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Chemistry: Post your doubts here!

Discussion in 'International A And AS Level' started by XPFMember, Sep 29, 2011.

  1. MShaheerUddin

    MShaheerUddin

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    Bro what this 1 represent in ratio "1"/0.174
     
    Last edited: Feb 5, 2018
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  3. MShaheerUddin

    MShaheerUddin

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    Corona
    Bro Can You tell me How can element Calcium have giant structure?
     
  4. corona

    corona

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    The question asks for the ratio of masses of Gas X to Gas Y, but 0.174 is the ratio of masses of Gas Y to Gas X.
    Hence, we reciprocate it.
     
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  5. corona

    corona

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    Metals generally are, on an atomic scale, giant structures in which electrons in the outer shells of the metal atoms are free to move.

    Edit:
    Reference: https://www.chemguide.co.uk/atoms/structures/metals.html
     
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  6. MShaheerUddin

    MShaheerUddin

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    OMG Thanks!
     
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  7. MShaheerUddin

    MShaheerUddin

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  8. Metanoia

    Metanoia

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    50 cm^3 of CH4 will react with 100 cm^3 of oxygen to produce 50 cm^3 of CO2 and water

    Immediately after the reaction, we will have mixture of 50 cm^3 of CO2 and 50 cm^3 of O2 (excess unreacted)

    The acidic CO2 would be absorbed by the KOH (alkali) leaving only 50 cm^3 of O2 in the tube
     
  9. Unknown202

    Unknown202

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    Can someone explain wht is meant by
    34 Which statements correctly describe an effect of a rise in temperature on a gas-phase reaction?
    1 More particles now have energies greater than the activation energy.
    2 The energy distribution profile changes with more particles having the most probable energy.
    3 The activation energy of the reaction is decreased.
    The one marked in red ik the answer is 1 but I want to understand 2 plzz help
     
  10. Unknown202

    Unknown202

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    Ammonia is made by the Haber process. The reactants are nitrogen and hydrogen.
    N2(g) + 3H2(g) 2NH3(g) ∆H –ve
    What will increase the rate of the forward reaction?
    A adding argon to the mixture but keeping the total volume constant
    B decreasing the temperature
    C increasing the total pressure by reducing the total volume at constant temperature
    D removing ammonia as it is made but keeping the total volume of the mixture the same
    And these one B and C both seem correct ?!
     
  11. Prasannadhungel4

    Prasannadhungel4

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    can we carry forward our winter 2017 chemistry grades to next winter 2018.
     
  12. Hamnah Zahoor

    Hamnah Zahoor

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    This will favour the forward reaction but will not increase the rate...less energy in reacting particles.
     
  13. studyingrobot457

    studyingrobot457

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  14. RockstarRifat

    RockstarRifat

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    9701/12/O/N/15 Q-39
    I am not able to understand how to figure out whether one or many products are formed?
     

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  15. Hamnah Zahoor

    Hamnah Zahoor

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    Energy distribution profile refers to the profile showing the ethalpy change of a reaction and Activation energy of the reaction ...increasing the temperature will not effect it both will remain the same ......the statement is a bit confusing though.
     
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  16. Metanoia

    Metanoia

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    Capture.JPG

    The 'most probable energies' at a specific temperatures are the respective peaks
    When temperature increases, the peak is lowered, thus less particles will have the most probable energy
     
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  17. Prometheus Gomes

    Prometheus Gomes

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    9701_s13_qp12 question 21,24,25,26
     

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  18. Bhuvana123

    Bhuvana123

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    The answer is B because the forward reaction is exothermic and a decrease in temperature will favor the forward reaction. if there is an increase in temperature it will favor the reverse reaction which is endothermic.
     
  19. Bhuvana123

    Bhuvana123

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    Hey please tell me if you get the answer
     
  20. Unknown202

    Unknown202

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    So doesn't it if to be C
     
  21. Unknown202

    Unknown202

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    mustafa4000 and Bhuvana123 like this.

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