1. Choose the correct answer for each from the given options: (17)
(i) The bond between hydrogen and chlorine in HCI is:
(ii) The process in which a solid directly changes to vapors is known as:
(iii) The air we breathe in usually contains a higher proportion of:
(iv) Mendeleev’s Periodic Table contains periods:
(v) The non-crystalline form of sulphur is:
(vi) China clay is used in the making of:
(vii) The heaviest of the following particles is:
(viii) The formation of water from H2 and 0 2 is an example of:
None of them
(ix) 44 a.m.u. of CO2 is equal to its:
(x) An ionic compound formed by the neutralization of an acid by a base is called:
(xi) The formula of Epsom salt is:
Mg 504 • 7H20
(Xii) The electrolyte used in lead storage battery is dilute:
(xiii) It is used in shoe polish to provide shine to the shoes:
(xiv) The sum of the mole fractions of a solute and solvent is equal to
(xv) The impure iron obtained from the blast furnace is known as
(xvi) A coordinate covalent bond is always formed between the two:
like and unlike atoms
(xvii) The first member of alkene series is:
Chemistry Past Paper 9th Class 2010 Karachi Board
SECTION “B” (SHORT-ANSWER QUESTIONS)(42)
NOTE: Answer 14 questions from this section.
2. Name three scientists of the modern period and write one contribution of each of in the field of Chemistry.
3. Define the following types of chemical reactions and give one example of each of them with a balanced chemical equation: (i) Decomposition reaction (ii) Single-Displacement reaction (iii) Combustion reaction
4. Balance the following equations:
(i) Na + H2O -+ NaOH + H2
(ii) KNO3 -+ KNO2 + Q2
(iii) NH3 + 02 -+ NO2 + H2O
5. Name the three types of radioactive rays and write one characteristic of each.
6. Define the following: (i) Fusion (ii) Sublimation (iii) Diffusion
7. Define Molarity and calculate the molarity of a solution that contains 20gm of NaOH in 500ml of the solution. (Atomic Masses: Na = 23, 0 = 16, H = I)
8. Define the following: (i) Ampere (ii) Coulomb (iii) Equivalent Mass
9. State Bronsted-Lowry concept of acids and bases and explain it with the example of HCI (as an acid) and H20 (as a base).
10. Write three important uses of Epsom salt.
11. Define a Mole. Calculate no. of moles in 50gm of H20.
12. Write the chemical formulae of the following substances. (i) Washing soda (ii) Baking soda (iii) Caustic soda
13. Define Exothermic and Endothermic reactions and write one example of each with a balanced chemical equation
14. Write chemical reaction of water with the following elements with balanced chemical equations: (i) Magnesium (ii) Chlorine (iii) Silicon
15. Compare three physical properties of each of Diamond and Graphite.
16. Define Ozone. How can ozone be prepared from oxygen? Write its two important uses.
Write three general properties of Transition Elements.
17. Write three differences between Oxidation & Reduction.
18. Write three important uses of hydrogen.
19. Give the chemical formulae of the following ones: (i) Bauxite (iii) Haematite (iii) Iron pyrite
20. Why is Methane called Marsh Gas? Write two methods for the preparation of methane gas giving balanced equation.
Define Soft water, Hard water, and Heavy water.
21 . Write the composition and one use of each of the following alloys:(i) Brass (iii) Bronze (iii) Nichrome
22. What are Soaps? Describe the two raw materials used in the preparation of soap.
Chemistry Past Paper 9th Class 2010 Karachi Board
SECTION ‘C’ (DETAILED-ANSWER QUESTIONS)(26)
NOTE: Attempt 2 questions from this section.
23.(a) Define Allotropy. Name the allotropic forms of sulphur and give two properties of each of them.
Define Electroplating. Describe nickel plating (No diagram is required)
(b) State Faraday’s First and Second Laws of Electrolysis.
(c) Name the Alkali Metals of group IA of the Periodic Table and write their three general properties.
24.(a) Describe how sulphur is extracted from underground deposits by Frasch Process. Explain it with a labeled diagram.
(b) State the following: (i) Law of Constant Composition (ii) Law of Multiple Proportions (iii) Graham’s Law of Diffusion of Gases (iv) Newland’s Law of Octaves (c) Describe the extraction of iron from its hematite one in the blast furnace (Diagram is not required).
(i) Law of Constant Composition (ii) Law of Multiple Proportions (iii) Graham’s Law of Diffusion of Gases (iv) Newland’s Law of Octaves
(ii) Law of Multiple Proportions (iii) Graham’s Law of Diffusion of Gases (iv) Newland’s Law of Octaves
(iii) Graham’s Law of Diffusion of Gases (iv) Newland’s Law of Octaves
(iv) Newland’s Law of Octaves
(c) Describe the extraction of iron from its hematite one in the blast furnace (Diagram is not required). Also, write the balanced chemical equations for the reactions which take place in the blast furnace.
25.(a) Describe the Laboratory method for the preparation of chlorine with a balanced chemical equation and draw a labeled diagram.
(b) Write four points of physical difference between Metals and Non-Metals.
(c) Define a salt & describe the 3 group of salt with example