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.
How many moles of molecules are there in 16 g Oxygen?
A. 1 B. 0.5 C. 0.1 D. 0.05
What is mass of Carbon present in 44 g of CO,?
A. 6 g B. 12 g C. 44 g D. 24 g
What is the formula mass of CuSO4.5H20 ? (Atomic masses are Cu = 63.5, H =1,0 =16,S = 32) A. 159.5 B. 185.5 C. 249.5 D. 149.5
Number of neutrons in (_13^27)M is__________.
A. 13 B. 14 C. 27 D. 15
Which of the following sub-shells can accommodate 6 electrons?
A. s B. d C. p D. f
Rutherford used particles in his experiment
A. He atoms B. He+ C. He+2 D. He-2
The horizontal rows of the periodic table are called__________.
A. Groups B. Periods C. Sub-shells D. Shells
Valence shell electronic configuration of an element M (Atomic No. 14) is______.
A. 2s2,2p1 B. 2s2,2p2 C. 3s2,3p2 D. None of these
Which of the following is NOT TRUE about the formation of Na2S?
A. Each Sodium atom loses one electron. B. Sodium forms cations.
C. Sulphur forms anions. D. Each Sulphur atom gains one electron.
A liquid boils when its vapour pressure is___________.
A. 760 mm Hg B. 1 Pa C. 101.325 kPa D. None of these Which of the following solutions is more dilute?
A. 1 M B. 2 M C. 0.1 M D. 0.009 M
Consider the given reaction: H2S + Cl → 2HCI + S
In the above reaction, H2S behaves as a / an_______.
A. Reducing agent B. Oxidizing agent C. Electrolyte D. Catalyst
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 (Marks 33)
Q. 2 Answer any ELEVEN parts. The answer to each part should not exceed 3 to 4 lines. (11 x 3 = 33)
Write the empirical formulas for the compounds containing C to H in the following ratio:
a. 1 : 4 b. 2 : 6 c. 6 : 6
Oxygen (02) is converted to Ozone (03) during thunder storms. Calculate the mass of ozone (03) if 9.05 moles of ozone is formed in a storm.
Differentiate between Analytical chemistry and Environmental chemistry.
Write electronic configuration of the following elements:
(_14^28)Si b. (_12^24)Mg c. (_18^40)Ar
M-24 is a radioactive isotope used to diagnose restricted blood circulation. How many electrons, proton and neutrons are there in this isotope. Valence shell electronic configuration of M is 3s1
Find out the position of the following elements in the periodic table from the electronic configuration: a. Nitrogen (Atomic No. 7) b. Oxygen (Atomic No. 8).
For Aluminum (Al) and Nitrogen (N) pair of atoms, use electron dot and electron cross structures to write the equation for the formation of ionic compound.
Is evaporation a cooling process? Explain briefly.
Explain why CH3OH (Methyl alcohol or Methanol) is soluble in water but C6H6 (Benzene) is not.
A solution of calcium hydroxide Ca(OH2) is prepared by dissolving 5.2 mg of Ca(0H)2 to a total volume of 1000 cm3 . Calculate the molarity of this solution.
What is Oxidation State? Calculate the oxidation number of Cr in H2Cr04 (chromic acid).
Which of the following displacement reactions will occur and why:
a. 02(g) + 2 NaF(aq) → 2NaCl(aq) + F2(g) b. Br2(g) + 2KI(aq) → 2 KBr(aq) + I2(g) c. I2(g) + 2KBr(aq) → 2KI(aq) + Br(g)
Name two substances that are solids at 25°C .
Explain how elements attain stability.
The Isotopes of Chlorine are (_17^35)Cl and(_17^37)Cl. How do these Isotopes differ? How are they alike?
SECTION — C (Marks 20)
Note: Attempt any TWO questions. All questions carry equal marks. (2 x 10 = 20)
Q. 3 Define Covalent Bond. Explain the types of covalent bond giving two examples of each bond. (10)
Q. 4 Explain the effect of external pressure on boiling point of liquids. (10)
Q. 5 a. Explain the ways in which Oxidation and Reduction processes can be defined. Give two examples of each. (8)
b. Hydrogen peroxide (H202) reacts with Silver oxide (Ag20) and Lead (II) Sulphide according to the following equations:
H202 + Ag20 → 2Ag + H20+ 02 (ii) 4H202 + PbS → Pb504+ 4H20
Is hydrogen peroxide (H202) an oxidizing or reducing agent in the above reactions? Explain the reason. (2)