CBSE Board Students Helpline

1. Consider the reaction: ZnO+ C ® Zn+CO (a)Name its type; (b) Name the oxidizing & reducing agents. [1] 2. Translate & balance the following: [1] (a ) Hydrogen gas combines with nitrogen to give ammonia; (b) Barium chloride reacts with Alu minium Sulphate ® ________ (complete it!). 3. Write the chemical name of Washing Soda & Bleaching powder. [1] 4. Write name of functional groups in RCOOR’ & RCH 2 R’. [1] 5 Out of a bulb 40W-220V and 100W-220V which one would glow brigh ter when connected in series? (show working of your answer )[1] 6. Define Chlor alk ali [1] 7. State Joule’s law of heating. [ 1 ] 8.State the conditions when it is possible to obtain a real image from a convex mirror .Suppose the f

Sample Paper – 2009 Class – X Subject – Science   GENERAL INSTRUCTIONS:   The question paper comprises two section A and B. you are two attempt both the sections. All questions are compulsory. There is no over all choices However, internal choices has been provided in three questions of five marks in section A and B. you have to attempt one option only in these questions. Marks allotted to each question are indicated against it. Question 1 to 6 in section A and 17 to 19 in section B is very short answer questions. Question 7 to 10 in section A and 20 to 24 in section B are short answer questions. Question 11 to 14 in section A and 25, 26 in section B are also short answer questions. Question 15, 16 in section A and 27 in section B are long answer questions.                                                                         SECTION – A     Identify the Oxidizing and Reducing agent in the given chemical reaction SO2   +   2H2S                    3S   +    2H2 O                      

Sample Paper – 2009 Class – X Subject – Science   GENERAL INSTRUCTIONS:   The question paper comprises two section A and B. you are two attempt both the sections. All questions are compulsory. There is no over all choices However, internal choices has been provided in three questions of five marks in section A and B. you have to attempt one option only in these questions. Marks allotted to each question are indicated against it. Question 1 to 6 in section A and 17 to 19 in section B is very short answer questions. Question 7 to 10 in section A and 20 to 24 in section B are short answer questions. Question 11 to 14 in section A and 25, 26 in section B are also short answer questions. Question 15, 16 in section A and 27 in section B are long answer questions.                                                                         SECTION – A     Identify the Oxidizing and Reducing agent in the given chemical reaction SO2   +   2H2S                    3S   +    2H2 O