The method of zone refining of metals is based on the principle of
Options
(a) greater mobility of the pure metal than that of the impurity (b) higher melting point of the impurity […]
Silver is present in
Options
(a) limonite (b) magnetite (c) galena (d) dolomite
Correct Answer:
galena
Explanation:
No explanation available. Be the first to write the explanation for this question by commenting […]
The role of cryolite in the metallurgy of extraction of aluminium is to
Options
(a) increase the conductivity of the electrolyte (b) decrease the melting point of electrolyte (c) both (increases the conductivity […]
Pyrolusite is an ore of
Options
(a) manganese (b) tin (c) lead (d) polonium
Correct Answer:
manganese
Explanation:
No explanation available. Be the first to write the explanation for this question by […]
Aluminium is extracted from alumina (Al₂O₃) by electrolysis of a molten mixture of
Options
(a) Al₂O₃ + HF + NaAlF₄ (b) Al₂O₃ + CaF₂ + NaAlF₄ (c) Al₂O₃ + Na₃AlF₆ + CaF₂ (d) […]
Mg is present in
Options
(a) chlorophyll (b) haemoglobin (c) vitamin-D (d) vitamin-B
Correct Answer:
chlorophyll
Explanation:
No explanation available. Be the first to write the explanation for this question by commenting […]
Method used for obtaining highly pure silicon, used as a semiconductor material, is
Options
(a) crystallization (b) zone refining (c) oxidation (d) electro-chemical
Correct Answer:
zone refining
Explanation:
No explanation available. […]
Roasting is done in
Options
(a) blast furnace (b) reverberatory furnace (c) electric furnace (d) refractory furnace
Correct Answer:
reverberatory furnace
Explanation:
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Calcination is used in metallurgy to remove
Options
(a) CO₂ and H₂S (b) H₂O and SiO₂ (c) H₂O and H₂S (d) H₂O and CO₂
Correct Answer:
H₂O and CO₂
Explanation:
No explanation available. […]
Colloidal solution of gold is prepared by
Options
(a) colloidal mill (b) double decomposition method (c) Bredig’s method (d) Peptization
Correct Answer:
Bredig’s method
Explanation:
No explanation available. Be the first to write […]
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