In this experiment, the behaviour of water during boiling process is observed. When water is heated to boiling temperature at constant volume, different regimes are observed until it reaches to saturation pressure. If the pressure is above 1.013 bar, the water is supersaturated. The pressure at which boiling occurs is known as saturation pressure. The standard conditions at which water boiling take place are 100C and 1.013 bar.
The miscibility of ionic liquids with water or organic solvents varies with side chain lengths on the cation and with choice of anion. They can be functionalized to act as acids, bases or ligands, and have been used as precursor salts in the preparation of stable carbenes. Because of their distinctive properties, ionic liquids are attracting increasing attention in many fields, including organic chemistry, electrochemistry, catalysis, physical chemistry, and engineering; see for instance magnetic ionic
For this purpose 0.1N HCl, pH 4.6 buffer, pH 6.8 buffer and purified water were used. Highest dose of the drug i.e., 400mg was dissolved in 250 mL of medium and was kept untouched for 6 hrs. Later on the insoluble drug was filtered off and the solution was analysed by HPLC technique to find out the solubility. Based on the solubility calculated the D/S ratios were calculated. The FDA guidance on “Dissolution Testing of Immediate Release Solid Oral Dosage Forms” says that a drug substance is considered highly soluble when the dose/solubility volume of solution are less than or equal to 250 mL.
2.3 SOLUBILITY 2.3.1 Introduction  Drug solubility is the greatest concentration of the drug dissolved in the solvent under specific condition of temperature, pH and pressure. As solubility is an important determinant in drug liberation hence it plays a key function in its bioavailability. For absorption of any drug it must be present in the form of an aqueous solution at the site of absorption. About 40% of all new chemical entities have poor bioavailability. The bioavailability can be increased by changes in disintegration and dissolution.
THEORY OF THE EXPERIMENT In this experiment change in the volume of reagents by diluting with water is used as change in the concentration and reciprocal of the time taken for the appearance of blue black colour as the reaction rate. Equation of reaction H2O2 (aq) + 2H+ (aq) +2I- (aq) I2 + 2H2O Hypothesis Hypothesis 1: Decrease in concentration of hydrogen peroxide (H2O2) decreases the rate of reaction (that is, increases the time for reaction to come to completion). In the reaction between potassium iodide (KI), hydrogen peroxide, Sodium thiosulfate (Na2S2O4) under acidic condition. Hypothesis 2: Decrease in the concentration of potassium iodide decreases the rate of reaction (that is increases the time for the reaction to come to completion). In the reaction between potassium iodide (KI), hydrogen peroxide, sodium thiosulfate (Na2S2O3) under acidic condition.
Not only does it allow molecules to enter cells, but also removes waste products. Osmosis is the diffusion of water. This means that osmosis refers specifically to the movement of water across a semi-permeable membrane down a water concentration gradient. Therefore, completing this experiment will allow us to come to a conclusion as to how much a solute concentration gradient affects osmosis across semi-permeable membranes, and how we can apply what we have learnt to the world surrounding us. Relation to Semi-Permeable Membranes within the Context of our Experiment: In this experiment, we will explore the specific movement of
Crystallization is attained by a three step process, first supersaturation state, second nucleation and third growth of crystals. For solute to leave the solution a certain degree of supersaturation is necessary, where the solvent will contain excess of solute that it can contain at a particular temperature , . Some of the methods that induce supersaturation are methods based on change in temperature, solvent removal, drowning out and reaction partners . Crystallization of APIs has been studied using various methods though cooling crystallization  and anti-solvent crystallization  have been most common. Even though cooling crystallization and anti-solvent crystallization are convenient, it has major drawbacks in terms of slow rate of crystallization, high supersaturation degree , solvent and anti-solvent selection based on solubility.
Each solute has its own equilibrium between adsorption onto the surface of the solid (stationary phase) and solubility in the solvent (mobile phase). Based on the nature, polar compounds adsorb with stronger or greater affinity to the polar
The melting point of substance depends on pressure and is usually specified at standard pressure. But when temperature is reverse changes from liquid to solid, it is referred to as the freezing point or crystallization point.4 1.9.2. pH - pH is a measure of the acidity or alkalinity of a water solution. The acidity or alkalinity of a water solution is determined by the relative number of hydrogen ions (H+) or hydroxyl ions (OH-) present. Acidic solutions have a higher relative number of hydrogen ions, while alkaline (also called basic) solutions have a higher relative number of hydroxyl ions. Acids are substances which either dissociates (split apart) to release hydrogen ions or react with water to form hydrogen ions.
Some least soluble compounds are oxidized and are changed into water, carbondioxide and compounds that are soluble in water for their quick removal. The cleaning capacity is low for some compounds as a result they will be present in air for a longer time.However air pollution and change in climate condition are directly related.Increase in levels of the green house gases alter the balance of energy among the atmosphere and surface