The solution was left undisturbed for 24 hours - Sample Essay
1) Alcohol solutions: ~ 30% ~70% 2) Hydrochloric acid: ~0. 005M ~0. 02M ~0. 08M Apparatus used: 1) Colorimeter 2) Beakers. 3) Graduated Cylinders. 4) Pipettes. 5) Droppers. 6) Test tubes. 7) Rubber stoppers. 8) Reagent bottles. 9) Test tube stand. 10) Glass rod. MATERIALS USED. Egg white. PREPARATION OF SOLUTIONS: 1) Alcohol: The concentration of the stock alcohol was 100% and hence needed to be diluted to the required concentrations that had to be used during the experiment. To prepare a 100 ml solution of 30% alcohol:
First I measured 70 ml of water using a measuring cylinder then I measured 30 ml of alcohol in another measuring cylinder. Then I poured the two solutions into a reagent bottle and stirred it with a glass rod. To prepare a 70% solution of alcohol: First I measured 30 ml of water in a measuring cylinder (care being taken to wash the measuring cylinder before use). Then I measured 70 ml of alcohol in a measuring cylinder. Then I poured the two solutions into a reagent bottle and stirred it with a glass rod. 2) Acid:
The concentration of the stock solution of hydrochloric acid in the laboratory was 1M solution this needed to be diluted to different concentrations that had to be used for the experiment. To dilute the acidic solution I used the equation: For the preparation of the acidic solution of concentration 01000/1 =1ml of acid For 50 ml of 0. 02M of acid I added = 49 ml of water +1 ml of acid I measured 49 ml of water using a measuring cylinder and poured it into a reagent bottle.
Then I measured 1 ml of the acid using a measuring cylinder. This also I poured into the reagent bottle. Then I stirred the two using a glass rod. For the preparation of the acidic solution of concentration 0. 08M: n= cV =0. 08*50/1000 =0. 004 moles n= cV =0. 004*1000/1 =4 ml For 50 ml of 0. 08M of acid I added= 4ml of acid and 46 ml of water. I measured 46 ml of water using a measuring cylinder and poured it into a reagent bottle. Then I measured 4 ml of the acid using a measuring cylinder. This also I poured into the reagent bottle. Then I stirred the two using a glass rod. EXPERIMENT.
The procedure used was the same for all solutions the only difference was that there were different solutions of different concentrations being used. For example the procedure used for 30% alcohol was: First I measured 5 ml of egg white (albumen) using a measuring cylinder. I poured the egg white into a test tube. Then I measured 10 ml of the test solution which is the 30% alcohol solution using a measuring cylinder. The test solution was poured into the test tube. The mouth of the test tube was covered with a rubber stopper to prevent any contamination and to prevent the other factors from affecting the egg white.
The solution was left undisturbed for 24 hours. This gave the alcohol enough time to act on the egg. After 24 hours the length of coagulant, was first measured with a ruler. The denaturation was measured using a device called the colorimeter. The colorimeter was left to warm up for about five minutes. Then the correct filter was obtained. This was done by placing the control and the different filters and the filters were changed until one filter gave the transmission through the control as zero.
This was the required filter; the filter number was 470/252. Then I poured the test solutions into the cuvettes and measured the percentage transmission of light, this gave the denaturation. SAFETY PRECAUTIONS WHILE WORKING WITH ACIDS AND ALCOHOL: Risk assessments: The first way was to separate myself physically from the chemicals and equipment by wearing protective equipment such as safety glasses, laboratory coats, and rubber gloves especially while working with hazardous chemicals such as acids and alcohol.
The second equally important way to protect myself from laboratory hazards was to be knowledgeable about the materials with which I was working and respectful of the danger they may present. Safety precautions: 1) The experiment involves handling glassware, which was breakable. I made sure to handle all glass with proper care, and making sure not to drop or knock over any pieces. 2) The experiment involved handling acid and base solutions, which can splash if, dropped. I made sure to handle all solutions with proper care, making sure to protect myself from spills.3) I made sure to wash all the apparatus thoroughly before and after use to prevent contamination when the apparatus are used again.