ANSWER IN ONE SENTENCE

1. Name a metal used for wrapping chocolates and food stuff.

Ans. Aluminium is used for wrapping chocolates and food stuff.

2. Which chemical process is used for obtaining a metal from its oxide?

Ans. A chemical process reduction is used fro obtaining a metal from its oxide.

3. From which ore is aluminium extracted?

Ans. Aluminium is extracted from bauxite (Al₂O₃. 2H₂O)

4. Name the reducing agent which reduces the iron ore in the blast furnace.

Ans. Carbon monoxide reduces the iron ore in the blast furnace.

5. Name the nonmetal used as an electrode in an electrolytic cell.

Ans. Carbon, in the form of graphite is used as an electrode in an electrolytic cell.

6. Name the allotropes of sulphur.

Ans. Rhombic sulphur and monoclinic sulphur are allotropes of sulphur.

7. What does ammonia fountain experiment demonstrate?

Ans. Ammonia fountain experiment demonstrate the following

1. Ammonia gas is highly soluble in water.
2. It is basic in nature.

8. Name the main alloy of iron.

Ans. Steel is the main alloy of iron.

9. Name the main alloy of Aluminium.

Ans. Duralumin is the main alloy of Aluminium.

10. Name the most stable allotrope of sulphur at ordinary temperature.

Ans. Rhombic sulphur is the most stable allotrope of sulphur at ordinary temperature.

11. State the shapes of (i) Rhombic sulphur (ii) Monoclinic sulphur.

Ans. Rhombic sulphur is octahedral shaped. Monoclinic sulphur is needle shaped.

12. State the position of sulphur in the periodic table.

Ans. Sulphur belongs to the VIA group i.e. group 16 and the 3^rd period of the periodic table.

13. What is the sublimate of sulphur called?

Ans. The sublimate of sulphur is called flower of sulphur.

14. What is milk of sulphur?

Ans. Sulphur obtained by chemical reaction as precipitate is called milk of sulphur.

15. What are the components of gun powder?

Ans. Gun powder contains sulphur, charcoal and potassium nitrate.

16. Which two allotropes of sulphur are soluble in carbon disulphide?

Ans. Rhombic sulphur and monoclinic sulphur are two allotropes of sulphur which are soluble in carbon disulphide.

17. State the use of dry ice.

Ans. Dry ice is used as a coolant in storage.

18. Give one test to detect the presence of carbon dioxide.

Ans. Fresh lime water turns milky in the presence of carbon dioxide.

19. Name the method of collection of hydrogen sulphide gas.

Ans. Hydrogen sulphide gas is collected in a gas jar by the upward displacement of air.

20. Name the ores of iron.

Ans. Haematite (Fe₂O₃), Magnetite (Fe₃O₄), limonite (2Fe₂O₃.3H₂O) and siderite (FeCO₃) are the main ores of iron.

21. How is alloy prepared?

Ans. An alloy is prepared by melting the main metal, and then dissolving the other element in it in a specific proportion.

22. State the uses of steel?

Ans. Steels are used in Construction of ships, vehicles, bridges etc.

23. State the uses of stainless steel.

Ans. Stainless steel is used in Utensils, cutlery, automobile parts, surgical instruments etc.

24. State the uses of Tungsten steel.

Ans. Tungsten steel is used in High speed cutting tools.

25. State the uses of Manganese steel.

Ans. Manganese steel is used in rock drills.

26. State the uses of duralumin.

Ans. Duralumin is used in parts of sir of air crafts and buses, cooker, etc.

27. Name two alloys of iron.

Ans The alloys of iron are steel, stainless steel, tungsten steel etc.

28. Where does CO₂ occur in nature?

Ans. Carbon dioxide occurs in atmospheric air, caves and some minerals springs.

29. How does carbon dioxide released in the atmosphere?

Ans. Carbon dioxide is released in the atmosphere through burning of fuel, natural gases, respiration and fermentation.

30. How does carbon dioxide gas is collected?

Ans. Carbon dioxide gas is collected in a gas jar by the upward displacement of air.

31. Name the main ores of aluminium.

Ans. Bauxite (Al₂O₃.2H₂O) and Cryolite (AlF₃.3NaF) are the main ores of aluminium.