Answerkey2010 sa-part b
- 3. Q. 5 ____________________________________________________________________ Q.6 __________________________________________________________________ Q. 7 Answers: (a) a = 3, b = 8, c = 3, d = 2 and e = 4. (b) f = 2, g = 1, h = 1. (c) i = 2, j = 1, k = 1, l = 2 (d) 2.54 g of I2 = 1/100 mole of I2 = 2/100 gm atom of Cu % Cu = (2/100) X (63.5/2) = 63.5% _____________________________________________________________
- 4. Q. 8 Answers: Bottle A = III, Bottle B = II, Bottle C = IV, Bottle D = I CH3 CO2H NH2 CO2H NH2 Compound with the highest solubility in distilled water: IV __________________________________________________________________ Q. 9 Answers: (a) 2500 x 4.184 kJ = 10460 kJ (b) 342 g of sucrose produces 5600 kJ of energy. To provide 10460 kJ we need 10460x 342/5600 g = 638 g 638 g/342 g x 12 x 22.4 L = 501 L ______________________________________________________________________ Q.10 Answers: (a) Difference in flower color is most likely due to environmental factors (b) Perform cross breeding between the plants from Chandigarh and those from Shimla to find out whether we get any pink flower or flowers with any shade of color between pink and white in the F1 generation (c) Grow the plants from Chandigarh in Shimla and check whether they still produce white flowers or bear pink flowers _________________________________________________________________
- 5. Q.11 Answers: (a) In experiment A, ethanol fermentation occurs producing CO2, turning lime water milky. Since acid is not produced the dye colour does not change. In experiment B, lactic acid fermentation takes place, which produces acid but does not produce CO2. Hence dye colour changes to yellow but the lime water does not turn milky . In experiment C, since the lime water turns milky, ethanol fermentation is occurring. In addition, since removal of air did not affect the reaction, the fermentation is anaerobic and yeast must be the organism in the flask. (b) In RBCs, lactic acid fermentation occurs. ___________________________________________________________________ Q. 12 Answers: (a) The result of the radio-carbon dating was correct. Reason: Vehicles running on the highway beside the house emitted carbon dioxide from the combustion of petrol or diesel, which are fossil fuels. The carbon in this carbon dioxide, coming from living material that has been converted into petroleum millions of years ago, would get assimilated into the tissues of the plant as it uses carbon dioxide from the surrounding atmosphere for photosynthesis. Therefore tissues of the plant, when used for radio-carbon dating, would show the age of the plant to be many thousands of years old. (b) A simple experiment to test the validity of this explanation would be to collect seeds from the plant and grow them in a plot of land away from the highway or other sources of carbon dioxide coming from the burning of fossil fuels. Radio-carbon dating of plants growing from these seeds should show them as young plants.