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This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
How can prevent Corrosion of metal ? |
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Answer» Prevention of Corrosion Iron and steel (alloy of iron) are most easily protected by paint which provides a barrier between the metal and air/water. Moving parts on machines can be protected by a water repellent oil or grease layer. Covering the surface with enamel and lacquers is another method. Sacrificial Protection 'Rusting' can be prevented by connecting iron to a more reactive metal (e.g., zinc or magnesium). This is referred to as sacrificial protection or sacrificial corrosion, because the more reactive protecting metal is preferentially oxidized away, leaving the protected metal intact. Alloying Iron or steel along with other metals can also be protected by 'alloying' or mixing with other metals (e.g., chromium) to make non-rusting alloys. Stainless steel is an example of a nonrusting alloy of iron and carbon. Brass, an alloy containing copper is another metal alloy which is less expensive and non-reactive. Galvanizing Coating iron or steel with a thin zinc layer is called 'galvanizing'. This layer is produced by electrolytic deposition. Dipping the iron/steel object in molten zinc and using it as the negative cathode zinc is coated on it. Zinc preferentially corrodes or oxidizes to form a zinc oxide layer that does not flake off like iron oxide rust. Also, if the surface is scratched, the exposed zinc again corrodes before the iron and continues to protect it. Electroplating Coating the surface with metals like tin, chromium, nickel etc. by electroplating is also utilized to prevent corrosion. Steel cans are protected by relatively un-reacted tin and works well as long as the thin tin layer is complete. |
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| 2. |
Metals used in the preparation or ornaments and resistant to rust i) Mercury ii) Gold iii) Silver iv) Platinum A) ii and iv B) ii and iii C) ii, iii and iv D) i only |
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Answer» Correct option is A) ii and iv |
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| 3. |
Which of these metals are useful in preparation of jewellery? A) Gold B) Silver C) Copper D) All the above |
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Answer» Correct option is D) All the above |
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| 4. |
Ritika took four metals P, Q, R and S and added them to following solutions one by one. The results are summarised in the given table.Which of the following statements are correct? l. Q is more reactive than Fe but less reactive than Al. ll. Among the given metals, S is the most reactive metal. lll. R is less reactive than Ag but more reactive than Zn. lV. P is more reactive than Cu but less reactive than Fe.(A) I and lll only (B) ll and lV only (C) I and lV only (D) ll and lll only |
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Answer» Correct option (C) I and lV only Explanation: Q is the most reactive metal among the given elements. R is more reactive than Ag but less reactive than Zn. |
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| 5. |
Write chemical equations that shows aluminium oxide reacts with acid as well as base. |
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Answer» Al2O3 +6HCl→ 2AlCl3 +3H2O Al2O3 +2NaOH→ 2NaAlO2 +H2O |
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| 6. |
Copper sulphate + Zinc → Zinc sulphate + CopperCopper sulphate + Iron → Iron sulphate + CopperFerrous sulphate + Copper → No reactionFrom this experiment more reactive metal isA) CopperB) ZincC) IronD) None |
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Answer» Correct option is A) Copper |
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| 7. |
What are the Achievements of the Law of Octaves? |
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Answer» Achievements of the Law of Octaves • The law of octaves was the first logical attempt to classify elements on the basis of atomic weights. • Periodicity of elements was recognized for the first time. In 1860, there was a conference of chemists in Karl Sruhe, Germany. A young Russian chemist, Dmitri Mendeleev, attending this conference, was deeply influenced by a thesis presented by Stanislao Cannizaro, which described Cannizaro's method of determining atomic mass of elements. Mendeleev then started working on this aspect of atomic mass and periodicity. He later on stated the law of chemical periodicity. |
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| 8. |
What do you mean by Refining of Metals? |
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Answer» Refining of Metals Most metals obtained by the reduction process are not very pure. These have to be further refined or purified. Purification of the metal is the last step in metallurgy. Refining is based on the difference between the properties of metals and their impurities. |
