Extraction of Metals (At the middle of the activity Series) of Medium Reactivity:
The metals in the middle of the activity series as iron, zinc, lead, copper etc. are moderately reactive. These metals are usually present as sulphides or carbonates in nature. These sulphides or carbonates are first converted into oxides because it is easy to exact metals from its oxide. Sulphides are converted into oxides by roasting and carbonates are converted into oxides by calcinations. The metal oxides thus obtained are then reduced to the corresponding metals by reduction using suitable reducing agents such as carbon. Chemical Reactions involved in the extraction of zinc are as follows:
Roasting: It is the process in which sulphide ore is heated below its melting point in the presence of air to convert it into metal oxide. Sulphur impurities escape as gas.e.g.
Calcination: It is the process in which carbonate ore is heated below its melting point in the absence of air to convert it into metal oxide. For eg:
Reduction of oxide: It is the process of conversion of metal oxide ore into metal. It can be done by heating the oxides.Sometimes displacement reactions can also be used to reduce metal oxide.
The highly reactive metals such as sodium, calcium, aluminum etc, are used as reducing agents because they can displace metals of lower reactivity from their compounds, e.g. reaction of manganese dioxide with aluminum powder.
These displacement reactions are highly exothermic. The amount of heat produced is so high that the metals are produced in the molten state.The reaction of iron (III) oxide () with aluminum to produce iron is used to join railway tracks or cracked machine parts. This process is called thermite welding.
This reaction of metal oxide to form metal by using aluminum powder as a reducing agent is known as thermite reaction. The mixture of iron oxide and aluminium powder is called thermite.
Which of the following is a dehydrating agent ? | |||
Right Option : A | |||
View Explanation |
Which of the following are correct : (a) Sulphides are converted into oxides by roasting. (b) Carbonates are converted into oxides by calcinations. (c) The highly reactive metals such as sodium, calcium, aluminum etc, are used as reducing agents. | |||
Right Option : D | |||
View Explanation |
Which of the following metals cannot be extracted using smelting ? | |||
Right Option : B | |||
View Explanation |
Being a parent, I saw my daughter improvement in her studies by seeing a good result in all day to day compititive exam TMO, NSO, IEO etc and as well as studies. I have got a fruitful result from my daughter.
It was a good experience with Abhyas Academy. I even faced problems in starting but slowly and steadily overcomed. Especially reasoning classes helped me a lot.
Abhyas Methodology is very good. It is based on according to student and each child manages accordingly to its properly. Methodology has improved the abilities of students to shine them in future.
My experience was very good with Abhyas academy. I am studying here from 6th class and I am satisfied by its results in my life. I improved a lot here ahead of school syllabus.
One of the best institutes to develope a child interest in studies.Provides SST and English knowledge also unlike other institutes. Teachers are co operative and friendly online tests andPPT develope practical knowledge also.
It has a great methodology. Students here can get analysis to their test quickly.We can learn easily through PPTs and the testing methods are good. We know that where we have to practice
My experience with Abhyas is very good. I have learnt many things here like vedic maths and reasoning also. Teachers here first take our doubts and then there are assignments to verify our weak points.
My experience with Abhyas academy is very good. I did not think that my every subject coming here will be so strong. The main thing is that the online tests had made me learn here more things.
A marvelous experience with Abhyas. I am glad to share that my ward has achieved more than enough at the Ambala ABHYAS centre. Years have passed on and more and more he has gained. May the centre flourish and develop day by day by the grace of God.
I have spent a wonderful time in Abhyas academy. It has made my reasoning more apt, English more stronger and Maths an interesting subject for me. It has given me a habbit of self studying