Weight of Water per Gallon. The most widely accepted simple scientific answer to this question is that a gallon of room temperature water weighs 8.33 pounds. What’s more, if water is heated from room temperature, 70°F to its boiling point of 212°F, it will weigh 7.996 pounds, losing .333 pounds. [1].
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Given that a molecule of hydrogen weighs 1.01 Atomic Mass Unit (AMU) and one molecule of oxygen weighs 16 AMUs, the molecular weight of water is 18.02 AMUs.
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Actually, a pint of water weighs 1.04375 pounds. So, although this phrase does not provide the EXACT weight of each liquid, it does provide a very simple rule for determining approximately how much liquids weigh. In the case of water, there are eight (8) pints of water in a gallon.
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Temperature matters a bit. 8.34lbs 1 gallon of fresh water is about 8.36 According to the 21st edition of The Machinery's Handbook, 1 gallon of water weighs 8.337 pounds. To answer this question more appropriately you would have to know the temperature of the water.
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Using this rule, a gallon (eight pints) would weigh approximately eight (8) pounds, which is very, very close to a gallon of water's exact weight of 8.35 pounds which is found in the more detailed and scientifically correct answers to this question.
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Once you know the density, it is easy to figure out how much a gallon weighs (1 m3 = 264.17 gallons, and 1 kg = 2.2046 lbs, and 1 gallon = 3.7854 liters) Here are opinions and answers from FAQ Farmers: This depends on the amount of salt dissolved in the water.
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A gallon of water at room temperature weighs 8.33 pounds. The most widely accepted simple scientific answer to this question is that a gallon of room temperature water weighs 8.33 pounds.
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Baloo55th. 4 votes Vote for this answer. Ten pounds by the original definition for an imperial gallon of eight proper pints. The gallon was defined as the volume of distilled water weighing 10 lbs (with brass weights, of course) at 62 F (a comfortable temperature) and with the barometer at thirty inches. http://en.wikipedia.org/wiki/Imperial_units.
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So a Gallon of PURE common water weighs (at 68 degrees F) 8.32487 pounds. This includes the small amount of Heavy Water it will contain naturally. The water has to be Pure since if it is contaminated it will have a different weight depending on the makeup of the contaminates and how much contaminate there is.
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There are 8 pints in a gallon and a gallon weighs about 8 lbs. A pint is not exactly a pound but unless you are dealing with a lot of water it won't make much difference. As stated above a gallon (8 pints) weights 8 1/3 lbs. 3 gallons (24 pints) will weigh 25 pounds, 1 pound more than you would expect.
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how many pounds of water does a gallon weigh?
A gallon water weighs 8.33 pounds. There is 8.33 pounds of water in a gallon weigh.