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| 9. |
List out the hydrogen compounds known to you |
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Answer» 1. H2SO4 HCI HNO3 H2CO3 2. H2O H2O2 NaOH H2PO4 |
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| 10. |
MatchingA) Rotatory Motion1. RocketB) Oscillatory Motion2. A train entering into a railway stationC) Translatory Motion3. Movement of needle in a sewing machine.D) 100 years4. DecadeE) 10 years5. Movement of hands in a wrist watch.6. Century |
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| 11. |
………… foil used in inner packing of food materials and toffees. A) Sodium B) Magnesium C) Aluminium D) Silicon |
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Answer» C) Aluminium May be it will help u Correct option is C) Aluminium |
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| 12. |
Which one of the following doesn’t belong to the group? Carbohydrates, protein, polythene, Fats |
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Answer» Answer is Polythene |
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| 13. |
State three reasons for the following facts (i) Sulphur is a non-metal (ii) Magnesium is a metal One of the reasons must be supported with a chemical equation. |
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| 14. |
What are the two major constituents of the oceans? |
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Answer» Hydrogen and oxygen are the two major constituents of the oceans. |
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| 15. |
You came to know that the Diamond is a hardest material and it is a non-metal and similarly Mercury is a soft material and it is a metal.Write down the questions raised in your mind. |
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Answer» 1. Are all metals hard? 2. Are there any non-metals hard like diamond? 3. Are there any metals soft like mercury? 4. What makes mercury so soft and diamond so hard? 5. Can we distinguish those metals and non-metals depending on their opposite properties like these examples? |
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| 16. |
What do you know about hydrogen gas? |
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Answer» Hydrogen is the major component in the sun and stars. A very small quantity of hydrogen is seen in the atmosphere in free state. Water is a major compound of hydrogen. Hydrogen is present in large amounts in bio substances. |
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| 17. |
The components in food materials are given below. Filling the missing ones (a) Carbohydrate – Carbon, Hydrogen, ………(b) Protein – Carbon, Hydrogen, Oxygen, (c) Fats – Carbon, Hydrogen, |
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Answer» (a) Oxygen (b) Nitrogen (c) Nitrogen |
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| 18. |
SampleDoes bulb glow?A✓B✓CxDxA) A, B B) B, C C) C, D D) We cannot decide |
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Answer» Correct option is C) C, D |
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| 19. |
What do know about the presence of oxygen on earth |
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From the table you might have understood that the level of oxygen is very high in nature |
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| 20. |
Identify the relation in the first pair and fill up the missing ones in the second pair (a) PVC: Carbon, Hydrogen, Chlorine ………: Carbon, Hydrogen(b) Aqueous solution of CO2: H2CO3 Aqueous solution of SO2: (c) Na2CO3 .10.H2O : Washing soda NaHCO3 :……. |
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Answer» (a) Polythene (b) H2SO3 (c) Baking soda |
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| 21. |
Observe and analyse the graph showing the heat energy released during the combustion of various fuels.1. Which among the fuels given has the highest calorific value?2. What is calorific value?3. Which fuel has the highest calorific value?4. What will be the product formed when hydrogen burns in air? |
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Answer» 1. Hydrogen 2. The calorific value of a fuel is the heat energy released from one unit mass of that fuel on complete combustion. 3. Hydrogen 4. Water(H2O) |
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| 22. |
Try to find the metals and non-metals that you come across in the chapter on the periodic table. |
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| 23. |
Match the following:Group- AGroup- B1) Sulphur a) Foil decorated on sweets2) Silver b) Making of coins 3) Copper c) Making fireworksA) 1-b, 2-c, 3-a B) 1-a, 2-c, 3-b C) 1-c, 2-a, 3-b D) 1-c, 2-b, 3-a |
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Answer» C) 1-c, 2-a, 3-b |
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| 24. |
Which is more metallic, sodium or aluminium? |
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Answer» Sodium because it occupies higher position of the activity series. |
