Two statements are given below: Statement I: Molten NaCl is electrolysed using Pt electrodes. \( Cl_2 \) is liberated at the anode.
Statement II: Aqueous CuSO\(_4\) is electrolysed using Pt electrodes. \( O_2 \) is liberated at the cathode. The correct answer is:
Statement I is not correct but statement II is correct
Step 1: Understanding Electrolysis of Molten NaCl
- When molten sodium chloride (\( NaCl \)) is electrolysed using platinum electrodes, it undergoes the following reactions:
- At the cathode (\( - \)): \( Na^+ + e^- \rightarrow Na \) (Sodium metal is deposited)
- At the anode (\( + \)): \( 2Cl^- \rightarrow Cl_2 + 2e^- \) (Chlorine gas is liberated)
- Therefore, Statement I is correct since \( Cl_2 \) is indeed liberated at the anode.
Step 2: Understanding Electrolysis of Aqueous CuSO\(_4\)
- When aqueous copper sulfate (\( CuSO_4 \)) is electrolysed using platinum electrodes:
- At the cathode: \( Cu^{2+} + 2e^- \rightarrow Cu \) (Copper is deposited)
- At the anode: \( 2H_2O \rightarrow O_2 + 4H^+ + 4e^- \) (Oxygen gas is liberated)
- However, the oxygen gas is liberated at the anode, not at the cathode, making Statement II incorrect.
Step 3: Evaluating the Given Options
- Option (1): Incorrect, because Statement II is incorrect.
- Option (2): Incorrect, as Statement I is correct.
- Option (3): Correct, as Statement I is correct, and Statement II is incorrect.
- Option (4): Incorrect, as Statement I is correct.
Thus, the correct answer is
Option (3).
| Molisch's lest | Barfoed Test | Biuret Test | |
|---|---|---|---|
| A | Positive | Negative | Negativde |
| B | Positive | Positive | Negative |
| C | Negative | Negative | Positive |
A current of 15.0 amperes is passed through a solution of CrCl2, for 45 minutes. The volume of Cl2 , (in I) obtained at the anode at 1 atm and 273 K is around (IF=96500 Cmol-1, At. wt. of Cl=35.5, R=0.082 L-atmK-1 mol-1)
The standard electrode potentials \( E^\circ (V) \) for \( Li^+/Li \), \( Na^+/Na \) respectively are:
(1) −3.04, −2.714
(2) −2.714, −3.04
(3) −3.04, −3.04
(4) −2.714, −2.714
Which of the following statements are correct?
i) \( CCl_4 \) undergoes hydrolysis easily.
(ii) Diamond has directional covalent bonds.
(iii)Fullerene is the thermodynamically most stable allotrope of carbon.
(iv)Glass is a man-made silicate.