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(A) The extraction of gold and silver involves the formation of a soluble complex with $CN^{-}$ ions in the presence of air $(O_2)$.$4Au(s) + 8CN^{-}(

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Displacement of metal by some other metal from the complex ion

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(A) The extraction of gold and silver involves the formation of a soluble complex with $CN^{-}$ ions in the presence of air $(O_2)$.$4Au(s) + 8CN^{-}(aq) + 2H_2O(aq) + O_2(g) \rightarrow 4[Au(CN)_2]^{-}(aq) + 4OH^{-}(aq)$$2Ag(s) + 4CN^{-}(aq) + 2H_2O(aq) + O_2(g) \rightarrow 2[Ag(CN)_2]^{-}(aq) + 4OH^{-}(aq)$The metal is then recovered from the complex by displacement using a more electropositive metal like zinc $(Zn)$:$2[Au(CN)_2]^{-}(aq) + Zn(s) \rightarrow [Zn(CN)_4]^{2-}(aq) + 2Au(s)$$2[Ag(CN)_2]^{-}(aq) + Zn(s) \rightarrow [Zn(CN)_4]^{2-}(aq) + 2Ag(s)$Thus,the correct method is the displacement of the metal by some other metal from the complex ion.

Extraction of gold and silver involves leaching the metal with $CN^{-}$ ion. The metal is recovered by . . . . . .

Similar Questions

In the extraction of copper,metal is formed in the Bessemer converter due to the reaction:

The compound$(s)$ that is(are) removed as slag during the extraction of copper is:
$1. CaO$
$2. FeO$
$3. Al_{2}O_{3}$
$4. ZnO$
$5. NiO$
Choose the correct answer from the options given below.

In the extraction of copper,metal is formed in the Bessemer converter due to the reaction:

Smelting is carried out in a ...... .

Which of the following elements has the lowest tendency to form its oxide?

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Extraction of gold and silver involves leaching the metal with $CN^{-}$ ion. The metal is recovered by . . . . . .

Similar Questions

In the extraction of copper,metal is formed in the Bessemer converter due to the reaction:

The compound$(s)$ that is(are) removed as slag during the extraction of copper is:$1. CaO$$2. FeO$$3. Al_{2}O_{3}$$4. ZnO$$5. NiO$Choose the correct answer from the options given below.

In the extraction of copper,metal is formed in the Bessemer converter due to the reaction:

Smelting is carried out in a ...... .

Which of the following elements has the lowest tendency to form its oxide?

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The compound$(s)$ that is(are) removed as slag during the extraction of copper is:
$1. CaO$
$2. FeO$
$3. Al_{2}O_{3}$
$4. ZnO$
$5. NiO$
Choose the correct answer from the options given below.