he solubility studies were done for pure KDP and KDP doped with small amount (5 M%) of K2CO3 as additive. Solubility studies were carried out in a constant- temperature water bath with cryostat facility with an accuracy of 70.011C. Stirring was done using an immersible magnetic stirrer. The solution was stirred continuously for 6 h to achieve stabilization. Solubility was determined by gravimetric analysis for different temperatures (30–50 1C). The solubility curve of pure KDP is shown in Fig. 1.