Exercise 2. The Recrystallization of Potassium Nitrate

The tables of solubility show that at 20° about 32 g. of potassium nitrate dissolves in 100 g. of water while at 100° about 246 g. dissolves (Fig. 1). From a hot, saturated solution the salt deposits too rapidly to give good crystals, for the rate of radiation depends upon the difference between the temperature of the solution and that of the room. Modify the procedure of Exercise 1 as follows  

Additional Exercises Sodium nitrate, NaN03 lead nitrate, Pb(N03)2. 

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