Surname Centre No. Candidate No. Paper Reference(s) Initial(s) Paper Reference Signature 7 0 4 0 7040/02 0 2 Examiner’s use only London Examinations GCE Biology Ordinary Level Paper 2 Friday 18 January 2008 – Afternoon Time: 2 hours Team Leader’s use only Question Leave Number Blank 1 2 3 4 5 Materials required for examination Nil Items included with question papers Nil 6 7 8 Instructions to Candidates In the boxes above‚ write your centre number‚ candidate
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salts that will be used to predict lattice energy again by using Hess’ Law. Heat may increase during experiment and undergo exothermic reaction. Analysis: Q = m c (Tf - Ti) = 27.9°C – 21.3°C = 6.6°C Q = (101.81g)(4180kJ/g°C)(6.6°C) Q = 2808734 kJ Discussion: Measurements were relatively accurate and closely linked to quantitative values. When measurement was a little higher‚ value resulted a little higher. The Styrofoam for this experiment was necessary because it insulates leading to less
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Point: 1373 KBoiling Point: 3273 KDensity: 7.23 g/cm^3Color of Element in its Standard Phase: A metallic silverState of Matter at Standard Temperature: SolidPhysical Properties: Member of the Lanthanide Family Heat of Vaporization: 289 kJ/mol Molar Volume: 19.95 cm^3/mole Chemical Properties: Electronegativity: -1.13 (Pauling)‚ -1.07 (Allrod Ronchow) 9 isotopes All isotopes are radioactive Isotopes: 9 isotopes‚ although none of them are stableWho Discovered
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formula: Nu = 0.023 Re 0.8 Pr 0.3 For pulsating flow‚ assume h is 2 times the value obtained from this formula. Prandtl Number Pr = 0.6 Mass flow rate of exhaust gasses = 0.250 kg/s Internal diameter of exhaust pipe = 6 cm Cp of exhaust gasses 1.08 kJ/kg K Density of exhaust gasses = 0.494 kg/m3 Dynamic viscosity of exhaust gasses = 3.32E-5 kg/m s Thermal conductivity of exhaust gasses = 5.26E-5 kW/m K Total length of exhaust pipe = 1.8 m Initial exhaust gas temperature = 483o C Temperature of exhaust
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formula). These bonds can undergo hydrolysis to yield either a molecule of ADP (adenosine diphosphate) and inorganic phosphate or a molecule of AMP (adenosine monophosphate) and pyrophosphate. Both these reactions yield a large amount of energy (about 30.6 kJ mol–1) that is used to bring about such biological processes as muscle contraction‚ the active transport of ions and molecules across plasma membranes‚ and the synthesis of biomolecules. The reactions bringing about these processes often involve the
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and easily available. vi)Have moderate rate of combustion 5 CALORIFIC VALUE: The amount of heat energy released on complete combustion of 1 kg of a fuel in air or oxygen is called its calorific value. It is expressed in kJ/kg. Hydrogen has the highest calorificvalue :150000 KJ/Kg. * Table of calorific value of different fuels is given on pg 73 of the NCERT book. 6 CONDITIONS NECESSARY FOR COMBUSTION: a)Presence of oxygen or air b)Presence of combustible substance c)Correct ignition temperature
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3 Work‚ Power and Energy At the end of this section you should be able to: a. b. c. d. e. f. describe potential energy as energy due to position and derive potential energy as mgh describe kinetic energy as energy due to motion and derive kinetic energy as mv2/2 state conservation of energy laws and solve problems where energy is conserved define power as rate of energy transfer define couple‚ torque and calculate work done by variable force or torque solve problems where energy is lost due to friction
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Introduction For this experiment‚ we are going to determine the effect of temperature on solubility‚ to be done in a chemical by dissolving a solute in a definite amount of solution which is saturated. Specifically‚ the goal of this experiment is to prepare a saturated solution of Na2C2O4 in water at different temperatures‚ determine the effect of temperature in solubility‚ and to apply Le Chatelier’s Principle. We can do all this by simply titrating a certain amount of standard KMnO4‚ and measuring
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from 80.16 - 88.20%; carbohydrate values from 53.29 - 59.01%; and calorific values ranged from 1344.00 – 1399.00 kJ/g (316.66-329.76 cal/g) for the sweet potato leaves. For M. oleifera leaves‚ crude protein was 27.51%‚ crude fibre was 19.25%‚ crude fat was 2.23%‚ ash content was 7.13%‚ moisture content was 76.53%‚ carbohydrate content was 43.88%‚ and the calorific value was 1296.00 kJ/g (305.62 cal/g). Elemental analysis of the leaves in mg/100g dry matter (DM) indicates the sweet potato leaves
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boiler surface and the surroundings. By Newton’s law of cooling it is assumed constant. The 1st law balance for the boiler at time t (secs) is + Rate of change of internal energy of the boiler and contents. Therefore‚ Where MC (kJ/ K) is the heat capacity of the boiler which in this simplified development is assumed constant. So‚ when being heated‚ (1) and when cooling‚ (2) At a value of T1 on the lot of the measured heating curve and at a value T2
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