1 HIGHER SECONDARY MODEL EXAMINATION HSE II Max.marks: 60 CHEMISTRY Time: 2.45 hrs General instructions All questions are compulsory Cool-off time is 15 minutes 1] Defects modify the properties of crystals [4 marks] A] Give differences between Schottky and Frenkel defects [2.0] B] On heating zinc oxide becomes yellow in colour. Why? [1.0 ] C] Alkali metal halides on heating in presence of alkali metal produce characteristic colours.Give reason [1.0] 2] Colligative
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PERFUME Perfume is a mixture of fragrant essential oils and aroma compounds‚ fixatives‚ and solvents used to give the human body‚ animals‚ objects‚ and living spaces a pleasant scent The Fragrance wheel is a relatively new classification method that is widely used in retail and in the fragrance industry. The method was created in 1983 by Michael Edwards‚ a consultant in the perfume industry‚ who designed his own scheme of fragrance classification.The new scheme was created in order to simplify
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Guava is a small tropical tree that grows up to 35 feet tall; it is widely grown for its fruit in tropics. It is a member of the Myrtaceae family‚ with about 133 genera and more than 3‚800 species. The leaves and bark of P. guajava tree have a long history of medicinal uses that are still employed today (Nwinyi et al.‚ 2008). In the view of the immense medicinal importance of P. guajava plant evidenced in the various studies mentioned above and also corroborated in a recent review article by Kamath
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organism resulted in a purple medium resulting in a positive test. The indole production test is tested after incubation of the tube. To get the results‚ Kovac’s reagent must be added to the tube. Kovac’s reagent has the indicator p-dimethylamino-benzaldehyde which will produce a red ring on the surface of the agar resulting in a positive test. After incubation‚ I added Kovac’s reagent into the MIO tube which did not result in a color change‚ indicating a negative result for indole
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What is the Difference between Flammable and Combustible Liquids? Put simply‚ flammable and combustible liquids are liquids that can burn. The real difference lies within their flash point range‚ or lowest temperature at which vapours of the material will ignite when supplied with an ignition source. Flammable and combustible liquids are utilised in most workplaces‚ from manufacturing to retail and service entities. To ensure the safety of property‚ people‚ and the environment‚ both flammable
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Chemistry GENERAL CHEMISTRY: Atomic Structure and elementary quantum mechanics: Blackbody radiation‚ Planck’s radiation law‚ photoelectric effect‚ Compton Effect‚ de Broglie’s hypothesis‚ Heisenberg’s uncertainty principle. Postulates of quantum mechanics‚ Schrodinger wave equation and a particle in a box‚ energy levels‚ wave functions and probability densities‚ Schrodinger wave equation for H-atom‚ Separation of variables‚ Radial and angular functions‚ hydrogen like wave functions‚ quantum numbers
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characterized by redness‚ watering‚ and itching. Potential Chronic Health Effects: Very hazardous in case of eye contact (irritant). Hazardous in case of skin contact (irritant). Slightly hazardous in case of ingestion‚ of inhalation Benzaldehyde Flammability of the Product: Combustible. Auto-Ignition Temperature: 192°C (377.6°F) Flash Points: CLOSED CUP: 64.4°C (147.9°F). OPEN CUP: 73.9°C (165°F). Flammable Limits: LOWER: 1.4% Products of Combustion: These products are carbon
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Notes Aldehydes and Ketones The major similarity between an aldehyde and a ketone is the carbonyl group. A carbonyl group is a carbon atom doubly bonded to an oxygen atom. [pic] Both molecules have a carbonyl group‚ the difference the number of carbons bonded to the carbonyl carbon. An aldehyde will have none or one and a ketone will have two carbons. All aldehydes‚ except formaldehyde‚ will have a hydrogen atom on one side of the carbonyl carbon and at least on carbon on the other side
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1. (a)Correct the following statements. (i) The melting points of crystalline and amorphous solids are not definite. The melting point of an amorphous solid is not definite. OR The melting point of a crystalline solid is definite. P Ps X solute . Ps P Ps The equation for relative lowering of vapour pressure when solute remains normal is X solute P (iii)The degree of ionization decreases with dilution. The degree of ionisation increases with dilution. (iv) Tertiary butyl halide
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The Love Canal Tragedy— a historical event which had an immense impact on the lives of those involved‚ as well as the laws and regulations set by the Environmental Protection Agency (EPA). It began as a plan by entrepreneur William T. Love to construct a canal that could act as a water source and conduct power using hydroelectricity‚ but rather served as a connector between Lake Ontario and the Niagara River. While his proposal sounded as though it would be a success‚ all construction came to a halt
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