If you live in a soft water area there will probably be no cloudiness. However, with tap water a cloudiness gradually develops if the water is from a hard water area since carbonates, sulphates or hydrogen carbonates may be present. The addition of deionised water to lead nitrate gives no cloudiness. The fact that lead forms insoluble compounds is used as a basis for indicating the presence of anions in water. The iodide is an intense yellow colour, the chromate(VI) is also yellow and both could be used as pigments except for the fact that lead compounds are toxic. The addition of solutions of each of the anions produces precipitates, which indicates that in general lead compounds are insoluble. Teaching notes and expected observations Part 1 What explanations can you give for your observations? What is the main disadvantage of using these compounds as pigments?.Which of the lead compounds observed appear to be good pigments?.Add one drop of deionised water and one drop of tap water to the appropriate boxes.With the worksheet still covered, put one drop of lead nitrate solution into each box of table 2.Part 2: adding deionised water and tap water to lead nitrate solution Add one drop of each of the solutions containing the anions indicated to the appropriate box.Put one drop of lead nitrate solution in each box of table 1.Cover the worksheet with a clear plastic sheet.Procedure Part 1: adding different anions to lead nitrate solution Potassium iodide, KI(aq), 0.2 mol dm –3 – see CLEAPSS Hazcard HC047b and CLEAPSS Recipe Book RB072.Sodium carbonate, 0.5 mol dm –3 – see CLEAPSS Hazcard HC095A and CLEAPSS Recipe Book RB080.
Sodium sulfate, Na 2SO 3 (aq), 0.5 mol dm –3 – see CLEAPSS Hazcard HC098B and CLEAPSS Recipe Book RB107.Potassium bromide, KBr(aq), 0.2 mol dm –3 – see CLEAPSS Hazcard HC047b and CLEAPSS Recipe Book RB068.The following chemicals are low hazard:.See CLEAPSS Hazcard HC078a and CLEAPSS Recipe Book RB069. Wear splash-proof eye-protection if transferring large amounts.
#Barium nitrate precipitate skin
and Shirokova, S.N., Analytical calculation of the density of mixed solutions, Preprint of the Bochvar All-Union Research Inst. Markowitz, M.M., Ricci, J.E., and Winternitz, P.F., J. Protsenko, P.I., Razumovskaya, O.N., and Brykova, N.A., Spravochnik po rastvorimosti nitritnykh i nitratnykh solevykh sistem (Handbook on the Solubility of Nitrite and Nitrate Salt Systems), Leningrad: Khimiya, 1971.įindlay, A., Morgan, I., and Morris, I., J. Mishina, N.E., Akhmatov, A.A., Zilberman, B.Ya., and Shadrin, A.Yu., Radiochemistry, 2010, vol. It was suggested that barium and strontium nitrates could form unstable adducts with HNO 3. The results of X-ray diffraction analysis are indicative of the formation of the precipitates with the structure similar to that of the dry salts, with simultaneously occurring changes in the texture of the precipitates formed from concentrated HNO 3. The IR spectra and structure of the double salt K 2Ba(NO 3) 4 were also examined they were found to differ from those of the components. The IR spectra of 0 to 23.5 M aqueous HNO 3 solutions were measured and compared to the spectra obtained by subtraction of the spectra of dry barium or strontium nitrate from the spectra of the wet crystals. The data of chemical analysis and IR spectroscopy suggest the presence of HNO 3 in the precipitates of barium and strontium nitrates and of their solid solutions, formed from concentrated nitric acid solutions. The chemical compositions of Ba(NO 3) 2 и Sr(NO 3) 2 precipitates obtained by precipitation from HNO 3 solutions of various concentrations were determined using an inert tracer.
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