Search results
Results from the WOW.Com Content Network
Sodium carbonate (also known as washing soda, soda ash and soda crystals) is the inorganic compound with the formula Na 2 CO 3 and its various hydrates.All forms are white, odourless, water-soluble salts that yield alkaline solutions in water.
Sodium percarbonate or sodium carbonate peroxide is a chemical substance with empirical formula Na 2 H 3 CO 6.It is an adduct of sodium carbonate ("soda ash" or "washing soda") and hydrogen peroxide (that is, a perhydrate) whose formula is more properly written as 2 Na 2 CO 3 · 3 H 2 O 2.
Approximate definition of a mole based on 12 grams of carbon-12. The Avogadro constant was historically derived from the old definition of the mole as the amount of substance in 12 grams of carbon-12 (12 C); or, equivalently, the number of daltons in a gram, where the dalton is defined as 1 / 12 of the mass of a 12 C atom. [9]
Molecular weight (M.W.) (for molecular compounds) and formula weight (F.W.) (for non-molecular compounds), are older terms for what is now more correctly called the relative molar mass (M r). [8] This is a dimensionless quantity (i.e., a pure number, without units) equal to the molar mass divided by the molar mass constant .
The relationship between the two constants is R s = R / m, where m is the molecular mass of the gas. The US Standard Atmosphere (USSA) uses 8.31432 m 3 ·Pa/(mol·K) as the value of R. However, the USSA in 1976 does recognize that this value is not consistent with the values of the Avogadro constant and the Boltzmann constant. [49]
The terms "molecular mass", "molecular weight", and "molar mass" may be used interchangeably in less formal contexts where unit- and quantity-correctness is not needed. The molecular mass is more commonly used when referring to the mass of a single or specific well-defined molecule and less commonly than molecular weight when referring to a ...
[12] The prefix bi- in "bicarbonate" comes from an outdated naming system predating molecular knowledge. It is based on the observation that there is twice as much carbonate (CO 3 −2 ) per sodium in sodium bicarbonate (NaHCO 3 ) as there is in sodium carbonate (Na 2 CO 3 ). [ 13 ]
0.1 × ( 12 ÷ 8 ) = 0.15 grain per dscf when corrected to a gas having a specified reference CO 2 content of 12 volume %. Notes: Although ppmv and grains per dscf have been used in the above examples, concentrations such as ppbv (i.e., parts per billion by volume), volume percent, grams per dscm and many others may also be used.