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ICSE-X-Chemistry

Previous Year Paper year:2011

with Solutions -
 
  • #
    Board Paper 2011
    ICSE Board
    Class X Chemistry
    Board Paper - 2011
    Time: 1.5 hrs Total Marks: 80
    General Instructions:
    1. Answers to this paper must be written on the paper provided separately.
    2. You will NOT be allowed to write during the first 15 minutes. This time is to be spent in
    reading the question paper.
    The time given at the head of t h i s paper is the time allowed for writing the
    answers.
    This question paper is divided into two sections.
    3. Section I contains one question with parts (a) to (h); all the eight parts are to be
    answered.
    4. Section II contains six questions numbered 2 to 7. You are to answer any four of these
    questions.
    The intended marks of questions or for parts of questions are given in brackets [ ].
  • # [40]
    Section : I
    Attempt all questions from this section.
  • #1
  • #1-a [5]
    Choose from the following list of substances as to what matches the description from (i)
    to (v) given below:
    [Acetylene gas, aqua fortis, coke, brass, barium chloride, bronze, platinum].
  • #1-a-i
    i. An aqueous salt solution used for testing sulphate radical.
    Ans : Barium chloride
  • #1-a-ii
    ii. A catalyst used in the manufacture of nitric acid by Ostwald.s process.
    Ans : Platinum
  • #1-a-iii
    iii. A black powdery substance used for the reduction of zinc oxide during its
    extraction.
    Ans : Coke
  • #1-a-iv
    iv. A gaseous hydrocarbon commonly used for welding purposes.
    Ans : Acetylene gas
  • #1-a-v
    v. The substance is an alloy of zinc, copper and tin.
    Ans : Bronze
  • #1-b [5]
    What would you observe in each of the following cases?
  • #1-b-i
    i. Ammonium hydroxide is first added in a small quantity and then in excess to a
    solution of copper sulphate.
    Ans : In small quantity - a bluish white ppt is obtained.
    In excess - deep (inky) blue solution is obtained.
  • #1-b-ii
    ii. Sugar crystals are added to a hard glass test tube containing concentrated
    sulphuric acid.
    Ans : Turns to black mass called sugar charcoal.
  • #1-b-iii
    iii. Copper is heated with concentrated nitric acid in a hard glass test tube.
    Ans : A reddish brown acidic gas called nitrogen dioxide is obtained.
  • #1-b-iv
    iv. Water is added to the product formed when aluminium is burnt in a jar of nitrogen
    gas.
    Ans : Pungent smelling basic gas called ammonia is evolved.
  • #1-b-v
    v. When carbon monoxide is passed over heated copper oxide.
    Ans : Reddish metal copper is obtained.
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