9th Class Chemistry Past Paper 2021 Evening
Note: Chemistry 2nd Time Paper of 9th Class.
Group-II (Subjective) 48 Marks
Part– I
Q.2 Write short answers to any FIVE (5) questions: (10 Marks)
(i) Differentiate between atomic number and mass number.
(ii) What is the difference between physical and chemical properties? Give an example of each.
(iii) Why do ionic compounds have high melting and boiling points?
(iv) Write down the electronic configuration of aluminium according to shells and subshells.
(v) Differentiate between a shell and a subshell with examples.
(vi) Describe the trend of electronegativity.
(vii) Define ionization energy.
(viii) Write two features of the long form of the periodic table.
Q.3 Write short answers to any FIVE (5) questions: (10 Marks)
(i) Define octet rule and duplet rule.
(ii) Define a double covalent bond with one example.
(iii) What is hydrogen bonding?
(iv) What is absolute zero?
(v) How do intermolecular forces affect evaporation?
(vi) Define aqueous solution with one example.
(vii) What is percentage mass/volume (% m/v)?
(viii) Define saturated and unsaturated solutions.
Q.4 Write short answers to any FIVE (5) questions: (10 Marks)
(i) Define reducing agent.
(ii) What is meant by rust?
(iii) Define electrochemical cell.
(iv) What is meant by an electrolyte? Give Example.
(v) Why is copper used for making electrical wires?
(vi) Define non-metal.
(vii) What is meant by electropositivity?
(viii) Write down the reaction of fluorine with water.
PART-II
Note: Attempt any TWO (2) questions.
Q.5
(a) What were the results concluded by Rutherford in his experiment? (5 Marks)
(b) Define a molecule and explain its types. (4 Marks)
Q.6
(a) Explain dipole-dipole interaction with an example of HCl. (5 Marks)
(b) State Boyle’s law and derive its equation. (4 Marks)
Q.7
(a) Define electroplating and explain the electroplating of chromium. (5 Marks)
(b) What is molarity? Write its formula and explain how a one molar solution of sodium hydoxide (NaOH) is prepared. (4 Marks)