Vidaara.orgClass 10 · Chemistry
CodeC10-CHEM-3-CW
Metals and Non-metals — Chapter Worksheet
Name: ____________________
Roll No.: __________
Date: ____________
General Instructions
- This is a full-length worksheet covering the whole chapter — every topic is included.
- All questions are compulsory.
- Section A carries 1 mark each, Section B 2 marks, Section C 3 marks and Section D 5 marks.
- Write balanced chemical equations and show all working for Sections B, C and D.
Section A — Multiple Choice Questions
6 × 1 = 6 marks
1.
Which property is shown only by metals?
- A.brittleness
- B.sonority
- C.dullness
- D.low density
2.
The oxide CO2 is:
- A.basic
- B.acidic
- C.amphoteric
- D.neutral
3.
Which metal does NOT react with dilute HCl?
- A.Mg
- B.Zn
- C.Cu
- D.Fe
4.
The bond in MgO is:
- A.covalent
- B.ionic
- C.metallic
- D.hydrogen
5.
Calcination is suited to which ore?
- A.sulphide
- B.carbonate
- C.oxide
- D.native metal
6.
Bronze is an alloy of copper and:
- A.zinc
- B.tin
- C.nickel
- D.lead
Section B — Short Answer (2 marks)
3 × 2 = 6 marks
7.
Give one reason each: (i) sodium is stored in kerosene, (ii) gold is found in the free state.
8.
Write balanced equations for the reaction of (i) zinc with dilute H2SO4 and (ii) iron with steam.
9.
Why do ionic compounds have high melting points but are brittle?
Section C — Short Answer (3 marks)
3 × 3 = 9 marks
10.
Explain the formation of magnesium chloride (MgCl2) by transfer of electrons.
11.
Differentiate between roasting and calcination, with one equation each.
12.
List three methods of preventing corrosion of iron and explain how galvanisation works.
Section D — Long Answer (5 marks)
2 × 5 = 10 marks
13.
Using the reactivity series, explain how the method of extraction of a metal depends on its position in the series, with one example of each type.
14.
Compare metals and non-metals on the basis of (i) physical properties, (ii) reaction with oxygen, and (iii) behaviour towards acids, giving examples and noting two exceptions.
Answer Key
Section A — Multiple Choice Questions
- (B) sonority
- (B) acidic
- (C) Cu
- (B) ionic
- (B) carbonate
- (B) tin
Section B — Short Answer (2 marks)
- (i) Sodium is very reactive and would react with air and moisture, so kerosene keeps them away. (ii) Gold is least reactive (bottom of the series), so it does not combine with other elements and occurs native.
- (i) Zn + H₂SO₄ → ZnSO₄ + H₂. (ii) 3Fe + 4H₂O (steam) → Fe₃O₄ + 4H₂.
- Strong electrostatic forces in the lattice need much heat to break (high melting point); when struck, like charges come opposite and repel, so the crystal shatters (brittle).
Section C — Short Answer (3 marks)
- Mg (2,8,2) loses 2 electrons to form Mg²⁺ (2,8). Two chlorine atoms (2,8,7) each gain one electron to form two Cl⁻ (2,8,8). The ions attract to give the ionic compound MgCl₂: Mg + Cl₂ → MgCl₂.
- Roasting: sulphide ore heated strongly in air to the oxide, e.g. 2ZnS + 3O₂ → 2ZnO + 2SO₂. Calcination: carbonate ore heated in limited air to the oxide, e.g. ZnCO₃ → ZnO + CO₂.
- Painting/oiling, galvanisation and alloying (or tin/chromium plating). Galvanisation coats iron with zinc; the zinc keeps out air and moisture and, being more reactive, corrodes in place of iron even if the coat is scratched.
Section D — Long Answer (5 marks)
- Highly reactive metals (K, Na, Ca, Mg, Al) are extracted by electrolysis of molten compounds, e.g. Al from molten Al₂O₃. Moderately reactive metals (Zn, Fe, Pb, Cu) are obtained by converting the ore to oxide (roasting/calcination) and reducing it with carbon, e.g. ZnO + C → Zn + CO. Least reactive metals (Hg, Ag, Au) are obtained by simply heating their oxides or are found native, e.g. 2HgO → 2Hg + O₂.
- (i) Metals are lustrous, malleable, ductile, sonorous and good conductors; non-metals are dull, brittle and poor conductors. (ii) Metals form basic/amphoteric oxides (4Al + 3O₂ → 2Al₂O₃); non-metals form acidic/neutral oxides (C + O₂ → CO₂). (iii) Metals above hydrogen displace H₂ from dilute acids (Zn + 2HCl → ZnCl₂ + H₂); non-metals do not. Exceptions: mercury is a liquid metal and iodine is a lustrous non-metal; graphite (a non-metal) conducts electricity.
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