[QUOTE = cajunbred ; 20103 ] Estoy tratando de convertir el siguiente para ppm mg / L.
( 1,667.4 ppm con una densidad de 1,0733 ) y ( 1.043.7 ppm con una densidad de 1,0975 ) . Estoy multipying la densidad de la ppm para lograr mis mg / L número ? ¿Cuál es la formulación correcta o mejor aún, la respuesta a los problemas antes mencionados ? Gracias ! [/ quote]
(1,667.4 ppm with a Density of 1.0733) and (1.043.7 ppm with a density of 1.0975 ). I am multipying the density by the ppm to achieve my mg/L number? What is the correct formulation or even better, the answer to the problems above? Thanks!
I'm not sure this ever got a satisfactory answer. Since someone painfully translated it into Spanish, maybe it is still current.
Read about the basic problem in posts 8 and 9. Ppm is ALWAYS ambiguous UNLESS it is qualified by the basis on which it was computed.
So there are either no answers or at least two answers to your question. Mrs X is probably 70% sure the 1667.4 ppm is on w/v basis and means 1667.4 mg/L. I am probably 70% sure it means 1667.4 mg/kg and needs to be multiplied by 1.0733 kg/L to yield 1789.6 mg/L.
But I wish to emphasize the point that neither of us can give an authoritative answer because the ppm is not qualified. By the time you add enough characters to qualify it (ppm w/w or ppm w/v), it takes more space than real units, mg/kg or mg/L.
However, people keep insisting on ppm, so best guesses by state of mixture are:
*Gases: Molar ratio (equivalent to partial pressures)
*Liquids: Either w/v or w/w, only the same for dilute water solutions. W/v is common in lab. chemistry, w/w is common in industrial scale chemistry. Also v/v is commonly used for liquid in liquid such as water/alcohol mixtures (alcohol by volume).
May I just correct the fundamentally wrong concept that ppm & mg/l are the same thing. They are not. The values can only be equivalent if the density of the two species being considered are the same.
For example; Consider 50 mg/l oil in Water. Oil Density of 780 kg/m3
50 mg of oil is 50 X 10^-6/780 = 64 x 10^-9 m3 = 64 x 10^-6 l
So you have 64 litres of oil / 1000000 litre of oily water, which is then 64ppm
This is a mistake that is rife even with experienced engineers.
ppm IS NOT same as mg/l unless the two species have identical densities
Ppm is actually ambiguous. It can be computed based on a ratio of weights, volumes, number of moles, or even weight/volume. Weight/weight is far more common than volume/volume (only percent alcohol by volume is commonly used). For any dilute solution in water, where density of the mixture is near 1 kg/L, ppm on w/w or w/v basis are the same. Oil in water would not typically be specified on v/v basis.