What is the volume of both hydrogen and oxygen?
354284
The volumne of a gas increases to fill its container and both H and O are gases at room temperature.  Is volume really what you want to know?
420597
Franpal is correct, hydrogen and oxygen.  If you're thinking of a D, it may be 'heavy water', which has Deuterium rather than hydrogen (an isotope of hydrogen).
809082
Water is a combination of 2 hydrogen atoms and 1 oxygen atom: H2O.\nnot H2O2!!!!!
928534
You are asked two questions and you need two answers:\n\n1) The chemical formula for water is H2O which shows that the two elements needed to combine are Hydrogen and Oxygen.\n\n2) The proportion of the two elements needed, is also shown by the formula. This is 2 /1 Hydrogen / Oxygen by volume, or 2 /16 by weight.
856297
V=55.0L\nP[H2 = 2.00 atm\nP[O2 = 3.00 atm\nT[1 = 25°C = 298 K\nT[2 = 125°C = 398 K\nR = 0.082057 L · atm / (K · mol)\n\nIdeal gas law: PV = nRT\n\nAt 25°C:\nsolving n for H2:\nn = PV/RT = 2.00 * 55 / (0.082057 * 298) mol = 4.498 mol\n\nsolving n for O2:\nn = PV/RT = 3.00 * 55 / (0.082057 * 298) mol = 6.748 mol\n\nAt 125°C:\nsolving n for H2:\nn = PV/RT = 2.00 * 55 / (0.082057 * 398) mol = 3.368 mol\n\nsolving n for O2:\nn = PV/RT = 3.00 * 55 / (0.082057 * 398) mol = 5.052 mol\n\nThe Reaction that occurs is:\nH2 + 1/2 O2 = H2O\n\nSo, hydrogen is the limiting reactant, leaving water and oxygen as the resulting composition.\n\nAt 25°C, 4.498 mol of H2 and 2.249 mol of O2 form 4.498 mol of H2O, leaving 4.499 mol of O2.  The total number of moles (n) is 8.997 mol\n\nAt 125°C, 3.368 mol of H2 and 1.644 mol of O2 form 3.368 mol of H2O, leaving 3.408 mol of O2.  The total number of moles (n) is 6.776 mol\n\nUsing the ideal gas law again:\nPV=nRT\n\nP = nRT/V\n\nAt 25°C:\nP = 8.997 mol * 0.082057 L · atm / (K · mol) * 298 K / 55 L = 4.00 atm\n\nAt 125°C:\nP = 6.776 mol * 0.082057 L · atm / (K · mol) * 398 K / 55L = 3.00 atm
972324
i juss know ....H + O2 = h20
212429
dots..\nits jux 2 hydrogen and 1 oxygen for every mole of h2o
945388
density,volume,weight,number of electron and proton.
756159
n   = pV/RT = 1.03*1.02/284*0.0821 = 0.045moles\n\nmoles of Nitrogen = 0.045*0.78=0.0351\n\nmoles of oxygen = 0.022*0.045 = 0.0098mole\n\nweight of the gases = 0.0098*32 + 0.0351*28.02 =0.316+ 0.986=1.3g\n\ndensity 1.3 g/l
982375
Hydrogen and oxygen, when combined in an appropriate mixture, will burn to form water.  By itself neither pure hydrogen nor pure oxygen will burn (they need an oxidizer and a reductant respectively).  Water is a stable chemical component that does not have the volatile characteristics of the elements that make up its composition (hydrogen and oxygen).
771136
NaC2H3O2 + H2O\n\nyou can't combine things unless they match with numerals. such as... you cannot add H3 and H because they are different chemicals/elements. if it were 3H + H you could combine them because its telling you that you have 3 hydrogens + and additional hydrogen. thus leaving you with NaC2H3O2 + whatever is left over. which would be an O and 2 H's. giving you the +H2O\n\nhope this helps!
903700
That is definitely not correct!!\n\nFor example water (H20) is very very different from the two gases that make it namely hydrogen (H2) and oxygen (O2)
744509
Each molecule of hydrogen contains 2 hydrogen atoms (H2) and each molecule of water contains 2 hydrogen atoms.  So a mole of water contains a mole of hydrogen.  For the second part of your question, there are 6.02e23 molecules of H2O in a mole of H2O.  Each H2O molecule contains 3 atoms, so a mole of H2O has 3*6.02e23 = 18.06e23 atoms.\n\nAdditional comment:  When one says "a mole of hydrogen," what is normally meant is a mole of hydrogen gas, which is H2, not a mole of hydrogen atoms.
291231
H2O...two parts hydrogen and 1 part oxygen in each of the water molecules.
587954
Measurements (In distance I'm assuming) would give you volume.\n\nMass / Volume = Density\n\nIf you have volume & density, you can rewrite the equation:\n\nMass = Volume * Density
149911
Density = Mass / Volume\nIf you know any 2 of the above quantities, you can find the other.
826844
H\n |    \nC=O:  (You need 2 lone pairs on Oxygen)\n |   \nH\n\nIt doesnt get much better than that :)