Advertisements
Advertisements
प्रश्न
Explain the concept of Roasting.
Advertisements
उत्तर
In roasting process, the sulphide ores are strongly heated in air to transform them into oxides. In this process, sulphide ores are oxidized to form metal oxides and sulphur dioxide gas.
APPEARS IN
संबंधित प्रश्न
In the extraction of aluminium: Name the process of concentration of bauxite.
Silver metal does not combine easily with oxygen but silver jewellery tarnishes after some time. How?
Describe with one example, how moderately reactive metals (which are in the middle of reactivity series) are extracted.
Name the chemical compound which is electrolysed in molten state to obtain sodium metal. Which gas is produced in this process?
Name one ore of sodium. Name the sodium compound present in this ore and write its chemical formula.
How is sodium metal extracted? Explain with the help of equation of the reaction involved.
The metal which can be extracted simply by heating the cinnabar ore in air is:
(a) Zn
(b) Cu
(c) Al
(d) Hg
Rock salt is an ore of one of the following metals. This metal is:
(a) Mn
(b) Na
(c) Fe
(d) Cu
When an object made of metal A is kept in air for a considerable time, it loses its shine and becomes almost black due to the formation of a layer of substance B. When an object made of another metal C is kept in damp air for a considerable time, it gets covered with a green layer of substance D. Metal A is the best conductor of electricity whereas metal C is the next best conductor of electricity.
(a) What is metal A?
(b) What is metal C?
(c) Name the substance B.
(d) Name the substance D.
A black metal oxide XO2 is used as a catalyst in the preparation of oxygen gas from potassium chlorate. The oxide XO2 is also used in ordinary dry cells. The metal oxide XO2 cannot be reduced satisfactorily with carbon to form metal X.
(a) Name the metal X.
(b) Name the metal oxide XO2.
(c) Which reducing agent can be used to reduce XO2 to obtain metal X?
(d) Name another metal which can also be extracted by the reduction of its oxide with the above reducing agent.
Define the term:
Slag
Explain the following:
Galvanization protects iron from rusting.
Compare the properties of a typical metal and a non- metal on the basis of the following:
(a) electronic configuration
(b) nature of oxides
(c) oxidizing or reducing action
(d) conductivity of heat and electricity
Correct the following statement :
Copper reacts with nitric acid to produce nitrogen dioxide.
Aluminium oxide is _______ oxide.
Gold and silver are active metals.
Explain the following reaction with the balanced equation.
Chlorine dissolved in water
Explain in brief types of extraction of less reactive metals according to their reactivity.
Why should the metal sulphides and carbonates be converted to metal oxides in the process of extraction of metal from them?
