Chemistry MCQs

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Magnetite, followed by Hematite – Limonite – Siderite

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The agricultural industry widely uses urea, a white crystalline solid containing 46 percent nitrogen as an animal feed additive and fertilizer. Urea has the highest nitrogen content of all solid fertilizers at 46% N.

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Silver is the metal with the highest electrical and thermal conductivity. It has only one valence electron, which can move around with little resistance. This makes silver a great conductor of electricity and heat.
Silver’s thermal conductivity is 430 wK/m, which is higher than copper (400 wK/m), aluminum (235 wK/m), and brass (109 wK/m).
Silver’s low contact wear resistance and excellent optical reflectivity make it ideal for coating contacts, mirrors, and conductors in telecom applications.
Impurities can decrease a conductor’s conductivity. For example, sterling silver is not as good of a conductor as pure silver. Oxidized silver is not as good a conductor as untarnished silver.

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Potassium permanganate is a point-of-entry treatment method that oxidizes dissolved iron, manganese, and hydrogen sulfide into solid particles that are filtered out of the water. It can also be used to control iron bacteria growth in wells.

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Sodium Alkyl Sulphate and Benzene Sulphate are typical examples of Synthetic Detergents. Synthetic detergents are man-made cleansing agents that function similarly to soap. These compounds were developed during World War II when a shortage of natural oils led to a search of alternative substances. The advanced features of synthetic detergents include improved cleansing efficacy, resistance to water hardness, and the ability to function in acidic conditions.

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Electronegativity is defined as an atom’s ability to attract an electron pair when forming a covalent bond. This property increases as you move left to right across the periodic table due to an increase in the nuclear charge’s attractive forces. It decreases as you move top to bottom, owing to the shielding effect of sub-levels and increased atomic radius, which makes electrons easier to remove. This culminates in Fluorine, being the highest and furthest to the right on the periodic table, hence it is the most electronegative.

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chemical oxygen demand is a measure of water quality and is amount of organic pollutants found in surface water. Potassium permanganate has been used for many years to measure COD

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Chlorargyrite is the mineral form of silver chloride (AgCl). It is also known as cerargyrite and, when weathered by desert air, as horn silver. Silver chloride is formed by the disappearance of the initial silver oxide layer.

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Ankylosing Spondylitis is a chronic, inflammatory arthritis and autoimmune disease that mainly affects joints in the spine and the sacroiliac joints in the pelvis. It tends to affect the spine and in late stages, the spine will fuse and this has given rise to the term “bamboo spine”. It is mainly caused due to impurities in drinking water associated with fluorides.

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Tear gas is also known as CS Gas. It acts as a lachrymatory agent. Tear gas irritate the mucous membrane of the eyes, nose, mouth and lungs, and causes tearing, coughing, burning and difficult breathing.