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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Why are metals good conductors of electricity while non-metals are not ? |
| Answer» In metal atoms, the valence electrons are loosly held by the nucleus and are mobile. Therefore, metals are good conductors of electricity. In atoms of non-metals, the valence electrons are held more firmly by the nucleus and are not mobile. Therefore, non-metals are poor conductors. | |
| 2. |
A metal M found in nature as sulphide ore `(M_(2)S)` is one of the good conductors of heat and electricity and is used in making electric wires : (i) Identify the metal M (ii) Write the balanced chemical equations involved in the process of extraction of the metal. (iii) Draw a labelled diagram for the electrolytic refining of the metal. |
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Answer» (i) The available clue suggests that the metal M is copper (Cu) and the sulphide ore is cuprous sulphide `(Cu_(2)S)` also known as copper glance. (ii) For the balanced chemical equation. (iii) For the labelled diagram of electrolytic refining. |
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| 3. |
Generally, non-metals are not conductors of electricity. Which of the following is a good conductor of electricity?A. DiamondB. GraphiteC. PhosphorusD. Iodine. |
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Answer» Correct Answer - B Graphite is a good conductor of eleectricity. |
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| 4. |
Give two examples each of the metals that are good conductors and comparatively poor conductors of heat respectively. |
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Answer» Good conductors Silver and copper. Poor conductors Lead and mercury. |
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| 5. |
Calamine ore can be conerted into zinc oxide by the process of:A. dehydrationB. roastingC. calcinationD. sulphonation |
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Answer» Correct Answer - C Correct Answer - c |
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| 6. |
In the formation of the compound AB, atoms of A lost one electron each while stoms of B gained one electron each. What is the nature of bond in AB? Predict the two properties of AB. |
| Answer» Here, the atoms of A lose electrons whereas the atoms of B gain electrons. This means that there is a transfer of electrons from atoms of A to atoms of B. now, the bond formed by the transfer of electrons is called ionic bond. So, the nature of bond in the compound AB is ionic. the two properties of the ionic compound AB will be :(i) it will be soluble in water, and (ii) it will conduct electricity when dissolved in water or melted.. | |
| 7. |
Which one of the following properties is not generally exhibited by ionic compounds?A. solubility in waterB. electrical conductivity in solid state.C. High melting and boiling pointsD. electrical conductivity in molten state |
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Answer» Correct Answer - B Correct Answer - b |
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| 8. |
(i) Carbonate and sulphide ores are usually converted into oxides during the process of extraction of metals. (ii) Ionic compounds have generally high melting points. (iii) Hydrogen is not a metal but is has been assigned a place in the reactivity series of metals. (iv) The galvanised iron article is protected against rusting even if the zinc layer is broken. |
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Answer» (i) It is easy to reduce metal oxide to the metallic form than metal carbonate or metal sulphide. (ii) In ionic compounds, oppositely charged ions are closely packed and the attractive forces are very strong. Therefore, ionic compounds have high melting points. (iii) Hydrogen has been assigned a place in the reactivity series of metals because just like metals, it behaves as an electropositive element. |
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| 9. |
Which one of the following properties is not generally exhibited by ionic compounds?A. Solubility in waterB. Electrical conductivity in solid stateC. High melting and boiling pointsD. Electrical conductivity in molten state. |
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Answer» Correct Answer - B Ionic compounds are conducting due to the movement of ions. Since the ions donot move in the solid state, these compounds are therefore, not conducting in the solid state. |
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| 10. |
Zinc blende ore can be converted into zinc oxide by the process of:A. roastingB. hydrogenationC. chlorinationD. calcination |
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Answer» Correct Answer - A Correct Answer - a |
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| 11. |
State the property utilized in the following : (i) Graphite in making electrodes. (ii) Electic wires are coated with polyvinyl chloride (PVC) or a rubber like material. (iii) Metal alloys are used for making bells and strings of musical instruments. |
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Answer» (i) Graphite is a good conductor of electricity inspite of the reason that it is a non-metal. It is a crystalline allotropic form of carbon and its electrical conductivity is because of the presence of a free electron in each atom which is available to conduct electricity. (Carbon and its Compounds) (ii) Electric wires are generally made of metals like copper and aluminium which are good conductors of electricity. In order to insulate, these are kept covered with PVC or any other rubber like material. (iii) Gun metal (alloy of Cu = 90 & Sn = 10 parts) is used for making bells because it is very heavy. Similarly, stainless steel or any other variety of steel is used for the manufacture of strings of musical instruments since it is ductile in nature. Assign suitable reasons for the following : |
