Self Studies
Self Studies
Self Studies
Self Studies

General Princip...

TIME LEFT -
  • Question 1
    1 / -0

    Directions For Questions

    Questions given below are based on the given diagram for extraction metallurgy.
    The points noted by arrows are the melting and boiling points of the metals zinc and magnesium. $$\Delta G^{\small\circ}$$ is a function of temperature for some reactions and extractive metallurgy.

    ...view full instructions

    At  $$1000^oC$$, $$\Delta G^{\small\circ}$$ of the reaction is:
    $$ZnO + C \longrightarrow Zn + CO$$

  • Question 2
    1 / -0

    Directions For Questions

    Questions given below are based on the given diagram for extraction metallurgy.
    The points noted by arrows are the melting and boiling points of the metals zinc and magnesium. $$\Delta G^{\small\circ}$$ is a function of temperature for some reactions and extractive metallurgy.

    ...view full instructions

    To make the following reduction process spontaneous, temperature should be
    $$ZnO + C \longrightarrow ZN + CO$$

  • Question 3
    1 / -0

    Directions For Questions

    The Ellingham diagram for a number of metallic sulphides is shown below :

    ...view full instructions


    Which sulphide occurs to minimum extent in nature?

  • Question 4
    1 / -0

    Directions For Questions

    The Ellingham diagram for a number of metallic sulphides is shown below :

    ...view full instructions


    Formation of which of the sulphides is most spontaneous?

  • Question 5
    1 / -0

    Directions For Questions

    For a spontaneous reaction, the free energy change must be negative.                                    
                          
                                  $$\Delta G=\Delta H- T $$ $$\Delta S$$ 

    $$\Delta$$$$H$$ is the enthalpy change during the reaction. $$T$$ is the absolute temperature, and $$\Delta$$$$S$$ is the change in entropy during the reaction. Consider a reaction such as the formation of an oxide. 

                                   $$M+O_{2}$$ $$\rightarrow$$ $$MO$$ 

    Dioxygen is used up in the course of this reaction. Gases have a more random structure (less ordered) than liquid or solids. Consequently, gases have a higher entropy than liquids and solids. In this reaction, $$S$$ (entropy or randomness) decreases, hence $$\Delta$$S is negative. Thus, if the temperature is raised then $$T\Delta$$S becomes more negative. Since $$T\Delta$$S is subtracted in the equation, then $$\Delta$$G becomes negative. 

    Thus, the free energy change increases with the increase in temperature. The free energy changes that occur when one mole of common reactant (in this case dioxygen) is used may be plotted graphically against temperature for a number of reactions of metals to their oxides. The following plot is called an Ellingham diagram for metal oxide. Understanding of Ellingham diagram is extremely important for the efficient extraction of metals

    ...view full instructions

    As per the Ellingham diagram of oxides which of the following conclusion is true?

  • Question 6
    1 / -0

    When $$FeCr_2O_4$$ (chromite) is reduced with Carbon in an electric-arc furnace:

  • Question 7
    1 / -0

    Directions For Questions

    The Ellingham diagram for a number of metallic sulphides is shown below :

    ...view full instructions


    Which of the following sulphides can not be reduced to metal by $$H_2$$ at about $$1000^{\small\circ}C$$?

  • Question 8
    1 / -0

    Directions For Questions

    For a spontaneous reaction, the free energy change must be negative.                                    
                          
                                  $$\Delta G=\Delta H- T $$ $$\Delta S$$ 

    $$\Delta$$$$H$$ is the enthalpy change during the reaction. $$T$$ is the absolute temperature, and $$\Delta$$$$S$$ is the change in entropy during the reaction. Consider a reaction such as the formation of an oxide. 

                                   $$M+O_{2}$$ $$\rightarrow$$ $$MO$$ 

    Dioxygen is used up in the course of this reaction. Gases have a more random structure (less ordered) than liquid or solids. Consequently, gases have a higher entropy than liquids and solids. In this reaction, $$S$$ (entropy or randomness) decreases, hence $$\Delta$$S is negative. Thus, if the temperature is raised then $$T\Delta$$S becomes more negative. Since $$T\Delta$$S is subtracted in the equation, then $$\Delta$$G becomes negative. 

    Thus, the free energy change increases with the increase in temperature. The free energy changes that occur when one mole of common reactant (in this case dioxygen) is used may be plotted graphically against temperature for a number of reactions of metals to their oxides. The following plot is called an Ellingham diagram for metal oxide. Understanding of Ellingham diagram is extremely important for the efficient extraction of metals

    ...view full instructions

    Which of the following elements can be prepared by heating the oxide above $$400^{o}C $$?

  • Question 9
    1 / -0

    Si of  high purity to be used in semiconductor can be prepared  by following methods :

    I. $$SiO_2\, +\, 2C\, \rightarrow\, Si\, +\, 2CO$$

    II. $$Si\, +\, 2Cl_2\, \rightarrow\, SiCl_4$$

    $$SiCl_4\, +\, 2Mg\, \rightarrow\, Si\, +\, 2MgCl_2$$

    Better method is :

  • Question 10
    1 / -0

    In electrtolysis of $$Al_2O_3$$ by Hall-Heroult process:

Submit Test
Self Studies
User
Question Analysis

  • Answered - 0

  • Unanswered - 10

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
Submit Test
Self Studies Get latest Exam Updates
& Study Material Alerts!
No, Thanks
Self Studies
Click on Allow to receive notifications
Allow Notification
Self Studies
Self Studies Self Studies
To enable notifications follow this 2 steps:
  • First Click on Secure Icon Self Studies
  • Second click on the toggle icon
Allow Notification
Get latest Exam Updates & FREE Study Material Alerts!
Self Studies ×
Open Now