19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Assertion: Cryolite is used in electrolytic extraction of Al from alumina. Reason: It dissolves alumina.
Assertion: CuFeS₂ is concentrated by froth floatation method. Reason: CuFeS₂ is main ore of copper.
Assertion: In the electrolytic reduction of Al₂O₃, cryolite is used. Reason: Cryolite is an ore of aluminium.
Assertion: Wrought iron is more malleable and ductile than steel. Reason: It contains slightly less percentage of carbon.
Assertion: Lead, tin and bismuth are purified by liquation method. Reason: Lead, tin and bismuth have low m.p. as compared to impurities.
Assertion: Al₂O₃ is converted into Al by reduction with carbon at high temp. Reason: Carbon has greater affinity for oxygen than aluminium.
Assertion: All the ores are mineral. Reason: Ores contains metals in combined state
The chemical composition of ‘slag’ formed during the smelting process in the extraction of copper is
Boron can be obtained by various methods but not by:
Select correct statement:
Which of the following factors is of no significance for roasting sulphide ores to the oxides and not subjecting the sulphide ores to carbon reduction directly
Formation of metallic copper from the sulphide ore in the commercial metallurgical process involves. (a) Cu S⁺ O Cu O+SO ; Cu O+C 2Cu+CO → → (b) Cu S O Cu O SO ; 2Cu O Cu S 6Cu SO → → (c) Cu S 2O CuSO ; CuSO Cu S 3Cu …
Which of the following pair of ores cannot be converted into corresponding metals by pyrometallurgy?
The methods chiefly used for the extraction of lead and tin from their ores are respective
Refining of impure copper with zinc impurity is to be done by electrolysis using electrodes as Cathode Anode
Which of the following reactions does not occur in Bessemer converter in the extraction of copper from chalcopyrites?
Silver is extracted from its native ore by:
Which of the following is not correctly matched?
Assertion: In the electrolytic reduction of Al₂O₃, cryolite is used. Reason: Cryolite is an ore of aluminium.
The chemical composition of ‘slag’ formed during the smelting process in the extraction of copper is
Boron can be obtained by various methods but not by:
Select correct statement:
Which of the following factors is of no significance for roasting sulphide ores to the oxides and not subjecting the sulphide ores to carbon reduction directly
Formation of metallic copper from the sulphide ore in the commercial metallurgical process involves. (a) Cu S⁺ O Cu O+SO ; Cu O+C 2Cu+CO → → (b) Cu S O Cu O SO ; 2Cu O Cu S 6Cu SO → → (c) Cu S 2O CuSO ; CuSO Cu S 3Cu …
Which of the following pair of ores cannot be converted into corresponding metals by pyrometallurgy?