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Answer the questions on the following passage.
The minerals from which the metal can be separated economically are called ores. Ores contain many types of impurities such as soil, sand and rocky substances along with metal compounds. These impurities are called gangue.
Metals can be extracted from their ores by means of various methods of separation. The process of extraction of metal in a pure state from the ores is also a part of metallurgy.
Ores are taken out from the mines and the gangue is usually separated from the ore at the site itself by various methods. Then the ores are carried out to the place where metals are produced. Here metals are extracted in pure form. Then metals are further purified by different methods of purification. This entire process is called metallurgy. Most metals being reactive do not occur in nature in the free state but are found in combined state as their salts such as oxides, carbonates, sulphides, and nitrates. however, the most unreactive metals that are not affected by air, water and other natural factors like silver, gold, platinum, generally occur in a free state. The compounds of metals that occur in nature along with the impurities are called minerals.
- What are ores?
- Which processes are involved in the branch of metallurgy? What is metallurgy?
- Which metals are found in a free state?
- In what forms are metals found in combined state?
- What is gangue?
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Explain the difference between Bayer’s process and Hall’s process by explaining the Bayer’s process.
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Read the following paragraphs and write the answers.
Next to the moon, the astronomical object nearest to the earth is Mars. Many nations sent spacecrafts to Mars. Mars mission is difficult and almost half the missions were unsuccessful. However, ISRO’s performance in this mission is remarkable and we all must be proud of it. The spacecraft ‘Mangalyaan’ made by ISRO using minimum expenses was launched in November, 2013 and was placed into orbit around Mars in September, 2014. It obtained very useful information about the surface of Mars and the atmosphere around it.
- Next to the moon, which is the nearest celestial object to the earth?
- When did Mangalyaan placed into orbit around Mars by ISRO?
- What important information did ISRO's Mangalyaan obtain?
- Explain that critical velocity does not depend on the mass of the satellite.
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Identify the type of chemical reaction given below:
\[\ce{2Mg + O2 -> 2MgO}\]
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Identify the type of chemical reaction given below:
\[\ce{2KClO3 -> 2KCl + 3O2 ^}\]
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Correlate the given sequence:
Hypermetropia : Convex lens : ______ : Concave lens
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When hydrogen gas is passed over black copper oxide, a reddish-coloured layer of copper is formed.
Answer the questions that follow based on this reaction.
- Write the equation.
- What type of reaction is it?
- Complete the blanks:
In this reaction, an oxygen atom goes away from CuO (copper oxide), which means that ______ of copper oxide takes place, whereas a hydrogen molecule takes up an oxygen atom and water (H2O) is formed, meaning ______ of hydrogen takes place.
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Answer the questions based on the equation below:
\[\ce{CH3 - CH2 - OH ->[{[O]}][K2Cr2O7/H2SO4] CH3 - COOH}\]
- What type of reaction is it?
- What is the role of the chemical written on the arrow?
- Give one example of one such type of chemical as in answer (b).
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It is recommended to use air tight containers for storing oil for a long time.
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Observe the figure whether it is correct or not and explain the phenomenon.
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Complete the following table:
| Chemical Reactions | Name reaction type |
| \[\ce{C(s) + O2(g) -> CO2(g)}\] | (a) ________ |
| \[\ce{Zn(s) + CuSO4(aq) ->}\] (b) _________ | Displacement reaction |
| \[\ce{2Cu(s) + O2(g) ->[heat] 2CuO(s)}\] | (c) _________ |
| \[\ce{C(s) + 2H2(g) -> CH4(g)}\] | (d) _________ |
| \[\ce{CaO(s) + H2O(l) -> Ca(OH)2(aq) + heat}\] | (e) _________ |
| \[\ce{CaCO3(s) + Heat ->}\] (f) _________ | Endothermic Reaction |
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Observe the figure and answer the following questions:
- Name the defect of vision represented in the above figure.
- State the reasons for this defect.
- How is it corrected?
- Draw the diagram to show the correction of this defect.
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Give scientific reasons.
While preparing dilute sulphuric acid from concentrated sulphuric acid in the laboratory, the concentrated sulphuric acid is added slowly to water with constant stirring.
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Give a scientific reason.
While preparing dilute sulphuric acid from concentrated sulphuric acid in the laboratory, the concentrated sulphuric acid is added slowly to water with constant stirring.
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Give scientific reasons.
While preparing dilute sulphuric acid from concentrated sulphuric acid in the laboratory, the concentrated sulphuric acid is added slowly to water with constant stirring.
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Give scientific reasons.
While preparing dilute sulphuric acid from concentrated sulphuric acid in the laboratory, the concentrated sulphuric acid is added slowly to water with constant stirring.
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Give scientific reasons.
While preparing dilute sulphuric acid from concentrated sulphuric acid in the laboratory, the concentrated sulphuric acid is added slowly to water with constant stirring.
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Give scientific reason.
While preparing dilute sulphuric acid from concentrated sulphuric acid in the laboratory, the concentrated sulphuric acid is added slowly to water with constant stirring.
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Give scientific reasons.
While preparing dilute sulphuric acid from concentrated sulphuric acid in the laboratory, the concentrated sulphuric acid is added slowly to water with constant stirring.
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Complete the following table by observing the given figures:
| Figure → |  |
 |
| Points ↓ | ||
| (a) Name of the defect | ______ | ______ |
| (b) Position of the image | ______ | ______ |
| (c) Lens used to correct the defect | ______ | ______ |
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