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| 25. |
Find out to which gases are the following statements related? (a) The gas which is combustible and is formed through the electrolysis of water (b) The gas that is used for water purification. (c) The element inevitable for the growth of plants. (d) The gas formed by the thermal decomposition of KMnO. |
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Answer» (a) Hydrogen (b) Chlorine (c) Nitrogen (d) Oxygen |
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| 26. |
Recall the names of the some of the laboratory acids and bases that you know. Write down their names in table and identify metal/non-metal present in them, which form oxides when react with oxygen. Take the help of your teacher. |
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| 27. |
Why don’t we use a metallic handle to an electric tester?A) Metals are good conductors of electricity B) Metals are highly expensive C) Metals are rarely occurs D) Metals are bad conductor of electricity |
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Answer» A) Metals are good conductors of electricity |
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| 28. |
What are the advantages of using hydrogen as a fuel? |
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| 29. |
Prepare and present a short note on the role of plants in maintaining the oxygen level. |
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Answer» In the presence of sunlight, the chlorophyll present in plants forms glucose by combining CO2 and water. As a result of this reaction (photosynthesis), oxygen is liberated. This helps to maintain the oxygen level in the atmosphere. 6CO2 + 6H2O → C6H12O6 + 6O2 |
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| 30. |
Certain gases are given in column A. Chemicals required to produce the gases are given in column B. Match them suitably. A B Hydrogen Calciumcarbonate + dil. HCl Oxygen Potassium permanganate Chlorine Magnessium + dil HCl Carbondioxide Potassium permanganate + Conc.HCl |
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| 31. |
Which of the following substance is used in preparation of oxygen in the laboratory? A) Potassium Permanganate B) Potassium Chloride C) Ammonium Chloride D) Copper Sulphate |
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Answer» Correct option is A) Potassium Permanganate |
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| 32. |
What are the limitations of using hydrogen as a fuel? |
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Answer» 1. Hydrogen is a gas that burns explosively in air 2. Distribution and storing the gas is not easy. |
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| 33. |
List out the chlorine compounds you are familiar with. |
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| 34. |
List out some compounds containing oxygen. |
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| 35. |
Why do the hot air balloons fly high? |
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| 36. |
What happens when acids are added to non-metals? |
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Answer» Non-metals do not react with acids. |
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| 37. |
What is a displacement reaction? |
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Answer» A more reactive metal displace a less reactive metal from its compound in aqueous solution is called displacement reaction |
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| 38. |
What is the reaction between hydrogen and oxygen? |
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Answer» Hydrogen burns in oxygen to form water. This is an exothermic reaction. (Water is also formed when electric sparks are passed through a mixture of hydrogen and oxygen) 2H2 + O2 → 2H2O + heat |
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| 39. |
Give examples for displacement reactions. |
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Answer» (1) Mg + 2HCl → MgCl2 + H2 (2) Zn + H2SO4 → ZnSO4 + H2 (3) Mg + 2HNO3 → Mg(NO3)3 + H2 (4) Zn + CuSO4 → ZnSO4 + Cu (5) 2NaBr + Cl2 → 2NaCl + Br2 (6) CH4 + Cl2 → CH3Cl + HCl |
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| 40. |
“We should give up chemical fertilizers completely and promote the use of organic fertilizers”. Do you agree with this statement? Substantiate your answer. |
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Answer» Yes 1. Organic fertilizers are echofriendly. 2. Preserve the inmate nature of the soil. 3. Does not create any health problem. |
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| 41. |
What is a combination reaction? |
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Answer» The reaction in which two or more simple substances (elements/compounds) combine to form a compound is called combination reaction. eg: 2H2 + O2 → 2H2O |
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| 42. |
