Search results
Results from the WOW.Com Content Network
For hydrocarbons, the DBE (or IHD) tells us the number of rings and/or extra bonds in a non-saturated structure, which equals the number of hydrogen pairs that are required to make the structure saturated, simply because joining two elements to form a ring or adding one extra bond (e.g., a single bond changed to a double bond) in a structure reduces the need for two H's.
It is necessary to calculate the mass of a solid acid which will react with about 20 cm 3 of this solution (for a titration using a 25 cm 3 burette): suitable solid acids include oxalic acid dihydrate, potassium hydrogen phthalate and potassium hydrogen iodate. The equivalent weights of the three acids 63.04 g, 204.23 g and 389.92 g ...
An equivalent (symbol: officially equiv; [1] unofficially but often Eq [2]) is the amount of a substance that reacts with (or is equivalent to) an arbitrary amount (typically one mole) of another substance in a given chemical reaction. It is an archaic quantity that was used in chemistry and the biological sciences (see Equivalent weight § In ...
Hydrogen at atmospheric pressure has an energy density of 120 MJ/kg (113,738 BTU/kg), [122] by converting this energy density to a GGE, it is found that 1.011 kg of hydrogen is needed to meet the equivalent energy of one gallon of gasoline. This conversion factor can now be used to calculate the MPGe for this vehicle.
The amine value is useful in helping determine the correct stoichiometry of a two component amine cure epoxy resin system. [6] [7] [8]It is the number of Nitrogens x 56.1 (Mwt of KOH) x 1000 (convert to milligrams) divided by molecular mass of the amine functional compound.
Data from same reference as for liquid hydrogen. [21] High-pressure tanks weigh much more than the hydrogen they can hold. The hydrogen may be around 5.7% of the total mass, [22] giving just 6.8 MJ per kg total mass for the LHV. See note above about use in fuel cells. Hydrogen, gas (1 atm or 101.3 kPa, 25 °C) 141.86 (HHV) 119.93 (LHV) 0.011 88 ...
Multiplying by the molar mass constant ensures that the calculation is dimensionally correct: standard relative atomic masses are dimensionless quantities (i.e., pure numbers) whereas molar masses have units (in this case, grams per mole). Some elements are usually encountered as molecules, e.g. hydrogen (H 2), sulfur (S 8), chlorine (Cl 2 ...
Hydrogen is a chemical element; it has symbol H and atomic number 1. It is the lightest element and, at standard conditions, is a gas of diatomic molecules with the formula H 2, sometimes called dihydrogen, [11] but more commonly called hydrogen gas, molecular hydrogen or simply hydrogen.