Federal Board Class IX Chemistry

SECTION “A”

Q.1. Insert the correct option i.e. A/B/C/D in the empty box provided opposite each part. Each part carries one mark.

i. Which particles are added to find the Mass Number?

• Number of electrons and number of protons
• Number of neutrons and number of protons
• Number of electrons and number of electrons
• Total number of neutrons

ii. Which of the following branches of chemistry studies all elements and their compound, except the compounds of carbon?

• Physical Chemistry
• Organic Chemistry
• Biochemistry
• Inorganic Chemistry

iii. If a liquid is boiled, its vapours are condensed. This process is called ________.

• Evaporation
• Solidification
• Condensation
• Distillation

iv. Which of the following is a weak electrolyte?

• Citric Acid
• Sulphuric Acid
• Hydrochloric Acid
• Nitric Acid

v. How the solubility of Lithium Carbonate Li₂CO₃ can be increased?

• By decreasing the temperature
• By increasing the temperature
• By decreasing the pressure
• By increasing the pressure

vi. How many grams of water is equal to 2 moles of water?

• 18 grams
• 06 grams
• 56 grams
• 36 grams

vii. In which of the following natural things the Formic Acid is present?

• Lemon
• Vinegar
• Stings of bees
• Sour milk

viii. What kind of heat is evolved by mixing equimolar volume of Sodium Hydroxide and Hydrochloric Acid?

• Heat of Vapourization
• Specific Heat
• Heat of Neutralization
• Latent heat of fusion

ix. Which of the following pairs of atoms forms a pure covalent bond?

• Hydrogen and Chlorine
• Chlorine and Chlorine
• Hydrogen and Oxygen
• Sodium and Chlorine

x. Which of the following is the most reactive metal?

• Sodium
• Potassium
• Cesium
• Calcium

xi. 44 grams of Carbon dioxide contains 6.02 x 10²³ ________.

• Moles
• Molecules
• Radicals
• Ions

xii. Which of the following is a Lewis Acid?

• NH₃
• CH₃
• AlCl₃
• CH₃COOH

SECTION “B”

Q.2. Attempt any ELEVEN parts. The answer to each part should not exceed 3 to 4 lines. (33)

i. What is meant by Artificial Radioactivity?

ii. Define isotope and draw isotopes of Nitrogen.

iii. Which elements are responsible for the different colours of hair of different people?

iv. What type of bond is formed between NH₃ and BF₃? Explain.

v. Give reason. Why?

a. On heating, liquid change into gaseous form
b. It is easy to compress air as compare to water
c. A gas neither has a fixed shape nor a fixed volume.

vi. Give reasons.

a. Is it possible to make a saturated solution of alcohol and water?
b. Is kerosene oil soluble in water?

vii. What is meant by Solubility? List any two factors that affect the Solubility.

viii. During electrolysis water ionizes into ions. Name the gases that are produced at cathode and anode. Write oxidation reaction involved in this process.

ix. What is meant by “Ionization” and “Degree of Lonization”.

x. Complete and balance the following reactions.

Na₂CO₃ + HCl ————-
Al + Fe₂O₃ —————-
Zn (NO₃)₂ —————-

xi. Phlogiston theory is about the combustible material.

a. Name the scientist who developed this theory.
b. State the theory.

xii. Define Empirical formula and draw structure of sand (SiO₂).

xiii. Benzene is represented by its empirical formula CH. While its molecular mass is 78, find out its molecular formula.

xiv. Titration is a method used to find the unknown molarity of solution.

a. What is meant by standard solution?
b. What is the sum of pH and pOH in any solution? If a solution has pH3.5 what will be its pOH.

xv. What a chemical reaction takes place in a container, heat is evolved.

a. Is this reaction “Exothermic” or “Endothermic”?
b. The container becomes hot or cold?
c. If the energy of the system will increase or decrease after the reaction.

SECTION “C”

NOTE: Attempt any TWO questions. (20)

Q.3. Define Salts. How are they classified? Explain any three of them. (10)

Q.4. Describe the construction and working of dry cell and lead storage battery. Give their uses in every day of life. (05 + 05)

Q.5. Define “Atom”. Name atomic properties of an atom. Define and explain their trends in the periodic table. (1 + 3 + 3 + 3)