SECOND PRELIMINARY EXAMINATION 2020-2021 STD: X TIME: 2 hrs. CHEMISTRY DATE: 16.02.2021 SCIENCE Paper 2 MARKS: 80 Answer to this paper must be written on the paper provided separately. 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 this paper is the time allowed for writing the answers. This paper is divided into two sections. Attempt all the questions from section I and any four questions from section II. The intended marks for questions or parts of questions are given in brackets . This paper consists of six printed pages. Nothing should be written on the question paper. Section I (40 marks) Attempt all questions from this section. Question 1 a) Choose the most appropriate answer from the following options:  i) Among the period 2 elements, the element which has high electron affinity is A. Lithium B. Carbon C. Chlorine D. Fluorine ii) Among the following compounds, identify the compound which has all three bonds (ionic, covalent and coordinate bond). A. Ammonia B. Ammonium chloride C. Sodium hydroxide D. Calcium chloride iii) Identify the statement which is incorrect about alkanes: A. They are hydrocarbons. B. There is a single covalent bond between carbon and hydrogen. C. They can undergo both substitution as well as addition reactions. D. On complete combustion, they produce carbon dioxide and water. iv) Which of these will act as a non-electrolyte? A. Liquid carbon tetrachloride C. Sodium hydroxide aqueous solution acid B. Acetic acid D. Potassium chloride aqueous solution v) Which one of the following will not produce an acid when made to react with water? A. Carbon monoxide B. Carbon dioxide C. Nitrogen dioxide D. Sulphur trioxide 1 Cont d on page 2
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