Pattern : New Pattern For 2008 Question Papers

 Very short answer questions: These are to be answered in one word or one sentence.

Question: Give an example of photochemical reactions.

Answer: Photosynthesis / Photography
Short answer questions (30-40 words): These are to be answered in 30 – 40 words.

Question: Allotropy is a property shown by which class of substances, elements, compounds or mixtures ? Give one example of allotropy.

Answer:

(i) Elements

(ii) Any one of the following :—

Red and Yellow Phosphorus

Rhombic and monoclinic Sulphur

Diamond and graphite Carbon

Short answer questions (40-50 words): These are to be answered in 40 – 50 words.

Question:

(i) Distinguish between an addition polymer and a condensation polymer.

(ii) Choose one condensation polymer and one addition polymer from amongst the following :

nylon, teflon, neoprene, polyester

(iii) Write a chemical equation for the reaction involved in the formation of a polyamide.

Answer:

(i) Addition Polymers : They are formed by addition reactions of unsaturated monomers.

Condensation Polymers : They are formed through condensation reaction of the monomers with the elimination of small molecules such as water.

(ii) Addition Polymer : Teflon / Neoprene

Condensation Polymer : Polyester / Nylon

(iii) Hexamethylene diamine + Adipic acid -> Polyamide + water

Long answer questions: These are to be answered in at least 70 words.

Question:

(a) What are 'magnetic field lines' ? How is the direction of a magnetic field at a point determiend ?

(b) Draw two field lines around a bar magnet along its length on its two sides and mark the field directions on them by arrow marks.

(c) List any three properties of magnetic field lines.

Answer:

(a) A magnetic field line is a path along which a free north pole tends to move     1 mark

Direction - is determined by a magnetic compass. The direction in which the north pole of the compass points gives the direction of magnetic field line.      ½ mark

(b) Any two lines one above and one below :–



(c) Properties of magnetic field lines.

(i) direction of field lines is from North to South pole.

(ii) No two field lines intersect

(iii) Degree of closeness of the field lines indicates the strength of the magnetic field.