Labels

UNIT – 3 : METALS AND NON-METALS(questions)

UNIT – 3 : METALS AND NON-METALS



Learning Points

  • Physical and chemical properties of metals and non-metals

  • Reactions of metals with air, water, acids, and other metal salt solutions

  • Reactivity series

  • Alloys, corrosion and prevention

  • Extraction of metals (roasting, calcination, reduction)

  • Formation of ionic bonds

I. Multiple Choice Questions (1 mark each)

  1. Which of the following pairs causes a displacement reaction?
    A. NaCl solution and copper metal B. MgCl₂ solution and aluminium metal C. FeSO₄ solution and silver metal D. AgNO₃ solution and copper metal

  2. Which method is suitable for preventing rusting of iron tava pan?
    A. Applying grease B. Painting C. Coating with zinc D. All of the above

  3. Food cans are coated with tin and not copper because
    A. Zinc is more expensive than tin B. Zinc’s melting point is higher C. Zinc is more reactive than tin D. Zinc is less reactive than tin

  4. The gas released when metals react with acids is
    A. H₂ B. CO₂ C. SO₂ D. NO₂

  5. A green layer forms when copper reacts with moist carbon dioxide because of
    A. Copper carbonate B. Copper chloride C. Copper nitrate D. Copper oxide

  6. Which of the following pairs causes a displacement reaction?
    A. NaCl + Cu B. MgCl₂ + Al C. FeSO₄ + Ag D. AgNO₃ + Cu

  7. Observe:
    CuSO₄ + Fe → FeSO₄ + Cu
    2AgNO₃ + Cu → Cu(NO₃)₂ + 2Ag
    Identify the correct statement:
    A. Iron is more reactive than copper and silver B. Iron less reactive than copper C. Copper is more reactive than silver but less than iron D. Silver is most reactive

  8. The electron configurations of elements X and Y are 2,8,8,1 and 2,8,7. The bond formed is
    A. Covalent B. Metallic C. Hydrogen D. Ionic

  9. Correct increasing order of reactivity for Al, Na, K, Ca, Mg is
    A. Al < Mg < Ca < Na < K B. K < Mg < Ca < Na < Al C. K < Na < Ca < Mg < Al D. Al < Na < Mg < Ca < K

  10. A process used to convert metal sulphide ores into their oxides is
    A. Calcination B. Roasting C. Reduction D. Electrolysis

  11. Which metal displaces copper from copper sulphate?
    A. Mercury B. Gold C. Iron D. Silver

  12. Fe + CuSO₄ → FeSO₄ + Cu
    Zn + FeSO₄ → ZnSO₄ + Fe
    Order of decreasing reactivity:
    A. Zn > Fe > Cu B. Fe > Cu > Zn C. Zn > Cu > Fe D. Cu > Fe > Zn

  13. Zn + FeSO₄ → ZnSO₄ + Fe
    2Al + 3ZnSO₄ → Al₂(SO₄)₃ + 3Zn
    Order of increasing reactivity:
    A. Fe < Zn < Al B. Al < Zn < Fe C. Zn < Fe < Al D. Al < Fe < Zn

  14. Al, Fe, Mg and Zn reacted with HCl. The decreasing reactivity order is
    A. Mg > Al > Zn > Fe B. Al > Mg > Fe > Zn C. Fe > Zn > Al > Mg D. Fe > Mg > Zn > Al

  15. Which reaction is possible?
    A. FeSO₄ + Pb → PbSO₄ + Fe B. ZnSO₄ + Fe → FeSO₄ + Zn
    C. 2AgNO₃ + Cu → Cu(NO₃)₂ + 2Ag D. PbCl₂ + Cu → CuCl₂ + Pb