Give examples for combination reactions. |
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Answer» (1) N2 + 3H2 → 2NH3 (2) 2Mg + O2 → 2MgO (3) H2 + S → H2S (4) 2Na + H2 → 2NaH (5) CaO + H2O→ Ca(OH)2 |
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| 43. |
Classify the given chemical reactions in the table below. (a) Mg + O2 → 2MgO (b) H2 + l2 → 2HI (c) 2H2O → 2H2 + O2 (d) NaCl + AgNO3 → AgCl + NaNO3 (e) ZnSO4 + BaCl2 → BaSO4 + ZnCl2(f) Zn + H2SO4 → ZnSO4 + H2 (g) FeSO4 + Zn → ZnSO4 + Fe |
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Answer» (a) Combination (b) Combination (c) Decomposition (d) Double decomposition (e) Double decomposition (f) Displacement (g) Displacement |
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| 44. |
Arrange the chemical reactions given below in the table under the heads combination reaction, decomposition, displacement reactions and double decomposition.(a) 2KCl → 2K + Cl2(b) CaCO3 → CaO + CO2(c) 2Hl → H2 + l2 (d) KCl + AgNO3 → AgCl + KNO3 (e) Mg + 2HCl → MgCl2 + H2 (f) 2H2 + O2 → 2H2O (g) Mg + H2SO4 → MgSO4 + H2(h) Na2SO4 + BaCl2 → BaSO4 + 2NaCl |
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Answer» (a) Decomposition (b) Decomposition (c) Combination (d) Double decomposition (e) Displacement (f) Combination (g) Displacement (h) Double decomposition |
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| 45. |
Which hormone promotes leaf fall? |
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Answer» Abscisic acid promotes leaf fall. |
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| 46. |
Name any two long day plants, two short day plants and two neutral day plants. |
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Answer» (i) Long day plants-Wheat, Cabbage. (ii) Short day plants-Rice, Potato. (iii) Day neutral plants-Balsam, Tomato. |
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| 47. |
Differentiate between short day plants and long day plants. |
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| 48. |
Select the correct acid, base or salt from the list in bracket for each of the statements given below:1. An acid obtained by dissolving sulphur trioxide in water is…. (sulphurous acid / sulphuric acid oleum)2. A volatile acid obtained when nitre reacts with non volatile concentrated sulphuric acid on heating is (hydrochloric acid / sulphuric acid/ nitric acid)3. A base obtained when lead nitrate undergoes thermal decomposition is……. (trilead tetroxide / lead (IV) oxide/ lead (II) oxide.4. An acid obtained when concentrated nitric acid is heated with sulphur is…….. (sulphurous acid / sulphuric acid / nitrous acid)5. The more volatile acid obtained when the less volatile acid reacts with sodium bicarbonate is……… (sulphuric acid / carbonic acid / nitric acid) |
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Answer» 1. Sulphuric acid 2. Nitric acid 3. Lead (II) oxide 4. Sulphuric acid 5. Carbonic acid |
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| 49. |
Select the correct acid, base or salt from the list in bracket for each of the statements given below:1. A salt prepared by neutralization in which titration is involved is…….. (MgCl2 / CaCl2 / NH4Cl / CuCl2 )2. An insoluble salt prepared by direct combination or synthesis is……. [FeCl3 / FeSO4 / FeS/Fe(NO3)2]3. A salt prepared by precipitation i.e. by double decomposition of two salt solutions is………… (Na2SO4 /PbSO4 / ZnSO4 / CuSO4)4. A salt prepared by simple displacement i.e. action of dilute acid on a metal is____ (PbCl2 / CuCL, AlCl3 / HgCl)5. Decomposition of calcium hydrogen carbonate with…. [dil. HNO3 /dil. HCl/dil. H2SO4] results in formation of calcium chloride.6. Action of dilute acid on a metallic sulphide results in evolution of____ [SO2 /H2S/CO2 ] gas.7. A salt which on hydrolysis produces a neutral solution is……. (sodium chloride / ammonium chloride / sodium carbonate) |
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Answer» 1. NH4Cl 2. FeS 3. PbSO4 4. AlCl3 5. dil.HCl 6. H2S 7. Sodium chloride |
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| 50. |
Select the correct acid, base or salt from the list in bracket for each of the statements given below:1. The insoluble base obtained when sodium hydroxide reacts with iron (III) chloride is…. (iron (II) hydroxide / iron (III) hydroxide / iron (II) oxide)2. A solution whose pH is above 7 is….. (vinegar / milk / liquor ammonia.3. The salt formed when sulphuric acid reacts with excess caustic soda solution is…… (sodium bisulphite / sodium sulphate / sodium sulphite / sodium bisulphate). 4. An example of an acid salt is……. [CH3COONa/NaNO3 / Na2HPO4 /NaKCO3 ]5. An example of a soluble salt is ……… (AgCl / PbSO4 /CaSO4 / CaCl2).6. An example of an insoluble salt is….. (Na2CO3 \ K2CCl,/ MgCO3 / (NH4)2 CO3) |
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Answer» 1. Iron (III) hydroxide 2. Liquor Ammonia 3. Sodium sulphate 4. Na2HPO4 5. CaCl2 6. MgCO3 |
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