Advertisements
Advertisements
प्रश्न
Define roasting.
Advertisements
उत्तर
Roasting is the process of heating concentrated ore to a high temperature in the presence of air. The process is usually carried out for sulphide ores.
संबंधित प्रश्न
Name a reducing agent that may be used to obtain manganese from manganese dioxide.
Write the composition of the alloy called bronze.
Give two uses of bronze.
Name two metals which are highly resistant to corrosion.
How are the less reactive metals (which are quite low in the reactivity series) extracted? Explain with the help of an example.
Explain given equation, what happens when ZnCO3 is heated in the absence of air?
Name the metal which is extracted from haematite ore.
Give the principles of the hydrolytic method.
Distinguish between ‘roasting’ and ‘calcination’. Which of these two is used for sulphide ores and why?
Define the following term.
Gangue
Answer the following questions based on the extraction of aluminium from alumina by Hall - Heroult’s Process :
Name the electrode, from which aluminium collected.
Name the following:
Name two metals always find in combined state.
How are metals refined by the electrolytic methods?
What is passive iron?
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
Answer the following question :
What is the difference between calcination and roasting.
Name the methods by which concentrated ore is converted to metallic oxide.
Define calcination.
Name the following :
The Process of heating an ore to a high temperature in the presence of air.
Name the process used for the enrichment of sulphide ore.
Zinc sulphide : Roasting : : zinc carbonate : _______
In the electrolytic method, a layer of highly active metal is applied to a less active metal.
Write the molecular formulae of the following compound.
Fluorspar
Explain the following reaction with the balanced equation.
Ferric oxide is reacted with aluminium.
Explain the following reaction with the balanced equation.
Dry aluminium hydroxide is ignited at 1000 °C
Complete flow chart given below.
Observe the figure and answer the following.
- Write the name of the method.
- What is used as anode and cathode in this method?
- Write the molecular formula and use of cryolite.
- Write anode reaction.
- Write cathode reaction.
Which of the following ore is concentrated by the Froth floatation process?
2 mL each of concentrated HCl, HNO3 and a mixture of concentrated HCl and concentrated HNO3 in the ratio of 3 : 1 were taken in test tubes labelled as A, B and C. A small piece of metal was put in each test tube. No change occurred in test tubes A and B but the metal got dissolved in test tube C respectively. The metal could be
Give the reaction involved during extraction of zinc from its ore by
- roasting of zinc ore
- calcination of zinc ore
