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Gchem

Discussion in 'DAT Discussions' started by Glycogen, Jun 20, 2008.

  1. Glycogen

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    1. Which of the following is the correct expression for the natural gas law?
    A. PT = nVR
    B. VR = nPT
    C. PV = nRT
    D. RT = nPV
    2. What is the boiling point of water at standard pressure on the Kelvin Scale?
    A. 272 K
    B. 273 K
    C. 372 K
    D. 373 K
    3. Which statement is consistent with the kinetic theory of ideal gases?
    A. Molecules transfer energy through collisions.
    B. Molecules are always stationary.
    C. The force of attraction between molecules is constant.
    D. The size of the molecules is large compared to the distance that separates them.
    4. Gas molecules at the same temperature are always assumed to have the same
    A. Uniform velocity
    B. Uniform acceleration
    C. Straight line motion
    D. Straight line motion
    E. Random motion
    5. As the volume of a fixed mass of an ideal gas increases at constant temperature, the product of the pressure and the volume of the gas
    A. Decreases
    B. Increases
    C. Remains the same
    6. Which property determines the direction of the exchange of internal energy between two objects?
    A. Temperature
    B. Specific Heat
    C. Mass
    D. Density
    7. A glass rod becomes positively charged when it is rubbed with silk. This net positive charge accumulates because the glass rod
    A. Gains electrons
    B. Gains protons
    C. Loses electrons
    D. Loses protons

    8.Because of its high reactivity, which element is never found free in nature?(For this Q would you also mention what are other high reactive elements?)

    A. O
    B. F
    C. N
    D. Ne
     
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  3. Orgodox

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  4. osimsDDS

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    nice
     
  5. harrygt

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    Good questions. THey say Gchem has got more conceptual this year.
     
  6. Glycogen

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    Ok, guys very well done.These are the answer to these Qs:
    1. C
    2. D
    3. A
    4. D
    5. C
    6. A
    7. C
    8. B

    Also,I would appreciate if you can tell me what are the high reactive elements! Halogens? I'm not sure about this.
    And one last Q,what would be the answer to this Qs,

    9. The physical expressions of a gene are known as an organism's:
    A. Transcription
    B. Genotype
    C. Phenotype
    D. Translation

    I thought,I got it right but the answer is not what I thought and I can see the reasoning behind it.I want to see your answers before I post the answer.Thank you all.
     
  7. osimsDDS

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    .
     
  8. harrygt

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    Can you please explain number 4? what is straight line motion? never heard of it.
    Halogens and alkali metals are the most reactive. You don't see most of them free in the environment.
    I would go with "Phenotype" for the last question. It is kind of a bad question though, one of those in which you have to read the designers mind. You might read it wrong. lol
     
  9. Glycogen

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    Well,I did not make those Qs and therefore have no explanation for #4 since I got RANDOM MOTION myself and I think it should be the right answer according to this definition:

    "random motion of particles in a fluid medium (gas or liquid) as they are subjected to impact from the molecules of the medium is known as Brownian movement.

    So,either the guy who created these Qs had some reasoning in his mind that we can not see it or this is a pure mistake!!!
    Regarding the other Q, the right answer is transcription!! and I too choose phenotype!
    I was thinking maybe b/c it says physical expression we had to pick transcription?!
    I don't know,what do you think?
     
  10. harrygt

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    That is a stupid question then. If there was no phenotype, I would choose "translation" . It says physical, so to me, it means we should choose a step that give the outcome of the expression. The outcome is usually a protein [In translation], and as we know, proteins are responsible for making the phenotype.
    What is the source of this question?
     
  11. DDSguyLA

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    See, this is a type of question they will never give you.

    Because it has two answers. You can choose phenotype and trancription...

    You could prob pick Translation as well if you look at the question differently.

    Is this from destroyer??


    Physical expressions are Phenotypes and those physical expressions come your genes physical expression which is transcription because that is where you Information for the actual phenotype is store...
     
  12. DRHOYA

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    1. Which of the following is the correct expression for the natural gas law?
    A. PT = nVR
    B. VR = nPT
    C. PV = nRT
    D. RT = nPV
    2. What is the boiling point of water at standard pressure on the Kelvin Scale?
    A. 272 K
    B. 273 K
    C. 372 K
    D. 373 K
    3. Which statement is consistent with the kinetic theory of ideal gases?
    A. Molecules transfer energy through collisions.
    B. Molecules are always stationary.
    C. The force of attraction between molecules is constant.
    D. The size of the molecules is large compared to the distance that separates them.
    4. Gas molecules at the same temperature are always assumed to have the same
    A. Uniform velocity
    B. Uniform acceleration
    C. Straight line motion
    D. Straight line motion
    E. Random motion
    5. As the volume of a fixed mass of an ideal gas increases at constant temperature, the product of the pressure and the volume of the gas
    A. Decreases
    B. Increases
    C. Remains the same
    6. Which property determines the direction of the exchange of internal energy between two objects?
    A. Temperature
    B. Specific Heat
    C. Mass
    D. Density
    7. A glass rod becomes positively charged when it is rubbed with silk. This net positive charge accumulates because the glass rod
    A. Gains electrons
    B. Gains protons
    C. Loses electrons
    D. Loses protons

    8.Because of its high reactivity, which element is never found free in nature?(For this Q would you also mention what are other high reactive elements?)

    A. O
    B. F
    C. N
    D. Ne


    Cool test. I think I did ok. Are these type of questions considered "conceptual" gchem's?
     
  13. DRHOYA

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    Ahhh. I got 4 and 5 wrong. I understant the pressure and volume one (inversly proportional so if you increase volume you decrease pressure and the product would be the same)........but could you explain the straight line motion answer for 4???? I don't get that. Wouldn't thay also have the same velocity b/c heat is a measure of KE, and all the molecules are the same gas??? Thanks man.
     
  14. harrygt

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    DRHOYA, I did not get the straight line motion either. Never heard of it!
    About the velocity, not all the particles have the same velocity. There is an average velocity which you can calculate by the formula
    1/2 *m [mass of each particle] * V(average)^2 = 3/2*K[a const] * T [temp]
    But yeah, anyway all the particles don't have the average velocity. there is a bell shaped curve for the % of the molecules that are close to the average [a big portion] and the rest which are off the average.
     
  15. DRHOYA

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    Yeah ok that makes more sense. I understand the 1/2mv-squared equation. Also, I don't think the velocity vector for the overall gas would be uniform b/c all molecules are scattered............thats why the straight line motion one doesn't click.
     

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