How to caculate the salinity of salt water?
The electrical conductivity of seawater is strongly dependent on its salinity. Thus oceanographers use a "CTD" instrument to measure Conductivity, Temperature and Depth. From conductivity, they can calculate seawater salinity. Before conductivity measurements were widely used, salinity was measured using chemical titration of the water sample with silver salts. To determine salinity u can use: http://www.es.flinders.edu.au/~mattom/Utilities/salcon.html This calculator determines salinity from measurements of in situ conductivity (from CTD measurements). or: http://www.es.flinders.edu.au/~mattom/Utilities/salinity.html where salinity is calculated from the conductivity ratio (measured by a salinometer). If you need formulas, go to http://oceanworld.tamu.edu/resources/ocng_textbook/chapter06/chapter06_01.htm there you can find not only formula of conductivity-salinity conversion, but also calculation of salinity based on chlorinity, and of the Practical Salinity Scale I hope, it would help
List several anions, by formula, that contribute to the salinity of a water sample ?
Salinity of normal water are attributed to some of the Anions of Cl-1 , Sulfate SO4-2 , Nitrates NO3-1 , Bicarbonates , HCO3-1 , Carbonates CO3-2 , and traces of Fluorides F-1 , Bromides Br-1 and found associated with cations of Sodium Na+1 , Ca +2, Mg+2 , K+1
List several anions, by formula, that contribute to the salinity of a water sample ?
The most common ones in natural waters are: Cl- SO4= CO3= Br- NO3- HCO3-
What are some cheap solutions for testing water quality?
Test strips are probably the cheapest way for a lot of water quality questions such as hardness, pH, and salinity. Microbes can really only be counted on a microscope, which is an expensive upfront cost for the microscope but cheap after that. Of course, if you are talking about drinking water, just boiling it, adding chlorine, and/or hitting it with UV light will knock out almost all bacteria/viruses worth mentioning. An observational test for solids is to put water on a plate and let it evaporate and see what is left behind on the plate. That said, most organic solids are not too harmful but there is no way of knowing what kind of solids you have just by looking at them. One way to measure organic content is to burn the solids really well and remeasure the weight of the solids since most of the organic material will burn off. Whatever is left is inorganic. There is no way to measure volitile organic compounds without expensive lab equipment, however these are not as important in developing areas as they have no acute toxicity, only long term exposure issues like cancer (sorry to sound callous, but its more important in developing countries not to die of dysentery before they need to worry about cancer). Metals are kind of the same as VOCs, except in cases where toxic metals are extremely high, usually in near industrial wastelands.If you are concerned about water treatment, simple solutions like sand filters, 5 micron fiber filters, chlorine tablets, and UV 254 light will be sufficient to treat 99% of water quality scenarios. And you really don't have to test all that much because most of it will be removed regardless. Of course, you can get much more complicated if you like but this is just basic stay alive type of water treatment.
Qualitative Analysis of Ionic Compounds?
1) The solution is treated with silver nitrate solution. Awhite precipitate forms. List all anions that could bepresent. my answer: F, Cl, Br, or I but AgBr is cream and AgI yellow! What about Ag2CO3? You normally add nitric acid in a silver nitrate test to destroy this. 2) Addition of nitric acid to another sample of the SAMEsolution prodcued a colorless, odorless gas. On the basis of thistest, what anions are present? Possibly a carbonate? 3) When another sample of the SAME solution was treated withmagnesium chloride, there was a white precipitate. What singleanion is present? CO3 2-
How is the concentration of salt measured in saltwater?
In the field, salinity is usually measured by comparing conductivity to pH. The more conductive the water at a given pH, the higher the concentration of salt. This is fairly accurate.One can also use a hydrometer. The denser the water, the higher salinity. This is also fairly accurate.Finally, weighing a sample in a borosilicate beaker and then boiling off the water and weighing again will get you a close approximation to the salt concentration.None of these really account for non-salts that affect the individual method’s accuracy. If you require that much accuracy, though, you might as well send the sample off for analysis.
How do you test for sulphate ions in water?
When Barium chloride(BaCl2) is added to water solution of sulphate ions, Barium sulphate(BaSO4) is formed. Barium sulphate is insoluble in water and will be seen as white ppts.O.S. + BaCl2 ---> BaSO4 (White ppts)To identify between sulphate(SO4) and sulphite(SO3), add Barium chloride and HNO3 with few drops of malachite green solution, if green colour of malachite green disappear then it is sulphite or it is sulphate.
Why doesn't NaCl contribute to the hardness of water?
Hardness in water is caused by the presence of multivalent cations in the water in the form of dissolved salts. Multivalent cations, meaning cations that have oxidation state greater than +1.As you can see, Sodium (Na+) is incapable of making multivalent cations while Magnesium (Mg2+) and Calcium (Ca2+) exist as multivalent cations.Now, why does it have to be multivalent cations? Simple, because multivalent cations have the ability to form bonds on two or more sides.You asked why NaCl (and presumably other Sodium salts) don't feature into the calculation of water hardness. Consider this. The most common problem created by water hardness is that it reacts with soap and turns it into a precipitate like mass. Guess what, soap generally contains Sodium and Potassium ions.The micelle structure of soap that is responsible for cleaning contains a hydrophobic end (which is basically an organic substrate, nonpolar in nature) and a hydrophilic end which is generally the carboxylate group attached to the Na+ or K+ ion (polar end). The working of soap, thus, follows this pattern. The hydrophobic ends of several soap molecules attach themselves to the oily, fatty impurities (which we are trying to clean) and the hydrophilic ends point outwards. In the end, the oil/fat based impurity gets stuck in a hydrophobic cage which has a hydrophilic exterior. Then we rinse with water, and this hydrophilic exterior gets attracted to water (thus the name hydrophilic). The hydrophobic end and the trapped impurity, being a part of the structure, get carried away along with this. Result, cleanliness.Now bring Calcium and Magnesium salts into the picture. Being Alkaline earth metals, they are less reactive than Sodium or Potassium which are Alkali metals. Consequently, Sodium and Potassium ions from the soap will quickly replace them as soon as our soap contacts this hard water. The poor Calcium/Magnesium ions that are left behind have no choice but to now attach with the carboxylate side of the fatty nonpolar substrate of the soap. And since these elements are divalent, one Calcium/Magnesium ion connects with two fatty substrates. Result, a substance that has two hydrophobic ends and zero hydrophilic ends.Voila, our ever so carefully engineered soap structure is now a useless fatty complex that cannot even stay dissolved in water anymore.I hope this explanation cleared your doubt! Have a nice day!
How can you test a solution for H+ anions and H- cations?
There are many manufacturers of pH meters that will measure the concentration of H+ cations. H- anions would not exist in water solutions, reacting with it to form H2 gas and OH- anions, which could lead to the answer you seek by measuring the resulting pOH (14 - pH) or measuring the volume of H2 gas generated.