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| 12. |
Reactions involved in the smelting of iron in the blast furnace are given below. Arrange them in the correct sequence. (1) `CaCO_3to CaO+CO_2+43kcal` (2) `CaO+SiO_2toCasiO_3` (3) ` C+O_2toCO_2+97kcal` (4) `CO_2+CtoCO-39kcal` (5) `FeO //Fe_2O_3+COtoFe+CO_2`A. 34125B. 31452C. 54321D. 23541 |
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Answer» Correct Answer - A (i) `C+O_2+97kcal` (ii) `CO_2+Cto2CO-39 kcal` (iii) `CaCO_3to CaO+CO_2+43 kcal` (iv) `CaO+SiO_2 to CaSiO_3` (v) `FeO//Fe_2O_3+COtoFe+CO_2` |
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| 13. |
Which of the following reactions takes place in the lower region of a blast furnace ?A. `CO_2+Cto2CO-39 kcal`B. `C+O_2to CO_2+97kcal`C. `FeO+COtounderset (750-600^@C)to Fe+CO_2`D. `CaO+SiO_3` |
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Answer» Correct Answer - A Combination of carbon takes place in lower region of blast furnace. `C+O_2toCo_2+97kcal` |
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| 14. |
Rock salt is an ore of one of the following metals. This metal is:A. MnB. NaC. FeD. Cu |
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Answer» Correct Answer - B Correct Answer - b |
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| 15. |
You are provided with three metals : Sodium, magnesium and copper. Using only water as the reactant, how will you identify them ? |
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Answer» • The metal which reacts violently with cold water and catches fire is sodium. • The metal which evolves hydrogen gas upon heating with water is magnesium. • The metal which dose not react with water even on strong heating is copper. |
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| 16. |
Which one of the following properties is not generally exhibited by ionic compounds?A. Solubility in waterB. Electrical conductivity in solid stateC. High melting and boiling pointsD. Electrical conductivity in moiten state |
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Answer» Correct Answer - b Ionic compounds can conduct electricity in molten or aqueous state only. in soiid state, these are non-conductor of electricity because of the absence oi iree ions. in the solid ionic compounds. the ions are held together in fixed position by strong electrostatic force and cannot move freely. So, eiectricai conductivity in solid state is not generally exhibited by ionic compounds |
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| 17. |
An element A which is a part of common salt and kept under kerosene reacts with another element B of atomic number 17to give a prodce C. When an aqueous solution of product C is electrolysed then a compound D is formed and two gases are liberated. (a) What are A and B? (b) Identify C and D. (c) What will be the action of C on litmus solution? Why? (d) State whether element B is a solid. liquid or gas room temperature. (e) Write formula of the compound formed when element B reacts with an element E having atomic number 5. |
| Answer» (a) A is sodium and B is chlorine (b) C is sodium chloride and D is sodium hydroxide (c) It will turn litmus solution blue, Because it is a base (d) gas (e) `EB_(3)` | |
| 18. |
Which of the following cannot be concentrated by froth flotation process ?A. zinc blendeB. copper pyritesC. iron pyritesD. limonite |
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Answer» Correct Answer - A Limonite, `Fe_2O_3.H_2O` cannot be concentrated by froth flotation process. |
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| 19. |
Why is the iron obtained from the blast furnace not used for any article ? |
| Answer» At high tempeature ,carbon monoxide disproportionates rapidly into carbon dioxide and carbon and the change is catalysed by iron and its oxides. Due to this, the ore gets impregnated with carbon. The high amount of carbon makes iron derived from the blast furnace brittle, hard and unsuitable for making any article. | |
| 20. |
The wires carrying current in homes have a coating of PVC. Why ? |
| Answer» Electric current is carried generally by copper wires. In order to insulate these, they are given a coating of PVC which acts as an insulator. | |
| 21. |
From amongst the metals sodium, calcium, aluminium, copper and magnesium, name the metal (i). Which reacts with water only on boiling, and (ii). Another which does not react even with steam. |
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Answer» (i). Aluminium (ii). Copper |
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| 22. |
Which of the following metals can be obtained from haematite ore?A. CopperB. sodiumC. zincD. iron |
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Answer» Correct Answer - D Correct Answer - d |
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| 23. |
From amongst the following, choose the metals and non-metals and state one of the properties on the basis of which you have made you choice. (i). Graphite (ii). Sodium (iii). Phosphorus (iv). Helium. |
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Answer» Out of graphite, sodium, phosphorus and helium, only sodium is a metal. Allother are non-metals. This choice has been made on the basis of the nature of their oxides. This is because metals form basis oxides whereas non-metals form acidic oxides or neutral oxides. (i) Graphite is actually carbon element. graphite or carbon usually forms an acidic oxide, carbon dioxide, so, graphite is a non-metal. (ii). Sodium forms a basic oxide, sodium oxide. So, sodium is a metal (iiii). Phosphorus forms an acidic oxide, phosphorus pentoxide,. So, phosphorus is a non-metal (iv). Helium is a gas, so it is a non-metal, being an inert gas, helium does not form an oxide. |
