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hard water
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Quizzes
water glass on white background. (drink; clear; clean water; liquid)
Water and its Varying Forms
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Iceberg, Arctic (polar, environment, global warming)
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A Factory Interior, watercolor, pen and gray ink, graphite, and white goache on wove paper by unknown artist, c. 1871-91; in the Yale Center for British Art. Industrial Revolution England
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Solar Eclipse, Eclipse, Solar Flare, Outer Space, Astronomy
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Albert Einstein in Washington, D.C. c. 1921-1923. Physicist
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Artist interpretation of a Space meteoroid impact. Meteor impact. Asteroid, End of the world, danger, destruction, dinosaur extinct, Judgement Day, Planet Earth, Doomsday Predictions, comet
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Science & Tech

hard water

chemistry
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Category: Science & Tech
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hard water, water that contains salts of calcium and magnesium principally as bicarbonates, chlorides, and sulfates. Ferrous iron may also be present; oxidized to the ferric form, it appears as a reddish brown stain on washed fabrics and enameled surfaces. Water hardness that is caused by calcium bicarbonate is known as temporary, because boiling converts the bicarbonate to the insoluble carbonate; hardness from the other salts is called permanent. Calcium and magnesium ions in hard water react with the higher fatty acids of soap to form an insoluble gelatinous curd, thereby causing a waste of the soap. This objectionable reaction ...(100 of 269 words)

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