SATHEE: Extraction of Metals - Result Question 88

Extraction of Metals - Result Question 88

####91. Answer the following questions briefly

(i) What is the actual reducing agent of haematite in blast furnace?

(ii) Give the equation for the recovery of lead from galena by air reduction.

(iii) Why is sodium chloride added during electrolysis of fused anhydrous magnesium chloride?

(iv) Zinc, not copper is used for the recovery of metallic silver from complex ${[A g (C N)_{2}]}^{-}$ , explain

(v) Why is chalcocite roasted and not calcinated during recovery of copper?

$(1987, 5 M)$

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Solution:

(i) Carbon monoxide :

(ii)

$\begin{aligned} C + O_{2} & ⟶ C O C O + F e_{2} O_{3} & ⟶ C O_{2} + F e 2 P b S + 3 O_{2} & ⟶ 2 P b O + 2 S O_{2} 2 P b O + P b S & ⟶ 3 P b + S O_{2} \end{aligned}$

(iii) To improve electrical conductivity of melt.

(iv) A metal which is much more electropositive than $A g$ can only replace $A g^{+}$ completely from ${[A g (C N)_{2}]}^{-}$ as

$Z n + 2 [A g (C N)_{2} ⌉ ⟶ {[Z n (C N)_{4}]}^{2 -} + 2 A g$

(v) Chalcocite is a sulphide ore of copper, during roasting, $S O_{2}$ is liberated, which is not possible in calcination.

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अगला

Extraction of Metals - Result Question 88

Solution:

इंजीनियरिंग की तैयारी

चिकित्सा तैयारी

एनसीईआरटी पुस्तकें और समाधान

महत्वपूर्ण संसाधन

अन्य संसाधन

पाठ्यक्रम

परीक्षा मंच

नमूना मॉक टेस्ट

सदस्यता

एनसीईआरटी व्यायाम वीडियो समाधान

Extraction of Metals - Result Question 88

Solution:

इंजीनियरिंग की तैयारी

चिकित्सा तैयारी

एनसीईआरटी पुस्तकें और समाधान

महत्वपूर्ण संसाधन

अन्य संसाधन

पाठ्यक्रम

परीक्षा मंच

नमूना मॉक टेस्ट

सदस्यता

एनसीईआरटी व्यायाम वीडियो समाधान

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