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| 24. |
Electrical wires have a coating of an insulating material. The material, generally used isA. SulphurB. graphiteC. PVCD. All can be used |
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Answer» Correct Answer - c PVC is an insulating substance. It does not allow electric current to pass through it. The electrical wires have a covering of PVC around them. |
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| 25. |
An element A is soft and can be cut with a knife. This is very reactive to air and cannot be kept open in air. It reacts vigorously with water. Identify the element from the following. A. MgB. NaC. PD. Ca |
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Answer» Correct Answer - b From the properties of the element described In the question, it can be said surely that the element IS sodium (Na). |
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| 26. |
If A,B,C,D,E,F,G,H,I,J and K represetnt metals in the decreasing order of their reactivity, which one of them is most likely to occur in a free state in nature? |
| Answer» Correct Answer - K | |
| 27. |
(a) What is the activity series of metals ? Arrange the metals Zn, Mg, Al, Cu and Fe in a decreasing order of reactivity. (b) What would you observe when you put (i) some zinc pieces into blue copper sulphate solution ? (ii) some copper pieces into green ferrous sulphate solution ? (c ) Name a metal which combines with hydrogen gas. Name the compound formed. |
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Answer» (a) (i) Blue colour of copper sulphate solution would slowly disappear. (ii) No change would be noticed. (c ) Sodium combines with hydrogen to form sodium hydride. `2Na + H_(2)rarr underset("Sod. hydride")(2NaH)` |
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| 28. |
Write one example each of the following metals : (a) Most malleable and most ductile. (b) Best conductor of heat and the poorest conductor of heat (c ) A metal with highest melting point and a metal with lowest melting point. |
| Answer» (a) Gold (b) Silver, lead (c ) Tungsten, Mercury. | |
| 29. |
"Is malleable and ductile " best describes:A. a metalB. A compoundC. A non-metalD. a solution |
| Answer» Correct Answer - A | |
| 30. |
The electronic configuration of three elements X, Y and Z are: `X:2` `Y:2,8,7` `Z:2,8,2` Which of the following is correct regarding these elements?A. X is a metalB. Y is a metalC. Z is a non-metalD. Y is a non-metal and Z is a metal |
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Answer» Correct Answer - D Correct Answer - d |
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| 31. |
Give the electronic configuration of an element having atomic number 11. |
| Answer» The element with atomic number (Z) 11 is sodium (Na). Its electronic configuration is 2, 8, 1. | |
| 32. |
The electronic configurations of two elements A and B are given below: A 2,6 B 2,8,1 (a). What type of chemical bond is formed between the two atoms of A? (b). What type of chemcial bond will be formed between the atoms of A and B? |
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Answer» (a) Covalent bond (b) Ionic bond |
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| 33. |
the electronic configurations of four particles A,B,C and D are given below: A 2,8,8 B 2,8,2 C 2,6 D 2,8 Which electronic configurations represents: (i) magnesium atom? (ii) oxygen atom? (iii) sodium ion? (iv). chloride ion? |
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Answer» (i) B (ii) C (iii) D ltBrgt (iv) A |
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| 34. |
The atomic number of an element X is 12. (a). What must an atom of X do to attain the nearest inert gas electron configurations? (b) Which inert gas is nearest to X? |
| Answer» (a) Lose 2 electrons (b) Neon | |
| 35. |
The solution of one of the following compounds will not conduct electricity. This compound is:A. NaClB. `C Cl_(4)`C. `MgCl_(2)`D. `CaCl_(2)`. |
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Answer» Correct Answer - B Correct Answer - b |
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| 36. |
What type of chemical bonds are present in a solid compound which has a high melting point, does not conduct electricity in the solid state but becomes a good conductor in the molten state?. |
| Answer» Correct Answer - Ionic bonds | |
| 37. |
Which of the following pairs will give displacement reactions? (a). NaCl solution and copper metal (b). `MgCl_(2)` solution and aluminium metal. (c). `FeSO_(4)` solution and silver metal. (d). `AgNO_(3)` solution and copper metal. |
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Answer» (a). Copper metal is less reactive than sodium metal (Na), so no displacement reaction will occur between NaCl solution and copper metal. (b). Aluminimum metal is less reactive than magnesium metal (Mg). So no displacement reaction will take place between `MgCl_(2)` solution and aluminium metal. (c). silver metal is less reactive than iron metal (Fe), so no displacement reaction will occur between `FeSO_(4)` solution and silver metal. (d) Copper metal is more reactive than silver metal (Ag), soa displacement reaction will take place between `AgNO_(3)` solution and copper metal. |
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| 38. |
