang 1E

I had a question regarding finding the number of moles for the mols of NH3 formed in the rxn: NH4(NH2CO2)(S) ⇋ 2NH3(g) + O2(g). The solutions manual uses the moles fo CO2 to find the number of mols for NH3 (2 mol of NH3 formed per mol of CO2; number of mol for NH3= 2x3.95x10^-4 = 7.90 x10^-4). But, ...

mhuang 1E

I was wondering if anyone could elaborate on how to find how many (and what) values of m1 are allowed for an electron for a specific sub-shell. For example, on #2.19b, it asks for the values of m1 for a 6d subshell. A d-orbital would have 5 orbitals and thus have 5 values for m1(-3,-2,-1,0,1,2,3). S...

mhuang 1E

I also have a question on #33, but not related to what is above. I am wondering how, in part a, you get the mass? The answer in the book says that the mass is 9.1*10^-31, but that is not given in the question and I am unsure how you would figure that out. The mass of the electron is given in the ba...

mhuang 1E

For the problems given in the book, the textbook uses the constant c= 2.998 x 10^8 m/s, while the module examples use 3.00 x 10^8 m/s. For the problems assigned, should we use what is given in the textbook, or what is used in the module?

mhuang 1E

Hi! I'm having some problem deciding/knowing how many significant figures to use for each problem. For example, in F5, the solutions manual shows that the mass percentage composition for C is 52.15%, while the mass percentage composition for H is 9.3787%. Could anyone explain why the answer for H ca...

CHEMISTRY COMMUNITY

Search found 22 matches

15.85 Drawing structures for activated complex

Re: rate law

Re: 15.63

Re: Orders and units

Re: Homework question 15.17

Order of reactions?

Re: Cell Diagram

Cell Diagram

Re: Chem Community Posts

9.37d

Re: 8.101e

Re: 8.49 [ENDORSED]

Re: 8.73 part C

Re: 8.49

Re: Hess's Law Details

Re: Post All Chemistry Jokes Here

Re: HW Question 8.9

11.41

Values of m1 orbitals [ENDORSED]

Re: CHAPTER 1 QUESTION 33!!!

Speed of Light Constant

F5: Problem deciding significant figures