Grade 9 Chemistry Examination
Total Marks: 80
Time: 2 Hours
Section A
(Attempt all the Questions in this Section)
Q.1 Multiple Choice Questions (15 Marks)
Choose the correct answer from the given options. (Write only the correct option)
1. Which of the following is the correct chemical formula for Zincate ion? a) ZnO22-
b) ZnO22+
c) ZnO23+
d) ZnO21-
2. What is the molecular weight of C2H5OH? (Atomic weight: C = 12, H = 1, O = 16)
a) 56 amu
b) 112 amu
c) 46 amu
d) 36 amu
3. What is the colour of precipitate obtained on the reaction of copper sulfate with
NaOH?
a) White
b) Pale blue
c) Reddish brown
d) Green
4. The atomic number of Carbon is ____.
a) 4
b) 6
c) 8
d) 10
5. The charge on a sulfate ion is:
a) -1
b) -2
c) +1
d) +2
6. Sodium chloride is held together by which type of bond?
a) Covalent
b) Ionic
c) Metallic
d) Hydrogen
7. The chemical formula for quicklime is:
a) CaCO3
b) Ca(OH)2
c) CaO
d) CaCl2
8. Hydrogen exists as a:
a) Monoatomic gas
b) Diatomic gas
c) Triatomic gas
d) Polyatomic gas
9. The law that states that the volume of a gas is inversely proportional to its pressure is:
a) Boyle’s Law
b) Charles’ Law
c) Avogadro’s Law
d) Dalton’s Law
10. The gas responsible for acid rain is:
a) CO2
b) SO2
c) O2
d) N2
11. The scientist who proposed the atomic theory is:
a) Mendeleev
b) Dalton
c) Rutherford
d) Bohr
12. The number of valence electrons in an oxygen atom is:
a) 2
b) 4
c) 6
d) 8
13. The pH value of pure water is:
a) 5
b) 7
c) 9
d) 11
14. The element with atomic number 1 is:
a) Helium
b) Hydrogen
c) Oxygen
d) Nitrogen
15. Which gas is known as "laughing gas"?
a) Oxygen
b) Carbon dioxide
c) Nitrous oxide
d) Hydrogen
Q.2 (5 sub-questions of 5 marks each - Total 25 Marks)
(A) Name the following:
1. A hygroscopic substance.
2. Chemical name of NaAlO2.
3. Metal with valency 3.
4. An anhydrous compound.
5. The element with 6 electrons in the 'l' shell.
(B) Match the following:
Column A Column B
A substance whose solubility decreases with increase in temperature a) Mg(HCO3)2
Element with atomic number 11 and 12 neutrons b) Sodium
Present in temporary hard water c) Na2CO3
A deliquescent alkali d) NaOH
Substance used for removal of hardness from water e) CaSO4
(C) Write balanced chemical equations for the following reactions:
1. Heating of hydrated copper sulfate.
2. Decomposition of glucose.
3. Reaction of basic oxide with carbon dioxide.
4. Electrolysis of water.
5. Thermal decomposition of mercury (II) carbonate.
(D) True or False (Correct if False):
1. Sodium chloride is a covalent compound.
2. Metals form anions by gaining electrons.
3. All gases obey Boyle’s Law at all temperatures.
4. Hydrogen gas is heavier than oxygen.
5. Isotopes have the same number of neutrons.
(E) Fill in the blanks:
1. The valency of Phosphorus in PCl3 is _______.
2. The gas evolved when copper (II) nitrate undergoes thermal decomposition is
_______.
3. The electron capacity of the N-shell is _______.
4. The metal that does not react with water at room temperature is _______.
5. _______ is used to remove permanent hardness from water.
Section B
(Attempt any four questions from this section)
Q.3 (Total Marks: 10)
(A) Two questions of 3 marks each
1. What is the valency of metal M in MCl? Write the formula of its sulfate and
hydroxide.
2. Differentiate between deliquescent and hygroscopic substances with examples.
(B) Answer the following (4 Marks)
1. Explain the characteristics of a true solution.
Q.4 (Total Marks: 10)
(A) Two questions of 3 marks each
1. State the modern periodic law. How does it differ from Mendeleev’s periodic law?
2. Explain why noble gases are chemically inert.
(B) Answer the following (4 Marks)
1. Describe the structure of an atom according to Bohr’s model.
Q.5 (Total Marks: 10)
(A) Two questions of 3 marks each
1. Define electrolysis. Give an example of an electrolysis reaction.
2. Write the electron configuration of Na and Cl. Explain how NaCl is formed.
(B) Answer the following (4 Marks)
1. Discuss the importance of balancing chemical equations. Balance: Fe + HCl → FeCl3
+ H2.
Q.6 (Total Marks: 10)
(A) Two questions of 3 marks each
1. What are isotopes? Give two examples.
2. Explain Boyle’s law with an example.
(B) Answer the following (4 Marks)
1. Describe the greenhouse effect and list two greenhouse gases.
Q.7 (Total Marks: 10)
(A) Two questions of 3 marks each
1. What is the pH scale? What does a pH value indicate?
2. Describe the test for hydrogen gas.
(B) Answer the following (4 Marks)
1. Explain how atmospheric pollution affects human health.
Q.8 (Total Marks: 10)
(A) Two questions of 3 marks each
1. What are the different types of chemical reactions? Give an example of each.
2. Why does ice float on water? Explain in terms of density.
(B) Answer the following (4 Marks)
1. Describe the laboratory preparation of hydrogen gas.