An element A is soft and can be cut with a knife. This is very reactive to air and cannot be kept open in air. It reacts vigorously with water. Identify the element from the following. A. MgB. NaC. SD. Mg |
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Answer» Correct Answer - B Sodium (Na) gives all the characteristics of the element X. |
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| 39. |
Which metal foil is used for packing some of the medicine tables.? |
| Answer» Aluminium foil | |
| 40. |
Name the non-metal which is used: (a). To convert vegetable oil into vegetable ghee (solid fat) (b). As a rocket fuel (in liquid form). (c). To make electrodes of dry cells (d). To preserve food materials. (e). In the vulcanisation of rubber. |
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Answer» (a). Hydrogen (b). Hydrogen (c). Carbon (as Graphite) (d). Nitrogen (e) Sulphur |
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| 41. |
What is meant by "brittleness"? Which type of elements usually show brittleness: metals or non-metals? |
| Answer» Correct Answer - Non-metals | |
| 42. |
Which one of the following Figures correctly describes the process of electrolytic refining? A. B. C. D. |
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Answer» Correct Answer - c For the process of electrolytic refining, impure metal is made anode and is connected to the positive terminal of battery. Pure metal is made cathode and is connected to the negative terminal of the battery. `Cu^(2+)` ions from the soiution are deposited on the cathode while Cu from impure anode dissolves into the soiution and the impurities settle down below anode as anode mud. |
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| 43. |
During electrolytic refining of zinc, it getsA. deposited on cathodeB. deposited on anodeC. deposited on cathode as well as anodeD. remains in the solution |
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Answer» Correct Answer - a During electrolytic refining of zinc (Zn), the pure zinc metal is deposited on cathode. It is connected to the negative terminal of the battery. `Zn^(2+)` ions from the solution move towards the negatively charged cathode. Hence Zn is deposited on the cathode. |
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| 44. |
Which of the following can undergo a chemical reaction ?A. `MgSO_(4) + Zn`B. `ZnSO_(4) + Fe`C. `CaSO_(4) + Pb`D. `CuSO_(4) + Al` |
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Answer» Correct Answer - D Only Al can displace Cu from `CuSO_(4)` solution since it is placed above Cu in the activity series. All these reactions are not feasible. |
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| 45. |
Which of the following pairs will give displacement reactions?A. NaCl solution and copper metalB. `MgCl_(2)` solution and aluminium metalC. `FeSO_(4)` solution and silver metalD. `AgNO_(3)` solution and copper metal. |
| Answer» (d) `AgNO_(3)` solution and copper metal | |
| 46. |
Alloys are homogeneous mixtures of a metal with a metal or non-metal. Which among the following alloys contain non-metal as one of its constituents? A. BrassB. BronzeC. AmalgamD. Steel. |
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Answer» Correct Answer - d Steel is an alloy which contains iron (a metal) and carbon (a non-metal). If we consider other options, then-Brass is an alloy of two metals copper and zinc. Bronze is an alloy of copper and tin. Amalgam is also formed by mixing mercury with other metal. |
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| 47. |
A non-metal A is an important constituent of our food and forms two oxides B and C. Oxide B is toxic whereas C causes global warming. (a) Identify A, B and C. (b) To which group of periodic table does A belong? |
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Answer» The non-metal A is carbon. It is an important constituents of our food in different forms. For example, glucose `(C_(6)H_(12)O_(6))` contains carbon. In fact, all food materials are organic compounds and these contain carbon as essential constituent. The two oxides of carbon are, carbon monoxide (B) and carbon dioxide (C ). Carbon dioxide causes global warming. (a) A = Carbon (C ) , B = Carbon monoxide (CO) , C = Carbon dioxide `(CO_(2))` (b) Carbon is the first member of group 14 in the Long form of Periodic Table. |
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| 48. |
(a) Define corrosion, what is the nature given to corrosion of iron ? (b) Name the colour of coating formed on silver and copper when exposed to air. (c ) List two damages caused by corrosion and suggest, how these can be prevented. |
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Answer» (a) For definition of corrosion. Corrosion of iron is known as rusting. (b) Coating deposited on the surface of silver metal is of silver sulphide `(Ag_(2)S)`. It is black in colour. The coating deposited on copper surface is of basic copper carbonate `Cu(OH)_(2)CuCO_(3)`. It is green in colour. |
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| 49. |
Which one of the following four metals would be displaced from the solution of its salts by other three metals? A. MgB. CuC. ZnD. Fe. |
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Answer» Correct Answer - B Cu is the least reactive and would be displaced from its salts by other metals. |
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| 50. |
An alloy isA. An elementB. a compoundC. a homogeneous mixtureD. a heterogeneous mixture |
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Answer» Correct Answer - C An alloy is a homogeneous mixture of two or more elements (metals or non-metals). |
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