The metal always found in free state is

Which of the following benefaction processes is used for the mineral,Al₂O₃.2H₂O?

Consider the following reaction at 1000⁰C.
A.Zn(s)+\(1\over2\)O₂(g)\(\longrightarrow\)ZnO(g);\(\Delta\)G⁰=-360 kJ mol^-1
B.C(gr)+\(1\over2\)O₂(g)\(\longrightarrow\)CO(g);\(\Delta\)G⁰=-460 kJ mol^-1
Choose the correct statement at 1000⁰C

During smelting,an additional substance is added which combines with impurities to form a fusible mass.The additional substance is called

The method of zone refining of metals is based on the principle of 

Sodium cyanide solution is used to extract _____________or ________________from its ores.

_______________ act as an acidic flux while _______________ act as a basic flux.

_________________ involves reduction of metal oxide with coke or carbon monoxide.

Above 1073K, __________________ reduces FeO to Fe while below 1073K, ______________reduces FeO₃ to Fe.

________________is added to Al₂O₃ in Hall-Heroult for extraction of aluminium to ____________the melting point and to ___________ the electrical conductivity of the melt

What do you mean by benefaction process?

What is the role of a stabilizer in the froth floatation process?

what is the composition of copper matte?

What is the principle of zone refinijng?

What is role of flux in metallurgical processes?

Name one chief ore each of copper and aluminium. Name the method used for the concentration of these two ores.

Which of the ores of aluminium, iron, copper and zinc could be concentrated by magnetic method?

Name one example each of
(i) acidic flux
(ii) basic flux.

Why is external emf of more than 2.2 volt required for the extraction of Cl₂ from brine?

Although carbon and hydrogen are better reducing agents but they are not used to reduce metallic oxides at high temperatures, why?

Give two requirements for vapour phase refining.

Describe the role of the following:
(i) NaCN in the extraction of silver from a silver ore.
(ii) Iodine in the refining of titanium
(iii) Cryolite in the metallurgy of aluminium

What chemical principle is involved in choosing a reducing agent for getting the metal from its oxide ore? Consider the metal oxides, \(Al_{ 2 }{ O }_{ 3 }\) and \(Fe_{ 2 }{ O }_{ 3 }\), and justify the choice of reducing agent in each case.

Explain :
(i) zone refining
(ii) column chromatography.

What is the role of silicain the extraction of copper?

What are depressants? How would you separate Zinc sulphide (ZnS) and lead sulphide (PbS) ores?

While washing a miner's overalls, a washerwoman noticed that sand and similar dirt fell to the bottom of the washtub. What was peculiar, the copper-bearing compounds that had come to the clothes from the mines were caught in the soaplids and so they came to the top. One of her clients was a chemist, Mrs. Malik. The washerwoman told her experience to Mrs. Malik. The latter thought that the idea could be used for separating copper compounds from rocky and earth materials on a large scale. After reading the above passage answer the following questions-
What type of ores are concentrated by this process?

Metals are very useful in our daily life. Aluminium powder is used in white paints. It is also used as a reducing agent. Alloys containing aluminium being light, are very useful. Utensils of aluminium are more popular than utensils of brass. Metals like silver, gold, iron, copper, zinc are very useful in our daily life.
Why are aluminium vessels preferred over copper and bronze vessels?