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.
A compound with chemical formula Na2CX3 has formula mass 106 amu. Atomic mass of the element X is________.
A. 106 B. 23 C. 12 D. 16
The electronic configuration of an element is 1s2,2s2 . An atom of this element will form an ion that will have charge.
A. +1 B. +2 C. +3 D. -1
M shell has sub-shells.
A. 1s, 2s B. 2s, 2p C. 3s, 3p, 3d D. 1s, 2s, 3s
Which of the following elements has greater shielding effect?
A. Li B. Na C. K D. Rb
In the formation of AlF3, Al atom loses electrons.
A. 1 B. 2 C. 3 D. 4
Consider the following data:
Sr. No X Y X / Y
1 1.00 273 0.0037
2 1.37 373 0.0037
3 1.73 473 0.0037
4 2.10 573 0.0037
Which of the following relationships does the above table represent?
X ∝ y B. x = y C. x ∝ 1/y D. x = 1/y
A solution of NaOH has a concentration of 4g/dm3. What is the mass of NaOH contained in 250cm3of this solution?
A. 40 g B. 20 g C. 1 g D. 2 g
Which of the following elements in the given reaction is reduced: Zn0+H2→Zn+H20
A. H2 B. ZnO C. Zn D. O
Galvanizing is coating with __________.
A. Sn B. Zn C. Cr D. Cu
Which of the following is an amphoteric oxide?
A Na20 . B. Al2O3 C. MgO D. S02
Silicon belongs to group IV A. It has______ electrons in the valence shell.
A. 2 B. 3 C. 4 D. 6
The branch of Chemistry that deals with substances containing carbon is called
A. Inorganic Chemistry B. Physical Chemistry C. Industrial Chemistry D. Organic Chemistry
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 )
Differentiate between the following: a. Atom and Ion b. Molecular ion and Free radical
Calculate the mass of 3.24 x 1018 atoms of Iron.
Define Mixture and Compound.
Differentiate between Shells and Sub-shells.
Define Ionization Energy. Write the trend of Ionization energy in group and period.
Define Isotopes. Draw atomic structures of the Isotopes of Carbon.
Explain briefly the formation of Covalent bond between two Nitrogen atoms.
Describe briefly the formation of Mg+2 and Na+ cations.
The boiling point of water on the top of Mount Everest is 70°C while at Murree it is 98°C . Explain the difference.
The following table shows data of volume of a gas and its temperature for the given mass of a gas at 900 mmHg
Temperature – Volume data for a gas at 900 mm of Hg.
Temperature (° C) 0 5 10 15 20
Volume (cm3) 107.9 109.7 111.7 113.6 115.5
Explain volume – temperature relationship using Charles’s law.
Differentiate among Saturated, Unsaturated and Supersaturated solutions giving one example of each.
Define Oxidation and Reduction processes in terms of loss or gain of electrons.
Define the following properties of gases: a. Diffusion b. Effusion
Urea ((NH2 )2C0) is a white solid, used as fertilizer and starting material for synthetic plastic. A solution contains 40 g of urea dissolved in 500cm3 of solution. Calculate the molarity of the solution.
Which of the following displacement reaction will not occur? Also give reason:
a. Cl2 +2NaF →2NaCl + F2 b. Br2 +2KI→ 2KBr + I2 c. I2 + 2KBr→ 2 KI + Br2
SECTION — C (Marks 20)
Note: Attempt any TWO questions. All questions carry equal marks. (2 x 10 = 20)
Q.3 Describe the Rutherford’s atomic model. What are the defects in this atomic model? (10)
Q.4 a. Define Solubility. What is the effect of temperature on solubility? Explain by giving examples. (08)
b. Which of the following pairs of liquid are miscible: (I) Water and Benzene (ii) Benzene and Carbon tetrachloride (C04) (iii) An oil and Benzene (02)
Q.5 a. Describe the manufacturing of Sodium Hydroxide (NaOH) from Brine. Write all the chemical reactions occurring in the electrolytic (Nelson’s) cell. (08)
b. Boric acid H3BO3 is used in eye wash. What is the oxidation state of B in this acid? (02)