Science (English Medium) Class 12 - CBSE Question Bank Solutions for Chemistry

Which of the following features are not shown by quartz glass?

(i) This is a crystalline solid.

(ii) Refractive index is same in all the directions.

(iii) This has definite heat of fusion.

(iv) This is also called super cooled liquid.

Under which situations can an amorphous substance change to crystalline form?

Electrode potential for Mg electrode varies according to the equation

`E_(Mg^(2+)  |  Mg) = E_(Mg^(2+)  |  Mg)^Θ - 0.059/2 log  1/([Mg^(2+)])`. The graph of `E_(Mg^(2+)  |  Mg)` vs `log [Mg^(2+)]` is ______.

Which of the following statement is correct?

Which of the following statement is not correct about an inert electrode in a cell?

An electrochemical cell can behave like an electrolytic cell when ______.

Use the data given in below find out which option the order of reducing power is correct.

`"E"_("Cr"_2"O"_7^(2-)//"Cr"^(3+))^⊖`= 1.33 V `"E"_("Cl"_2//"Cl"^-)^⊖` = 1.36 V

`"E"_("MnO"_4^-//"Mn"^(2+))^⊖` = 1.51 V `"E"_("Cr"^(3+)//"Cr")^⊖` = - 0.74 V

Use the data given in below find out the most stable ion in its reduced form.

`"E"_("Cr"_2"O"_7^(2-)//"Cr"^(3+))^⊖`= 1.33 V `"E"_("Cl"_2//"Cl"^-)^⊖` = 1.36 V

`"E"_("MnO"_4^-//"Mn"^(2+))^⊖` = 1.51 V `"E"_("Cr"^(3+)//"Cr")^⊖` = - 0.74 V

Use the data given in below find out the most stable oxidised species.

`E^0 (Cr_2O_1^(2-))/(Cr_(3+))` = 1.33 V   `E^0 (Cl_2)/(Cl^-)` = 1.36 V

`E^0 (MnO_4^-)/(MN^(2+))` = 1.51 V   `E^0 (Cr^(3+))/(Cr)` = – 0.74 V

The quantity of charge required to obtain one mole of aluminium from Al₂O₃ is ______.

`E_(cell)^Θ` for some half cell reactions are given below. On the basis of these mark the correct answer.

(a) \[\ce{H^{+} (aq) + e^{-} -> 1/2 H_2 (g); E^Θ_{cell} = 0.00V}\]

(b) \[\ce{2H2O (1) -> O2 (g) + 4H^{+} (aq) + 4e^{-}; E^Θ_{cell} = 1.23V}\]

(c) \[\ce{2SO^{2-}_{4} (aq) -> S2O^{2-}_{8} (aq) + 2e^{-}; E^Θ_{cell} = 1.96V}\]

(i) In dilute sulphuric acid solution, hydrogen will be reduced at cathode.

(ii) In concentrated sulphuric acid solution, water will be oxidised at anode.

(iii) In dilute sulphuric acid solution, water will be oxidised at anode.

(iv) In dilute sulphuric acid solution, \[\ce{SO4^{2-}}\] ion will be oxidised to tetrathionate ion at anode.

`E_(cell)^Θ` = 1.1V for Daniel cell. Which of the following expressions are correct description of state of equilibrium in this cell?

(i) 1.1 = `K_c`

(ii) `(2.303RT)/(2F) logK_c` = 1.1

(iii) `log K_c = 2.2/0.059`

(iv) `log K_c` = 1.1

For the given cell, \[\ce{Mg | Mg^{2+} || Cu^{2+} | Cu}\]

(i) \[\ce{Mg}\] is cathode

(ii) \[\ce{Cu}\] is cathode

(iii) The cell reaction is \[\ce{Mg^+ Cu^{2+} -> Mg^{2+} + Cu}\]

(iv) \[\ce{Cu}\] is the oxidising agent

Can absolute electrode potential of an electrode be measured?

Depict the galvanic cell in which the cell reaction is \[\ce{Cu + 2Ag^+ -> 2Ag + Cu^{2+}}\]

What is electrode potential?

Consider the following diagram in which an electrochemical cell is coupled to an electrolytic cell. What will be the polarity of electrodes ‘A’ and ‘B’ in the electrolytic cell?

A galvanic cell has electrical potential of 1.1V. If an opposing potential of 1.1V is applied to this cell, what will happen to the cell reaction and current flowing through the cell?

How will the pH of brine (aq. \[\ce{NaCl}\] solution) be affected when it is electrolysed?

Consider a cell given below:
\[\ce{Cu | Cu^{2+} || Cl^{-} | Cl_{2},Pt}\]
Write the reactions that occur at anode and cathode