Long Answer TypeWe know zinc has negative reduction potential [E° (Zn2+1 Zn) = –0 . 76V] and lies above hydrogen in the electrochemical series. Therefore, the electron accepting tendency of zinc is less than that of hydrogen or its electron releasing tendency is more.
Thus, zinc can lose electrons to H+ ions of the acid and as a result, hydrogen gas is liberated.
Since copper has a positive reduction potential (E° = +0.34 V) and lies below hydrogen in the electrochemical series, therefore, it cannot lose an electron to H+ ions of the acid. Hence H2 gas is not liberated.
Short Answer Type| Electrode |
Standard reduction potential (volts) |
| Cd2+ | Cd | –0.40 |
| Ni2+|Ni | –0.25 |
| 2H+|H2 | –0.00 |
| Cu2+ | Cu | + 0.34 |
| Ag+ | + Ag | +0.53 |
Long Answer TypeUsing the standard electrode potentials given in the Table 8.1, predict if the
reaction between the following is feasible:
(a) Fe3+ (aq) and I- (aq)
(b) Ag+(aq) and Cu(s)
(c) Fe3+(aq) and Cu(s)
(d) Ag(s) and Fe3+(aq)
(e) Br2(aq) and Fe2+(aq)
Predict the products of electrolysis in each of the following:
(i) An aqueous solution of AgNO3 with silver electrodes.
ii)An aqueous solution AgNO3 with platinum electrodes.
iii) A dilute solution of H2SO4 with platinum electrodes.
iv) An aqueous solution of CuCl2 with platinum electrodes.
Short Answer TypeDepict the galvanic cell in which the reaction Zn(s) + 2Ag+ (aq) → Zn2+(aq) +2Ag(s)
takes place, Further show:
(i) which of the electrode is negatively charged,
(ii) the carriers of the current in the cell, and
(iii) individual reaction at each electrode.
Multiple Choice QuestionsConsider the following reaction,
The values of x,y and z in the reaction are respectively
5,2 and 16
2,5 and 8
2,5 and 16
2,5 and 16
Which of the following chemical reactions depicts the oxidizing behaviour of H2SO4?
2HI+ H2SO4 →I2 +SO2+2HO
Ca(OH)2 +H2SO4 → CaSO4 +2H2O
NaCl +H2SO4 → NaHSO4 + HCl
NaCl +H2SO4 → NaHSO4 + HCl
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