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.
Which of the following is a molecular ion.
A. CN- B. C ̇N C. N 3 D. .N ̇:
Which of the following isotopes is used to trace the flow of blood and detect possible constrictions or obstructions in the circulatory system?
A. Cobalt-60 B. Iodine-123 C. Carbon-14 D. Na-24
Atomic Numbers were discovered by___________.
A. Rutherford B. Moseley C. Dalton D. Bohr
In which group of the Periodic table is (_16^32)S present on the basis of electronic configuration? A. IVth A group B. VIthA group C. VIIth A group D. VIIthA group
Due to high ionization energies, which elements do NOT lose electron?
A. Metals B. Non-metals C. Transition elements D. Radioactive elements
Which of the following is Sublime?
A. HCI (Acid) B. H2S04(Acid) B. Benzonic Acid D. Calcium Carbonate
Melting point of Sodium Chloride is __________.
A. 701°C B. 801° C C. 901° C D. 1001° C
Vegetable oil is converted into vegetable ghee by passing H2 gas through the oil. In this process which of the following elements is used as a catalyst?
A. Pt B. Pb C. Ni D. Cu
What is the oxidation state of Hydrogen in case of Metallic Hydrides?
A. +1 B. -1 C. +2 D. -2
Which of the following is used as cathode in the Down’s cell?
A. Iron B. Platinum C. Graphite D. Aluminum
Which of the following is Milk of Magnesia?
A. MgO B. Mg (OH) 2 C. MgCO3 D. Mg (N03)2
In Aqua Regia. the ratio between HCl (conc) and HNO (conc) is___________.
A. 3: 1 B. 2: 1 C. 1: 3 D. 1: 2
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 three to four lines. (11 x 3 = 33)
Differentiate between Ion and Free-Radical. Give examples.
Calculate the number of atoms in the following compounds:
a. 1.25 moles of Zn b. 0.2 moles of Al.
Write any three postulates of Bohr’s atomic theory.
Chlorine has two isotopes. Draw the diagram to show the structure of isotopes of chlorine. Also write the isotope symbols for each.
Describe briefly the Shell and Sub-shell. Also relate electronic configuration with the Aufbau Principle.
In which period and group are the following elements present in the Periodic Table:
a. (_5^9)B b. (_12^24)Mg c. (_18^40)Ar
Define Ionization Energy, Electron Affinity and Atomic Size.
State Octet and Duplet rule. How does Al form a cation?
Draw electron cross and dot structure for the following molecules: a. CCl4 b. NH3 c. CO2
What is Boiling point? How does the external pressure affect the boiling point?
Define Boyles Law.
Ethene is used as anesthetic gas. When the pressure on 2.5 dm3 of ethene is changed from 1.05 to 2.10 atm, the volume of Ethene becomes 1.25 dm3 , if temperature remains constant. Explain this change using Boyle’s Law.
Differentiate between Amorphous Solids and Crystalline Solids.
If 40 gram of urea (NH2CONH2) is dissolved in water to make 500 cm3of solution then what is the Molarity of the solution.
What is Solubility? Explain the attraction of Na+ and Cl- ions for water molecules. Also draw diagram.
Compare Solution, Suspension and Colloids with one example each.
SECTION — C (Marks 20)
Note: Attempt any TWO questions. All questions carry equal marks. (2 x 10 = 20)
What are the rules for assigning oxidation state / number? (04)
Breath Alyzer contains an acidic solution of Potassium dichromate K2Cr207. Determine the oxidation state of Cr in it. (04)
What is Spontaneous process? Give its examples from daily life. (02)
Write down any four chemical equations to compare the reactivity of the Halogens. (04)
Arrange the following compounds in order of increasing acidic and Basic characters: (2+2)
HF , HI HBr , HCI (II) Be0, CaO, MgO, Sr0
What do you know about Silicon Chip? Write its uses. (02)
What is Shielding Effect? Which of the following atoms nave smaller shielding effect: (1+4)
(i) F or CI (ii) Li or Na (iii) B or Al (iv) C or Si
How is Covalent Bond formed? Write its types. Give examples for each type. Also draw diagrams. (05)