UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS General Certificate of Education Ordinary Level 5070/31 CHEMISTRY Paper 3 Practical Test October/November 2010 CONFIDENTIAL INSTRUCTIONS *4711088250* Great care should be taken to ensure that any confidential information given does not reach the candidates either directly or indirectly. The Supervisor’s attention is drawn to the form on page 7 which must be completed and returned with the scripts. If you have any problems
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I. Introduction There truly is nothing more magical than the first time you walk through an aquarium. A blue glow of light‚ the fish swimming all around you in more hughes of colors than you’ve ever imagined. The way they flirt with you on the other side of the glass‚ "hey come follow me!" they call out to you as they pass by. Because of this mysterious wonder‚ I’ve decided to start my own fish tank! First I had to grab all of my materials. My tank is a lovely 55g with a stand and lots of figurines
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are given household cleaning materials usually die due to the chemicals in them. We haven’t found a study proving that household cleaning materials have a positive effect on plant growth. One reason for these negative effects are because of the ammonia that’s in Windex and plants can take. Our group predicted that are Brassica Rapa will not be positively affected by the Windex‚ if anything they would die very soon. Materials Used During planting and Experimenting: wood stick
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_______________ NAME_________________________________________ SECTION: ______________________ Stoichiometry II - Mole Calculations/ Limiting and Excess Reagent – Lecture Notes 1. Given the balanced equation N2(g) + 3H2(g) 2NH3(g) How many moles of ammonia are produced when 0.60 mol of nitrogen reacts with hydrogen? 2. Given the equation: SiO2 + HF SiF4 + H2O a. Calculate the number of moles HF that would completely react with 2.5 moles of SiO2. b. Calculate the number of moles SiF4 formed by completely
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3. A 1% solution of sodium bicarbonate has a pH of about 8.5. 4. Yeast cells have an internal pH that is slightly acidic (about 5.5 to 6.0). Concepts • Diffusion • Active transport • Acid–base indicators • Selective permeability Materials Ammonia solution‚ NH3 ‚ 0.01 M Beaker‚ 100-mL Hydrochloric acid solution‚ HCl‚ 0.01 M Filter paper Neutral red solution‚ 0.02% Funnel Potassium hydroxide solution‚ KOH‚ 0.01 M Graduated cylinder‚ 25-mL Sodium bicarbonate solution‚ NaHCO3 ‚ 1% Pipets
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CHM130 Lab 3 Identification of Chemical Change Name: Paige Miller A. Data Table (24 points) Place your completed data table here: Reactants Predictions Before Combining Observations After Combining Starch + I2 I2 will turn Starch black I2 turned starch black Food coloring + NaOCl NaOCI will turn blue Coloring and NaOCI did not combine‚ NaOCI separated to the bottom Food coloring + CH3COOH CH3COOH will turn blue CH3COOH darkened the blue color Food coloring + NaOCl + CH3COOH Will
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separately for each Subject. Chemistry 1. Solve all the questions from HSEB question bank on the following topics:- Redox reaction Periodic Table Ammonia and Nitric acid Mole concept 2. Draw the Lewis structure of following compounds. O3‚ CO‚ HNO3‚ H2SO4‚ (NH4)2SO4‚ Ca3P2‚ Al2(SO4)3‚ KNO3 3. Prepare a term paper on “Discovery of manufacture of ammonia and subsequent awarding of Nobel Prize in 1919 to Fritz Haber and Bosch” including following points:- Percentage of Nitrogen in air and soil Importance
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increase ecological balance of nutrients in aquatic ecosystem. OVERVIEW:- Nitrate contamination The use of fertilizers to improve soil fertility and enhance plant growth has resulted in the contamination of nitrogen compounds such as ammonia‚ nitrate and nitride in our rivers‚ lakes and ocean. During soil erosion or heavy rain‚ flowing water will wash nitrates into the nearest lakes and rivers. This causes the pollution and contamination of the water. The presence of nitrates in rivers
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The Neolithic and Industrial Revolutions The two changes in the use of the earth’s resources that had the greatest effect on the world population were the Neolithic and the industrial revolutions. The Neolithic revolution (a.k.a. agricultural revolution) was a change in the way of life of our ancestors. It took place about 8000 years ago among various tribes in Asia and the Middle East. It included a transition from foraging and hunting to the domestication of animals (most probably starting
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measures the osmolarity. This is done by freezing the sample of hemolymph and the time that it takes to defrost depicts the amount of osmoles. Water analyses for the three tanks determined the temperature ºC‚ pH‚ salinity (ppt)‚ oxygen levels and the ammonia content. The temperatures of all three tanks were taken by a digital thermometer and the pH of the water was taken by a pH
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