Federal Board Class IX Chemistry
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. (12)
i. Name the chemist who gave the metallic concept of Sulphur and mercury.
- Abu Mansoor
- Jabir Bin Hayan
- Bu Ali Sina
ii. C₂H₂O₄ is the molecular formula of ________.
- Acetic Acid
- Carbonic Acid
- Citric Acid
- Oxalic Acid
iii. Which charge is on a neutron?
- 1.673 x 10¯¹⁹ C
- 1.76 x 10¯¹¹ C
- 9.109 x 10¯¹⁹ C
iv. What happens to the total energy when gas molecules collide with each other?
v. Lead storage battery has two electrodes. One of them is lead name the second electrode
- Magnesium oxide
- Lead Oxide
vi. What is the type of solution of Amalgam (Mercury in Silver)?
- Liquid in Liquid
- Solid in Solid
- Liquid in Solid
- Gas in Solid
vii. Which of the following is mixed with ice to lower the temperature?
viii. What is the common name of Sodium Carbonate (Na₂CO₃)?
- Baking Soda
- Washing Soda
- Caustic Soda
- Lemon Soda
ix. Burning of fuel is a chemical reation. What is its type?
- Addition Reaction
- Displacement Reaction
- Exothermic Reaction
- Endothermic Reaction
x. How many periods are there in Modern Periodic Table?
xi. What kind of bond will be formed between two atoms of Oxygen?
- Ionic Bond
- Covalent Bond
- Polar Bond
- Co-ordinate Covalent Bond
xii. Which of the following is the conjugate base of acetic acid?
Q.2. Answer any ELEVEN parts. The answer to each part should not exceed 3 to 4 lines. (33)
i. The scientific method includes four steps
a. Name these four steps
b. Draw a cyclic process of scientific method
ii. Differentiate between Empirical formula and Molecular formula?
iii. What type of forces are present between the molecules of hydrogen fluoride (HF). Define the force and show it by dotted lines.
iv. The Atomic Model was proposed by J.J. Thomson in 1904.
a. What is ‘Plum Pudding Model’?
b. What is meant by the term ‘Transmutation’?
c. What were the comments of Rutherford on his own experiment?
v. All the electrons present in the atom of an element can be allocated in different shells.
a. Write down Aufbau principle.
vi. Name any three elements that occur in liquid state at room temperature.
vii. Describe ‘Octet Rule’.
viii. Use the word give to represent the changes taking place in the following process.
a. Solid state to Liquid state
b. Liquid state to Solid state
c. Solid state to Gaseous state
d. Gaseous state to Solid state
e. Liquid state to Gaseous state
f. Gaseous state to Liquid state
ix. During the electrolysis of Sodium Chloride solution.
a. Name the electrodes used as a cathode and as an anode.
b. Name the ions move toward cathode and anode.
c. After electrolysis, the remaining solution is basic in nature. Why?
x. Differentiate between True and Colloidal Solution with the help of examples.
xi. State Faraday’s Second law of Electrolysis with its mathematical representation.
xii. Two specific salts are crystallized to form a double salt.
xiii. Define ‘Basicity of an Acid’ and ‘Acidity of a base’. Also give examples.
xiv. Heat of reaction is the heat evolved or absorbed during a chemical reaction.
a. Why a polystyrene cup is used instead of a glass beaker to find out the heat of neutralization?
b. A young man consumes 34000kj of energy for his routine activities every day. If one gram of flour provides about 17kj of energy, how much flour will he need for his daily energy requirements?
xv. State ‘Law of Multiple Proportions’
NOTE: Attempt any TWO questions. (20)
Q.3. Explain how Washing Soda / Sodium Carbonate (Na₂CO₃) is prepared on industrial scale. Also draw a flow sheet diagram for its preparation. (08 + 02)
Q.4. Define ‘Modern Periodic Law’. Write important features of Modern Periodic Table. (02 + 08)
Q.5. (a) State and explain the ‘Law of Reciprocal Propotions’. (06)
(b) Prove the law of reciprocal proportions with the help of following data. (04)
Methane gas contains 75% Carbon and 25% Hydrogen whereas Carbon dioxide contains 27.27% Carbon and 72.73% Oxygen and water contains 11.10% Hydrogen and 88.9% Oxygen.