If you mean hydrogen gas, H2, just naturally present in the water, then essentially none.
If you mean how much hydrogen gas could be generated by the electrolysis of 1 gallon of water, that is a stoichiometry problem. The balanced reaction is:
2H2O --> 2H2 + O2
The mass of 1 gallon of water is 3.7854 kilograms, which is 210.3 moles of H2O. From the stoichiometry, there is a 1 to 1 (2 to 2) ratio of water to hydrogen produced, and so 210.3 moles of H2 will be produced. 210.3 moles of H2 weighs 420.6 grams, or just under one pound (see the Related Questions links to find out how to calculate the volume of that much H2 produced).
If you mean hydrogen ions, H+, then it depends on the pH of the water. In perfectly pure, neutral water with pH of 7, then the concentration of H+ is 10-7 moles per liter. In one gallon, there are 3.7854 liters. So in one gallon of pure water, there are 3.7854 * 10-7 moles of H+.
See the Related Questions for more information about pH and how it measures the concentration of H+.
A kilogallon would be 1000 gallons. It is not commonly used however
1000
100
== Probably close to the weight of water. 8.34 lbs per gallon.
13.5 lbs. per Imperial Gallon / 11.86 lbs per US Gallon.
Use one gallon of chlorine for every 10,000 gallons of water.
This combination produces water.Water molecules are consist of a hydrogen ion and a hydroxide ion. One hydrogen ion and one hydroxide ion combines to make a water mlecule.
H2O = Hydrogen two oxygen, (two hydrogen atoms and one oxygen atom = one water molecule) which is the chemical formula for water.
The chemical formula for water is H2O. In one gallon of water, there are 210 moles. This means that breaking apart the water will release 420 moles of hydrogen gas. This is equivalent to 4710 liters of gas.
About 8.35 pounds for one US gallon of water.
Burning 1 gallon of gasoline produces 1.52 gallons of water. How this is calculated:1 gallon of gasoline weights 8.66lbs, of which 1.4 lbs is Hydrogen, as gasoline contains 16% Hydrogen and 84% carbon by weight.This assumes gasoline has the chemical formula of C8H18, the same as Octane.Water is 11% Hydrogen and 89% Oxygen by weight. One gallon of water weights 8.35lbs, and contains .92 lbs of Hydrogen, and 7.43 lbs of oxygen.Therefore since hydrogen burned or in, equals hydrogen out after combustion, therefore 1.4 lbs of hydrogen burned, equals 1.4 lbs of hydrogen in the H20 or water created in combustion. By weight, 1.4 lbs of hydrogen divided by the weight of .92 lbs of hydrogen in water, equals 1.52. So 1.4 lbs of hydrogen in 1 gallon of gasoline, is converted to more gallons of water because gasoline contains more hydrogen per gallon, then does water.
None. Pure water has only hydrogen and oxygen.
At 17oC one gallon of water weighs 4.536kg.
1 gallon of fresh water is about 8.36 pounds
one tenth of a gallon
One gallon of water weighs about 8.35 pounds (about 3.8 kilograms).
1/2 gallon ideally
One gallon of water
One.
1 quart of water is 1/4 as much as 1 gallon of water.