  16. Elements A(2,8,2), B(2,8), and C(2,8,7) form ionic compounds between
    A. A and B B. B and C C. A and C D. A and B

II. One Mark Questions

  1. What are amphoteric oxides?

  2. Name two metals that react with concentrated nitric acid.

  3. Name good and poor conductors of heat.

  4. Name the non-metal that conducts electricity.

  5. What is ductility?

  6. What are ionic compounds?

  7. How can an iron ring be copper-plated without electricity?

  8. What is the thermite reaction?

  9. Which metals do not corrode easily?

  10. What is an alloy?

  11. Name metals found in free state.

  12. Which chemical method is used to obtain metals from oxides?

  13. Why do ionic compounds have high melting points?

  14. What is roasting in metallurgy?

III. Two-Mark Questions

  1. Which gas is released when HCl reacts with reactive metals? Write equation for Fe + H₂SO₄.

  2. Write balanced equations for Al₂O₃ reacting with acid and base.

  3. Mention four properties of ionic compounds.

  4. Why does calcium not burn in water though it releases hydrogen? Write equation.

  5. Name two metals reacting quickly with cold water. Write products.

  6. Physical properties used in:
    i) Gold jewellery ii) Nickel in guitar strings

  7. List four physical properties of metals.

  8. List four physical properties of non-metals.

  9. Match metals to properties:
     i) Liquid at room temp ii) Cut with knife iii) Good conductor iv) Poor conductor

  10. Write equations for: (a) Iron with steam (b) Calcium with water

  11. Why can carbon not reduce oxides of Na, Mg, Al?

  12. Name two metals that displace hydrogen from acid and two that do not.

  13. In electrolytic purification of metal M, identify anode, cathode and electrolyte.

  14. Steps to prevent rusting of iron.

  15. Na and Ca in separate beakers with water — explain observations.

  16. i) Why no hydrogen from metals with conc. HNO₃? ii) Reaction of Al with HCl.

  17. What is galvanisation? How does it prevent rust?

  18. Which metal reduces Fe₂O₃ in thermite reaction? Write equation.

  19. What are alloys? Name elements in bronze and solder.

  20. What are ores? Explain conversion of sulphide ores to oxides.

  21. Difference between smelting and roasting.

  22. State the method to reduce cinnabar.

  23. Four metals (Zn, Fe, Mg, Cu) in test tubes with FeSO₄ — which react and why?

  24. Observe three iron nails in test tubes (rusting activity):
     i) Which rusts? ii) Why others do not?

IV. Three-Mark Questions

  1. Give reasons:
     i) Ionic compounds insulate in solid but conduct in molten form.
     ii) Na/K stored in kerosene.
     iii) Aluminium used for utensils despite being reactive.

  2. A student burns sulphur:
     a) Effect on dry and wet litmus papers
     b) Balanced equation

  3. Draw diagram showing reaction of steam on metal — label outlet and hydrogen.

  4. Draw electrolysis of copper diagram — label cathode and mud.

  5. How are mid-reactivity metals treated before alloying?

  6. a) Why do silver/copper lose lustre?
     b) How galvanising protects iron?
     c) Why is Al₂O₃ a double oxide?

V. Four-Mark Questions

  1. (a) Show electron transfer in Na₂O and MgO formation
     (b) Name ions in these compounds

  2. Four metals (A, B, C, D) tested with FeSO₄, CuSO₄, ZnSO₄, AgNO₃ — identify
     a) Most reactive metal
     b) Observation when B in CuSO₄
     c) Arrange metals by reactivity

  3. (a) Draw electron dot structures of Na, O, Mg
     (b) Explain: i) Minerals ii) Iron iii) Mud

  4. Predict displacement among Zn, Mg, Cu oxides and these metals.

  5. Give reasons:
     a) Iron alloys are more useful than pure iron
     b) Copper loses colour on exposure to air
     c) Aluminium oxide is amphoteric
     d) Hydrogen not released with conc. HNO₃

  6. Show formation of MgCl₂ using electron dots.

VI. Five-Mark Questions

  1. Differentiate annealing and roasting.
    Explain extraction of zinc with equations and reason for reduction step.

  2. (a) Explain ionic bond formation between Na and Cl (Na = 11, Cl = 17).
    (b) List four properties of ionic compounds.




