Extraction of Metals - Result Question 55
####55. Match each of the reactions given in Column I with the corresponding product(s) given in Column II.
(2009)
| Column I | Column II | ||
|---|---|---|---|
| A. | $Cu+$ dil. $HNO _3$ | p. | $NO$ |
| B. | $Cu+$ conc. $HNO _3$ |
q. | $NO _2$ |
| C. | $Zn+$ dil. $HNO _3$ | r. | $N _2 O$ |
| D. | $Zn+$ conc. $HNO _3$ |
s. | $Cu\left(NO _3\right) _2$ |
| t. | $Zn\left(NO _3\right) _2$ |
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Solution:
- A. $3 Cu+8 HNO _3 \longrightarrow 3 Cu\left(NO _3\right) _2+2 NO+4 H _2 O$
Dil. B. $Cu+\underset{\text { Conc. }}{4 HNO _3} \longrightarrow Cu\left(NO _3\right) _2+2 NO _2+2 H _2 O$ C. $4 Zn+10 HNO _3 \longrightarrow 4 Zn\left(NO _3\right) _2+N _2 O+5 H _2 O$ Dil. D. $Zn+4 HNO _3 \longrightarrow Zn\left(NO _3\right) _2+2 NO _2+2 H _2 O$
B. $CaCO _3 \longrightarrow CaO+CO _2 \uparrow$; calcination
C. $ZnS \longrightarrow Zn$, can be done by carbon reduction or self reduction
| Extraction methods |
Metals extracted |
||
|---|---|---|---|
| A. | Self reduction | r. | Copper, (P) Lead |
| B. | Carbon reduction | p. | Lead |
| C. | Complex formation and displacement by metal |
q. | Silver : $Ag _2 S+NaCN$ $\longrightarrow Na\left[Ag(CN) _2\right]$ |
| $Na\left[Ag(CN) _2\right]+Zn$ $\longrightarrow Na _2\left[Zn(CN) _4\right]$ $+Ag$ |
|||
| D. | Decomposition of iodide |
s. | Boron : $BI _3 \stackrel{\Delta}{\longrightarrow} B+\frac{3}{2} I _2$ |
D. $Cu _2 S \longrightarrow Cu$, roasting followed by self reduction
