CBSE Guess > Papers > Question Papers > Class X > 2009 > Science > Science

SCIENCE - 2009
Comptt
Set - I -(Delhi)

Time allowed : 2 1/2 hours
 Maximum marks : 60

General Instructions :
(i) The question paper comprises of two Sections, A and B. You are to attempt both
the Sections.
(ii) All questions are compulsory.
(iii) There is no overall choice. However, internal choice has been provided in all the
three questions of five marks category. Only one option in such questions is to be
attempted.
(iv) All questions of Section A and all questions of Section B are to be attempted
separately.
(v) Questions number 1 to 6 in Section A and 17 to 19 in Section B are short answer
type questions. These questions carry one mark each.
(vi) Questions number 7 to 10 in Section A and 20 to 24 in Section B are short answer type questions and carry two marks each.
(vii) Questions number 11 to 14 in Section A and 25 and 26 in Section B are also short answer type questions and carry three marks each.
(viii) Questions number 15 and 16 in Section A and question number 27 in Section B are long answer type questions and carry five marks each.

Section A

Q. 1. Which gas is evolved when sodium hydrogen carbonate reacts with dilute hydrochloric acid? 1

Ans. CO₂ gas is evolved when sodium hydrogen carbonate reacts with dilute hydrochloric acid.

Q. 2. Name the carbon compound which on heating with excess of concentrated sulphuric acid at 443 K gives ethene. 1

Ans. Ethanol on heating with excess of concentrated sulphuric acid at 443 K gives ethene.

Q. 3. Lithium, sodium and potassium form a Dobereiner’s triad. The atomic masses of lithium and potassium are 7 and 39 respectively. Predict the atomic mass of sodium. 1

Ans. The atomic mass of sodium is the arithmetic mean of the masses of lithium and potassium.

Science 2009 Question Papers Class X
Delhi		Outside Delhi		Compartment Delhi		Outside Delhi		Foreign
	Set 1 (PDF)		Set 1 (PDF)		Set 1		Set 1		Set 1 (PDF)
					Set 2		Set 2
					Set 3		Set 3