🧲 UNIT – 3 : METALS AND NON-METALS – KEY ANSWERS

I. Multiple Choice Answers (1 mark each)

Q.No Answer Explanation
1 ✅ (D) AgNO₃ + Cu → Cu(NO₃)₂ + 2Ag Copper displaces silver – displacement reaction
2 ✅ (D) All of the above Grease, paint or zinc coating prevent rust
3 ✅ (C) Zinc is more reactive than tin Tin protects food, zinc would react
4 ✅ (A) Hydrogen (H₂) Metal + acid → Salt + H₂
5 ✅ (A) Copper carbonate Green layer = basic copper carbonate
6 ✅ (D) AgNO₃ + Cu Copper displaces silver
7 ✅ (C) Copper more reactive than silver but less than iron Based on reactivity series
8 ✅ (D) Ionic bond Metal donates electrons to non-metal
9 ✅ (A) Al < Mg < Ca < Na < K True reactivity order
10 ✅ (B) Roasting Metal sulphide → Metal oxide
11 ✅ (C) Iron Fe displaces Cu from CuSO₄
12 ✅ (A) Zn > Fe > Cu Reactivity decreases downward
13 ✅ (A) Fe < Zn < Al Increasing reactivity
14 ✅ (A) Mg > Al > Zn > Fe Decreasing order of reactivity
15 ✅ (C) 2AgNO₃ + Cu → Cu(NO₃)₂ + 2Ag Feasible reaction
16 ✅ (C) A and C Ionic bond between metal & non-metal

II. 1-Mark Answers

  1. Amphoteric oxides:
    React with both acids and bases to form salt and water.
    Eg: Al₂O₃, ZnO.

  2. Metals reacting with conc. HNO₃:
    Mg and Mn (form nitrates, not H₂ gas).

  3. Good/Poor conductors:
    Good – Silver, copper. Poor – Lead, mercury.

  4. Non-metal conducting electricity:
    Graphite.

  5. Ductility:
    Property of metals that allows them to be drawn into thin wires.

  6. Ionic compounds:
    Compounds formed by transfer of electrons from metals to non-metals (e.g. NaCl).

  7. Copper plating without electricity:
    By immersing iron in CuSO₄ solution → Fe displaces Cu.

  8. Thermite reaction:
    Fe₂O₃ + 2Al → 2Fe + Al₂O₃ + heat.

  9. Metals that don’t corrode easily:
    Gold and platinum.

  10. Alloy:
    Homogeneous mixture of two or more metals (e.g. brass, bronze).

  11. Metals in free state:
    Gold and platinum.

  12. Chemical method to obtain metals from oxides:
    Reduction with carbon, CO, or Al.

  13. Ionic compounds have high melting points:
    Strong electrostatic forces between ions.

  14. Roasting:
    Heating sulphide ores in presence of air to form oxides.

III. Two-Mark Answers

  1. Gas evolved:
    Hydrogen gas.
    Equation: Fe + H₂SO₄ → FeSO₄ + H₂↑

  2. Al₂O₃ reaction equations:
    Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂O
    Al₂O₃ + 2NaOH → 2NaAlO₂ + H₂O

  3. Properties of ionic compounds:

  • High melting/boiling points

  • Conduct in molten/solution state

  • Hard and brittle

  • Form crystals

  1. Calcium reaction:
    Ca + 2H₂O → Ca(OH)₂ + H₂↑ (no fire, mild reaction).

  2. Metals reacting with cold water:
    Na and K; form alkali and hydrogen.

  3. Physical properties:
    i) Gold – malleable and lustrous.
    ii) Nickel – tensile and sonorous.

  4. Properties of metals:

  • Lustrous, malleable, ductile, good conductors.

  1. Properties of non-metals:

  • Non-lustrous, brittle, poor conductors, low density.

