Recent content by oferon

  1. O

    Entropy of isothermal process reversible\irreversible

    We were shown in class how to get those entropys. For reversible isothermal - ΔT=0 thus ΔE=0 thus Q = -W. ΔS(sys) = Qrev/T = nR(V1/V2) And ΔS(surr) = -nR(V1/V2) because surroundings made opposite work. For irreversible isothermal in vacuum - ΔT=0 thus ΔE=0. No work is done by...
  2. O

    A simple question in thermodynamics

    But on both processes I start with same Pi and Vi, and end up with same Pf and Vf. I thought E is a state function, so it should not matter how I reached from initial to final state. If it's an ideal gas, then for same P and V I must get same T, regardless of any bath... What am I missing?
  3. O

    A simple question in thermodynamics

    I'm sure there are more than two ways, but I'm asking about these two. First is to relase the piston at once (getting a new constant external pressure). Second is to release it in very small steps (thus temprature remains constant). As far as I see we have the same Ef and Ei, because it should...
  4. O

    A simple question in thermodynamics

    I have a cylinder with gas in it. I can make it expand in two ways: spontaneously isobaric process or reversible isothermal process. I understand W and Q for each process are different, but is ΔE the same? If not - why?
  5. O

    Name the following molecule (common name and IUPAC)?

    I would need to know iso, sec and tert for my exam.. Some answers you should pick appear as iso\sec\tert rather than IUPAC formal names.. I wish it wasn't like that
  6. O

    Name the following molecule (common name and IUPAC)?

    Why not? Here is sec-butylcyclohexane: And another carbon to the chain simply makes it pentyl, am I wrong?
  7. O

    Name the following molecule (common name and IUPAC)?

    any iso/sec/tert name for it?
  8. O

    Name the following molecule (common name and IUPAC)?

    http://img43.imageshack.us/img43/2916/95953925.jpg [Broken] I understand molecule #1 is sec-pentylcyclohexane But how would you call molecule 2? Please give common and IUPAC names (no need for too much detailed explainations) Thank you.
  9. O

    Discrete math - simple formalism question

    Hi gustav Thanks for your reply Could you just explain what "s.t." means? I'm not very familiar with the english terms. Thanks a bunch
  10. O

    Discrete math - simple formalism question

    I never used descrete math terms in english before, so I hope it sounds clear enough: Formalize the following: 1) Between every two different real numbers there is a rational number 2) There exist real numbers x and y, such that x is smaller than y, yet x^2 is bigger than y^2 Now the solution...
  11. O

    Linear Algebra - Jordan form basis

    OK, please discard all of my question, I'm an idiot :) Everything is clear now, I thank you very much for the last time :)
  12. O

    Linear Algebra - Jordan form basis

    Oh ok, I discard my 3rd question... The answer is that I pick v2 to be \begin{pmatrix} 1 \\ -1 \\ 1 \\ -1 \end{pmatrix} Now I remain only with questions 1, and 2.. More related to equations system rather than J form I suppose
  13. O

    Linear Algebra - Jordan form basis

    Hmm, ok I see what you say.. So now I have 3 final questions to close this case for good: 1) I thought all solutions were given by span of \begin{pmatrix} 1 \\ 0 \\ 1 \\ -2 \end{pmatrix} , \begin{pmatrix} 0 \\ 1 \\ 0 \\ -1 \end{pmatrix} So where did this \begin{pmatrix} 0 \\ 0 \\ 0 \\ 1...
  14. O

    Linear Algebra - Jordan form basis

    Ok, so I asked our instructor about the second question and yes, both methods are good. I prefer "my" method, but as you can see I still get stucked with it.. So how do I move on with this (A-3I)v_3 = λv_2+μv_4 ? Thanks again
  15. O

    Linear Algebra - Jordan form basis

    Hi, thanks for your kind replies. Ok, first I try what you suggested.. I take (A-3I)v_3 = λv_2+μv_4 I get: \begin{pmatrix} 1 & 1 & 1 & 1 \\ -1 & -1 & -1 & -1 \\ 6 & 1 & -4 & 1 \\ -6 & -1 & 4 & -1 \end{pmatrix}\begin{pmatrix} x \\ y \\ z \\ w \end{pmatrix}=\begin{pmatrix} λ \\ μ \\ λ \\...
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