9th Class Chemistry Past Paper 2015 Evening
Note: Chemistry 2nd Time Paper of 9th Class.
Group-II (Subjective) 63 Marks
Part– I
Q.2 Write short answers to any FIVE (5) questions: (10 Marks)
(i) Define Organic and Inorganic Chemistry.
(ii) Define diatomic and heteroatomic molecules and give one example of each.
(iii) Find out the number of molecules in 9 grams of water.
(iv) Write the electronic configuration of phosphorus ion 3115P3- and determine the number of neutrons in it.
(v) For what purpose is U-235 used?
(vi) What are the defects of Rutherford’s atomic model?
(vii) Describe Dobereiner’s classification of triads and give one example.
(viii) Define the shielding effect. Describe its trend along a period.
Q.2 Write short answers to any FIVE (5) questions: (12 Marks)
(i) What are the elements arranged in groups 3 to 12 called?
(ii) Why does a covalent bond become polar?
(iii) Define diffusion.
(iv) What is absolute zero temperature?
(v) What is allotropy?
(vi) Give an example of a solution in which the solute is liquid and the solvent is gas.
(vii) How is a one molar solution prepared?
(viii) Define vapour pressure.
(ix) Define colloid.
Q.2 Write short answers to any FIVE (5) questions: (10 Marks)
(i) Define oxidation state with an example.
(ii) Define redox reactions.
(iii) Find out the oxidation number of nitrogen in HNO3 when: H=-1, O=-2.
(iv) Define weak electrolytes and give an example.
(v) How are the half-cells of a galvanic cell connected? What is the function of salt bridge?
(vi)Define matallic character and give an example.
(vii) Write down two uses of gold.
(viii) Why is platinum used for making jewelry?
PART-II
Note: Attempt any three (3) questions.
Q.5
(a) Write down any three differences between atomic number and mass number. (3 Marks)
(b) Describe Rutherford’s atomic model. (4 Marks)
Q.6
(a) Define a group and explain its significance in the periodic table. (3 Marks)
(b) Define a covalent bond and write its types with one example of each. (4 Marks)
Q.7
(a) Differentiate between amorphous solids and crystalline solids. (3 Marks)
(b) Discuss the effect of temperature on solubility. (4 Marks)
Q.8
(a) Differentiate between oxidizing agents and reducing agents with an example. (3 Marks)
(b) Write down four chemical properties of metals. (4 Marks)
Q.9
(a) Define a saturated solution. How is it prepared? (3 Marks)
(b) Give a comparison of electrolytic and galvanic cells. (4 Marks)