CHEMISTRY SSC- I
SECTION — A (Marks 12)
Time allowed: 20 Minutes
NOTE:- Section-A is compulsory. All parts of this section are to be answered on the question paper itself. It should be completed in the first 20 minutes and handed over to the Centre Superintendent Deleting/overwriting is not allowed. Do not use lead pencil.
SECTION — A (Marks 12)
Q. 1 Circle the correct option i.e. A/B/C/ D. Each part carries one mark.
(I) The number of moles in 46 gms of sodium (Na) will be:
A. 1.5 moles B. 2 moles C. 2.5 moles D. 3 moles
(II) The natural abundance of chlorine-35 is:
A. 65% B. 25% C. 75% D. 95%
(III) The correct electronic configuration of atom having atomic number ’13’ is _____.
A. 1S2, 2S2, 2P6,3S2,3P2 B. IS2,2S2,2P6,3S2.3P1
C. 1S2,2P6,3S2,3P3 D. 1S2,2S2,3S2,3P6,4S’
(IV) The increase in ionization energy from left to right in a period is due to:
A. Decrease in nuclear charge B. Increase in nuclear charge
C. Increase in shielding effect D. Decrease in shielding effect
(V) Which one of the following obeys Duplet rule?
A. 02 B. N2 C. F2 D. H2
(VI) Which substance does not have ionic bond?
A. CH2 B. NaCI C. NaF D. MgO
(VII) Relationship “PV =Constant” represents:
A. Avogadro’s Law B. Boyle’s Law
C. Charle’s Law D. General gas equation
(VIII) Which of the following substances is sublimate?
A. Sodium Carbonate B. Calcium Chloride.
C. Ammonium Chloride D. Sodium Hydroxide
(IX) When Arshad dissolves 28 gms of KOH in one (dm)3 of water. Its molarity will be_______
A. 0.1 M B. 0.5 M C. 0.2 M D. 1 M
(X) Oxidation number of Mn in KMnO4 is:
A. – 2 B. +2 C. – 7 D. +7
(XI) SO2 is____________ oxide.
A. Strongly basic B. Strongly acidic C. Weakly acidic D. Amphoteric
(XII) In chromium plating the H2SO4 is added to Cr2(SO4)2 in order to:
A. Increase electrolytic power B. Increase hydrolysis process
C. Prevent hydrolysis D. Make Cr neutral
For Examiner’s use only:
CHEMISTRY SSC – I
Time allowed: 2:40 Hours Total Marks Sections B and C: 43
NOTE: – Answer any nine parts from Section ‘B’ and any two questions from Section ‘C’ on the separately provided answer book. Use supplementary answer sheet i.e. Sheet-B if required. Write your answers neatly and legibly. (Graph paper may be provided)
SECTION — B (Merits 33)
Q. 2 Answer any ELEVEN parts. The answer to each part should not exceed 3 to 4 lines. (11 x 3 = 33)
(I) Define Analytical Chemistry, Free Radical and Relative Atomic Mass.
(II) Calculate the mass of 2x 1025 molecules of water (H=1, 0=16).
(III) Write electronic configuration and period number of carbon (06), its group number is (04). Also write electronic configuration and group number of Argon (18), its period number is (03).
(IV) Define Group and Period of the periodic table. What are called the elements of group VIII A and why?
(V) Why Electron Affinity increases along a period and decreases from top to button along a group?
(VI) Give three reasons of chemical bonds formation.
(VII) Describe the formation of Mg++cation with the help of electronic configuration and electron dot structure.
(VIII) What is difference between Dipole — Dipole Interaction and Hydrogen Bonding? Give one example for each.
(IX) A bacterial culture isolated from sewage produces 36.4 cm3 of methane (CH4) gas at 27°C’ and 760 mm Hg Pressure. This gas occupies 33.124cm3 at 0 °C’and same pressure. Explain volume — temperature relationship from this data.
(X) Define crystalline solids. Write two properties of crystalline solids.
(XI) Fill in the missing spaces:
Solute Solvent State of resulting Solution Examples
– Liquid – Soda water
Liquid Gas Gas –
(XII) Calculate the number of moles of solute present in 1.25cm3 of 0.5 M H3PO4 solution.
(XIII) Describe rules for assigning oxidation states.
(XIV) Draw labelled diagram of a dry cell.
(XV) Keeping in view the decrease in Oxidizing power, complete the following equations:
a. F2(g) +2KCl(aq) → b. Cl2 (g) + KBr(aq) → c. Cl2(g) + NaCl(aq) →
SECTION — C (Marks 20)
Note: Attempt any TWO questions. All questions carry equal marks. (2 x 10 = 20)
Q. 3 a. Explain any three methods for the prevention of corrosion. (06)
b. What Model of an atom was proposed by Rutherford? Describe this model. Also write defects in Rutherford’s Atomic Model. (04)
O.4 a. Define solubility. Write a comprehensive note on effects of temperature on solubility of different solutes. Also draw graph to support your answer. (07)
b. Write a note on allotropes of phosphorous. (03)
O.5 a. Write a comprehensive note on “Effects of External Pressure on Boiling Point of Liquids.” (05)
b. Define Isotopes. Write uses of Isotopes in our daily life. (05)