  1. Matching:
    i) Mercury ii) Sodium iii) Copper iv) Lead

  2. Equations:
    (a) 3Fe + 4H₂O → Fe₃O₄ + 4H₂↑
    (b) Ca + 2H₂O → Ca(OH)₂ + H₂↑

  3. Reason:
    Na, Mg, Al form very stable oxides — carbon can’t reduce them.

  4. Metals displacing H₂: Zn, Fe
    Do not displace: Cu, Ag

  5. Electrolytic purification:
    Anode – impure metal; Cathode – pure metal; Electrolyte – salt of same metal.

  6. Prevent rusting:
    Painting, oiling, galvanising, alloying.

  7. Na + H₂O: violent with flames
    Ca + H₂O: gentle, effervescence of H₂

  8. (i) Conc. HNO₃ oxidises H₂ to H₂O.
    (ii) 2Al + 6HCl → 2AlCl₃ + 3H₂↑

  9. Galvanisation:
    Coating iron with zinc to prevent rusting; zinc forms protective oxide layer.

  10. Thermite reducing agent:
    Aluminium; Fe₂O₃ + 2Al → 2Fe + Al₂O₃ + heat.

  11. Alloys:
    Mixture of metals to improve strength/corrosion resistance.

  • Bronze – Cu + Sn

  • Solder – Pb + Sn

  1. Ores:
    Naturally occurring metal compounds.
    Sulphide ores → heated in air → oxides (roasting).

  2. Smelting vs Roasting:

  • Smelting: Extraction by melting ore

  • Roasting: Heating in air to form oxides

  1. Cinnabar (HgS):
    Heated in air → HgO → reduced to Hg on further heating.

  2. Zn, Mg react; Fe, Cu don’t:
    Because Zn and Mg are more reactive than Fe.

  3. Rusting test:
    Only nail exposed to air + moisture rusts; others lack one condition.

IV. Three-Mark Answers

  1. (i) Ionic compounds conduct only in molten/solution state (ions free).
    (ii) Na/K stored in kerosene to avoid air/moisture reaction.
    (iii) Al forms oxide layer → prevents further corrosion.

  2. Sulphur combustion:
    S + O₂ → SO₂
    Dry litmus – no change; Wet blue litmus – turns red.

  3. Diagram:
    Reaction of steam with iron — shows delivery tube, outlet, and hydrogen gas collection.

  4. Electrolysis of copper:
    Anode – impure Cu; Cathode – pure Cu; Electrolyte – CuSO₄ solution;
    Anode dissolves, pure Cu deposits on cathode; impurities fall as anode mud.

  5. Middle reactivity metals (Zn, Fe, Pb):
    Roasted → oxides → reduced by C/CO.

  6. (a) Cu/Ag lose lustre forming oxides.
    (b) Galvanised Zn layer prevents air contact.
    (c) Al₂O₃ reacts with both acid & base → amphoteric.

V. Four-Mark Answers

  1. Electron transfer:
    Na (2,8,1) → Na⁺ O (2,6) → O²⁻ → Na₂O
    Mg (2,8,2) → Mg²⁺ O (2,6) → O²⁻ → MgO
    Ions: Na⁺, Mg²⁺, O²⁻

  2. Metal reactivity series test:
    (a) Most reactive – metal that displaces all others.
    (b) When B in CuSO₄ – red Cu deposited.
    (c) Order – D < C < B < A (example as per experiment).

  3. (a) Electron dot structures – Na•, :O:, Mg•
    (b) (i) Minerals – natural metal compounds.
    (ii) Iron – obtained from haematite.
    (iii) Mud – impurities after electrolysis.

  4. Displacement prediction:
    Mg reduces ZnO, Fe₂O₃, CuO; Zn reduces Fe₂O₃, CuO; Fe reduces CuO only.

  5. Reasons:
    (a) Alloys stronger, rust-resistant.
    (b) Cu reacts with moist CO₂ → green CuCO₃.
    (c) Al₂O₃ reacts with both acid and base.
    (d) Conc. HNO₃ oxidises H₂ → no gas.

  6. Formation of MgCl₂:
    Mg → Mg²⁺ + 2e⁻
    Cl₂ + 2e⁻ → 2Cl⁻
    → Mg²⁺ + 2Cl⁻ → MgCl₂

VI. Five-Mark Answers

  1. Annealing vs Roasting:

  • Roasting: Heating sulphide ores in air → oxides.

  • Annealing: Softening metals by heating then cooling slowly.
    Extraction of Zinc:
    ZnS → ZnO (roasting) → Zn (reduction with C).

  1. (a) Ionic bond (NaCl):
    Na → Na⁺ + e⁻
    Cl + e⁻ → Cl⁻
    → Na⁺Cl⁻ (electrostatic attraction).
    (b) Properties:

  • High melting point

  • Soluble in water

  • Conducts in molten state

  • Brittle solids

✅ Summary:
These are officially aligned KSEAB 2024–25 answers from 10th LBA Science (EM) — same 

Labels:

Comments

Post a Comment

Popular Posts