Sample Questions 1. In the chemical formula for ammonia‚ NH3‚ what does the subscript 3 represent? (a) the number of ammonia molecules that will bond together (b) the number of nitrogen atoms in each molecule of ammonia (c) the number of nitrogen and hydrogen atoms in each molecule of ammonia (d) The number of hydrogen atoms in each molecule of ammonia 2. The diagram above shows a block from the periodic table. The number six represents the following consumers eats only producers? (a) atomic
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GITARATTAN JINDAL PUBLIC SCHOOL ROHINI‚ DELHI-110085 ASSIGNMENT – 2 (2013-14) Acids‚ Bases and Salts CLASS Q1. :X SUBJECT : Chemistry What happens when chlorine is passed over slaked lime at 313 K? Write chemical equation of the reaction involved and state two uses of the product obtained. Q2. Write the scientific name and chemical formula of plaster of paris. What happens when water is added to it? Write chemical equation for the reaction and state one property of the product
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Add the resulting extract to the first extract (in the second centrifuge tube). Now wash (microscale) the combined extracts with saturated NaCl solution (5mL)‚ then with 10% aqueous potassium carbonate (5mL)‚ then with saturated NaCl solution (5 mL) again. Dry the organic layer with anhydrous sodium sulfate. Decant the organic layer into a small beaker and concentrate to roughly 0.2 mL by evaporation in the hood (do not apply heat!). If the sample goes to dryness‚ re-dissolve in hexane (0.2 mL)
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concentration of methanoic acid which is 10 times greater than that of the bromine we can assume that the concentration of methanoic acid is constant throughout the experiment. method 1) Set up the colorimeter according to the instructions. Select a blue or green filter. 2) While you are waiting‚ prepare a results table with TIME in seconds and ABSORBANCE (in relative units). You are going to read the absorbance after 15‚ 30‚ 45 seconds‚ etc. until you have about 9 or 10 readings. 3) Fill a sample tube
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This purpose of the lab was to observe and compare the reactivity of the elements within groups and the reactivity of the groups themselves. The elements of each group were reacted with fire‚ acid (HCl or HNO3)‚ or in deionized water. According to the observations‚ the most reactive group was the alkali metals. Since the alkali metals are in group 1‚ they only have one valence electron and can easily lose this electron. As you move towards the right of the periodic table‚ the number of electrons
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1_____2_____3_____4_____5_____6_____7_____8_____9_____TOTAL________ CHEM 237‚ FALL 2007 HOUR EXAM 1 Name________________________________________________________ TA Name _______________________ __& Section # _________________ Student #______________________________________________________ 1. (9 pts) Write a valid Lewis structure for each of the following. Show lone pairs and formal charges where necessary. Draw covalent bonds as lines. (a) bisulfate ion‚ HSO4- O HO S O (b) hydrogen cyanide‚ HCN O H
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Appendix APPENDIX 1 Chemical tests for functional groups Homologous series/ Typical compound Functional group(s) Alkanes CH3CH3 ethane C – C and C–H Alkenes CH2 = CH2 ethene C=C Chemical tests/Observations Add liquid bromine in ultraviolet light (or sunlight): White fumes of HBr liberated; decolourisation of bromine occurs slowly (a) Add Br2 in CCl4 at room temperature: Decolourisation of bromine occurs immediately CH2 = CH2 + Br2 → CH2BrCH2Br (b) Add acidified
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1. (a) The diagram below represents the industrial fractional distillation of crude oil. (i) Identify fraction A. (ii) What property of the fractions allows them to be separated in the column? (2) (b) A gas oil fraction from the distillation of crude oil contains hydrocarbons in the C15 to C19 range. These hydrocarbons can be cracked by strong heating. (i) Write the molecular formula for the alkane with 19 carbon atoms. (ii) Name the type of reaction involved in cracking. (iii) Write
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Contact Hours : : : : : CHM 556 Organic Chemistry II Degree 4 3 hr (Lecture) 3 hr (Practical) 3 Core CHM 456 Part Course Status Pre-requisite : : : Course Outcomes : Upon completion of this course‚ students should be able to: 1. Determine functional groups present in organic compounds using Infrared Spectroscopy and interpret Nuclear Magnetic Resonance spectra and relate the information to structural features of organic compounds. State and explain principles governing the physical
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Chemistry has been called the science of what things are. Its intent is the exploration of the nature of the materials that fabricate our physical environment‚ why they hold the different properties that depict them‚ how their atomic structure may be fathomed‚ and how they may be manipulated and changed. Although organic reactions have been conducted by man since the discovery of fire‚ the science of Organic chemistry did not develop until the turn of the eighteenth century‚ mainly in France at
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