Investigating the Solubility of 5 Salts

1. PurposeThe experiments were carried out for measurement of solubility of 4 chosen coarsenesss in water to arrange these salts in the ascending order of solubility.2. IntroductionDifferent salts separate in water to different extent. This fact is of great importance in our daily life as well as in industrial human race like extraction of useful mineral/metal, purification of salts, corrosion etc. Solubility of salts is quantitatively expressed in different units. The most common creation maximum mass of a salt which can be completely dissolved in a unit mass of a solution hypothecate 14 gm of KNO3 per 100 gm of water i.e. of gm solute/gm solvent type. Other units ar Molarity (M), Molality (m), Normality (N), Mole section (X) etc. These different units are useful in different situations. It is easiest to experimentally pin down the solubility of a salt in gm (of salt)/100 gm (of solvent) unit and this value can easily be converted into other units by using suitable formulae . The formula to convert gm solute/gm solvent solubility value into molarity (M) is followingM = (1)Where, is density of solution in g/liter and formula mass is in g/mol.Materials are classified as insoluble, slightly soluble or soluble. Materials with solubility less than 0.01M are classified as insoluble.Experiments were carried out to measure solubility of four salts calcium Sulfate CaSO4, Copper (II) nitrate Cu(NO3)2, Potassium Nitrate KNO3 and Sodium Chloride NaCl.3. MaterialsApproximately five grams of to each one of salts Ammonium Nitrate NH4NO3, Calcium Sulfate CaSO4, Copper (II) Nitrate Cu(NO3)2, Potassium Nitrate KNO3 and Sodium Chloride NaCl, 250 ml beaker, 100 ml beaker, 50 ml burette and Parr DMA 35 density meter.4. Procedure4.1. Ammonium Nitrate NH4NO3 salt was ground into fine powders using a mortar and pestle.4.2. Approximately 5 gm of the salts was weighed using a balance and the exact mass was recorded for each of the salts.4.3. The salt powder was placed in a c lean 250 ml beaker.4.4. Water was added slowly using 50 ml burette and the solution was incessantly stirred while water was being added. Water addition was done until either all the salt powder was dissolved or 50 ml was reached, whichever occurred first.4.5. Volume of water required for complete detachment of the salt powder was recorded.4.6. minginess and temperature of the saturated salt solution was measured by using Parr Density meter and the same was recorded.4.7. Steps 4.1 through 4.6. were repeated for the remaining four salts and the values were recorded in a table.5. DataThe data from this experiment is presented in table 1 belowTable 1 Experimental data on solubility of the saltsSalt Mass of Salt (gm) Volume of H2O (ml) Temperature (oC) Density of settlement (gm/ml) CaSO4 5.088 50 none None Cu(NO3)2 5.020 23 30.4 1.125 KNO3 4.956 48 16.9 1.065 NaCl 4.993 49 20.2 1.0656. Results and AnalysisFrom data it is very clear that CaSO4 is insoluble in water.Solubility of remai ning three salts was deliberate using formula 1.For Cu(NO3)2M = 1.07 at 30.4 oC Hence solubleFor KNO3M = 1.00 at 16.9 oC Hence solubleFor NaClM = 1.20 at 20.2 oC Hence solubleThe results are presented in table 2 in the ascending order of solubility.Table 2 Solubility of given saltsSalt Solubility of Salt (g/100 g of water) Solubility of Salt (M) Temperature (oC) CaSO4 0 water-insoluble Not recorded KNO3 10.35 1.00 16.9 Cu(NO3)2 21.83 1.07 30.4 NaCl 10.20 1.20 20.2 The order of solubility of salts is followingCaSO4 KNO3 Cu(NO3)2 NaClThis order may get slightly modified if we compare solubility of salts at same temperature. It should be famed that solubility value depends on temperature and this is the reason, why solubility value is reported along with temperature.Glassware has been used in these experiments at visibility of solution was required to determine that salts were completely dissolved. Besides, these glass wares provide reasonable accuracy and are fairly less costly.The salts were ground into fine powder because fine powders accelerate rate of dissolution of salts, hence the experiment can be finished in short span of time.