9th Class Chemistry Past Paper 2021
Note: Chemistry 1st Time Paper of 9th Class.
Group-I (Subjective) 48 Marks
Part– I
Q.2 Write short answers to any FIVE (5) questions: (10 Marks)
(i) Write down the empirical formula of glucose and silica.
(ii) Define mole and give an example.
(iii) Define element. Write the name of an element that occurs in the liquid state.
(iv) How was the nucleus discovered by Rutherford?
(v) Define electronic configuration.
(vi) State the modern periodic law. Who put forward this law?
(vii) Write the trend of the shielding effect in the periodic table.
(viii) Why are elements of groups 1 and 2 called “S block elements”?
Q.3 Write short answers to any FIVE (5) questions: (10 Marks)
(i) Write down the names of four types of chemical bonds.
(ii) Differentiate between the donor and acceptor in a coordinate covalent bond.
(iii) How is a polar covalent bond formed?
(iv) How do intermolecular forces affect the evaporation of a liquid?
(v) How does temperature affect the vapor pressure of a liquid?
(vi) What is the difference between a saturated and an unsaturated solution?
(vii) What is meant by volume/mass %?
(viii) How can you distinguish between a solution and a pure liquid?
Q.4 Write short answers to any FIVE (5) questions: (10 Marks)
(i) What do you mean by an oxidizing agent? Give an example.
(ii) What do you mean by rust? Write its equation.
(iii) Define oxidation number.
(iv) What do you mean by a redox reaction? Give an example.
(v) Name four least reactive metals.
(vi) Write the trend of electropositivity in a group and a period.
(vii) Write any two uses of platinum.
(viii) What do you mean by non-metals?
PART-II
Note: Attempt any TWO (2) questions.
Q.5
(a) Write down any five differences between Rutherford’s atomic theory and Bohr’s atomic theory. (5 Marks)
(b) Explain compounds and give their classification. (4 Marks)
Q.6
(a) Define dipole-dipole interaction and explain it with an example. (5 Marks)
(b) Explain that evaporation is a continuous and cooling process. (4 Marks)
Q.7
(a) Define electroplating and explain the electroplating of chromium. (5 Marks)
(b) How much NaOH is required to prepare 500 cm³ of a 0.4 M solution? (4 Marks)