Effect of Temperature on Solubility of Potassium Chloride in Water

Next, I poured distilled water just below the 250ml mark on the neck of the volumetric flask.

30. Same as carried out in Part (b), repeat steps 18. to 24. to dissolve the gas in the syringe in the heated de-ionised water.

The objective of this extraction experiment was to achieve a comprehensive understanding, as well as master the practice, of the technique of separating various individual components of a compound.

The objective of this lab was first to convert the mass of a compound to the number of moles and number of molecules and then determine the concentration of salt and its component. The first thing we did was get the mass of an empty container by using a scale and it came out to be 16.87g. Next thing we did was pick a substance which in this case it was Potassium Chloride and placed it on the scale to get a total mass of 31.20g. The container the Potassium Chloride was in only had a mass of 16.87g which means that the mass of the substance was 14.33g. To convert the mass to the number of moles we took the amount of the substance 14.33g and divided it by the mass of Potassium Chloride 74.55g and figured out that the number of moles was 0.192.

If you dissolve a substance such as ordinary table salt (NaCl) in water, the boiling point of the water will increase relative to the boiling point of the pure water. In this assignment, you will dissolve a sample of NaCl in water and then measure the boiling point elevation for the solution.

In the third stage of this experiment, the density of a liquid was determined and compared to known standards. A 100ml beaker was filled to about half-full with room-temperature distilled water. The temperature of the water in ◦C was recorded in order to compare to known standards later. A 50ml beaker was then weighed on a scale in order to determine mass and recorded. A sample of the distilled water with an exact volume of 10ml was then placed in the 50ml beaker using a volumetric pipette. The 50ml beaker with the 10ml of water was then weighed again and the initial mass of the beaker was subtracted from this mass to obtain the mass of the 10ml of water. With the volume and the mass of the water now known, density was calculated using d = m/V and recorded in g/ml. This process was then repeated to check for precision and compared to standard values to check for accuracy. Standard values were obtained from CRC Handbook, 88th Ed.

The correct syringe is used to place 10 cm3 of the first glucose solution into the boiling tube.

When filling up the burette it is important that a funnel is used, however as the solution reaches the 0 mark it is ideal that the funnel be removed and a pipette used instead to reach the 0 mark, this is to achieve greater precision. During the experiment, it is important to swirl the flask continuously with one hand

The volume of a small test tube and a thin-stemmed pipet were determined in this section of the lab. Water was poured into a small test tube until the water reached the very top edge of the test tube. The test tube was then emptied into a plastic 25 mL graduated cylinder and volume was measured and recorded into data table 3. A think-stemmed pipet was completely filled with water. Drops were carefully counted and emptied into the empty plastic 25 mL graduated cylinder until the water level reached 1 mL. The number of drops in 1 mL was recorded into data table 3. The thin-stemmed pipet had a total volume of 4 mL and that was also recorded into data table 3.

Using the direct weighing and weighing by difference methods to find weight and mass of chemicals and compounds.

Intermolecular forces hold molecules together when they are in solid or liquid state. However, water has the ability to dissociate many salts and ionic compounds. This is called dissolving. When NaCl is added to water, it dissociates into the ions; Na+ and Cl- . The positive sodium ions are surrounded by the slightly negatively charged part of water molecules (i.e. oxygen) in the water molecules and the negative chlorine ions are surrounded by the slightly positively charged part of water molecules (i.e. the hydrogen). The kinetic energy of the sodium chloride molecules increase with temperature. This destabilizes the solid state that it is currently in. This increased motion means that the molecules are less able to hold together and as such they dissolve at faster rates and larger amounts.

The start of the experiment consisted of filling up four beakers with de-ionized water to 150 ml. After the beakers were filled to the appropriate amounts they were then labeled with the

a) Transfer pipette was obtained. The pipette was cleaned because distilled water does not drain uniformly. A cleaning solution or detergent was used to clean the pipette.

12.Syringe, to measure out volumes of water, this will be used as it provides a more accurate measurement than a beaker.

Extraction vessels: Jars or bottles with sufficient capacity to hold the sample and extraction fluid. Two liter normal capacity bottles are recommended. The vessel type is determined by the analysis of interest.