1) To learn the qualitative and quantitative aspects of common laboratory equipment.
2) To expose to the factors that affect the accuracy of an experiment.
Chemistry is an experimental science. This experiment was introduced to the student about the basic laboratory technique that commonly used when had an experiment in the lab. It is the basic method for the newbie student to mastery of the techniques, concepts, and calculations. This knowledge should be use to avoid form make mistakes and errors during an experiment. The key techniques when doing analysis for any experiment must be done wisely balancing accuracy.
Volumetric flasks are used for precise dilutions and preparation of standard solutions.
4743450571500A pipette or chemical dropper is a laboratory tool commonly used to transport measured volume of liquid.
446722514033500 C) Burette
It is used to dispense known amounts of a liquid reagent in experiments for which precision is necessary, such as a titration experiment.
1) Analytical balance 6) Thermometer 1) Distilled water
2) Burette 7) Pipette filler
3) Pipette (20mL) 8) Retort stand
4) Volumetric flask (25mL) 9) Burette clamp
5) Beaker 10) Dropper
A. CALIBRATION OF VOLUMETRIC FLASK
1. A 25 mL volumetric flask was cleaned and dried. The volume flask was weighed accurately using analytical balance. The mass of empty volumetric flask was recorded.
2. Distilled water was added until the calibration mark (dropper was used to add the last few drops of distilled water) and was weighed again by using the same analytical balance. The mass of distilled water and volumetric flask was recorded.
3. The temperature of the distilled water was recorded.
4. The actual volume of the volumetric flask was determined from the table 1.
B. CALIBRRATION OF PIPETTE
1. A 50ml beaker was cleaned and dried. The beaker was weighed accurately by using analytical balance. The mass of empty beaker was recorded.
2. A 20ml pipette was cleaned and rinsed with distilled water.
3. The pipette was filled by the distilled water by using the procedures that have been discussed in the introduction part.
4. The Distilled water was drained into the beaker and weighed again. The mass of distilled water and beaker was recorded.
5. Step 1-4 was repeated one more time and temperature of distilled water was recorded.
6. The actual volume of the pipette is determined from table 1.
C) CALIBRATION OF BURETTE
1) A 50 mL beaker was cleaned and dried .The beaker was weighed accurately using analytical balance. The mass of empty beaker was recorded.
2) The burette was cleaned and rinsed by using distilled water and the burette was filled with distilled water until the zero mark.(make sure there is no bubbles in the tip of burette).
3) 5 mL of water from the burette was drained into the beaker and weighed as soon as possible. The mass was recorded.
4) Step 3 was repeated by draining water from the burette until the following burette reading become 10 mL,15 mL and 20mL.(5mL of distilled water had been added from the burette each time).The mass (distilled water + beaker) every time after adding 5mL of water was recorded.
5) The temperature of distilled water was recorded.
6) The actual volume for every addition of 5 mL of distilled water was determined from table 1.
Name : MOHAMED FAZRIN BIN MOHAMED ZAMRI Date : 13/9/2018
Student ID : 2018232098 Group : EC1101B
A) Calibration of volumetric flask
Mass of empty volumetric flask(g) 26.40
Mass of volumetric flask + distilled water(g) 51.25
Mass of distilled water (g) 24.85
Temperature of distilled water ( oC) 31
Density of water (from Table 1) (g/mL) 1.0053
B) Calibration of Pipette
Mass of empty beaker(g) 34.74 34.69
Mass of beaker + distilled water(g) 56.01 55.79
Mass of distilled water (g) 21.27 21.10
Temperature of distilled water (o C )30.5 31
Density of water(from Table 1)(g/mL) 1.0053 1.0053
C) Calibration of burette
Mass of empty beaker (g) : 34.56 g
Temperature of distilled water (o C) : 31 o C
Density of water ( from Table 1 ) (g/mL) : 1.0053
After the addition of distilled water :Reading of burette (mL) Mass of beaker + distilled water(g) Mass of distilled water(g) Mass of distilled water for each 5 mL burette reading (g)
5 39.68 5.12 5.12
10 44.52 9.96 4.78
15 49.30 14.74 4.78
20 54.10 19.54 4.80
a) Determine the actual volume of the volumetric flask based on calculation.
b) Determine the actual volume of the pipette based on the calculation for experiment (i) and (ii).
c) Determine the actual volume of distilled water in ml for each of 5 ml burette reading based on calculation.
Reading of burette (ml) Volume of water (ml)
The results that was obtained in this experiment were closely from what the theory said. The volume for the volumetric flask had a bit different which the volume that have been calculated was 24.72 mL while the theory was supposed to be 25mL. The volume for the pipette also does not accurate which the calculated volume for the first try was 21.16 mL and the second try was 24.72 mL when the theory volume was 25mL.For the first time the burette volume removed was 5mL but the calculated volume that have been removed was 5.10mL.Then,for the second time and others, the volume that have been removed was less than 5mL. This may be caused by parallax error which the position of the eyes was not perpendicular to the scale while reading burette scale. Not only that, the result may be affected because of the volume of distilled water which may be under or over the meniscus level.
At the end of the experiment basic laboratory apparatus to measure the mass, volume, temperature and density had been learned. In doing this experiment, the observation and calculation is important to get a good result. The accurate results will appeared when follow step by step wisely.
Answer of the questions:
1) How do you overcome or reduce the problem of random error and systematic error while doing an experiment?
To overcome or reduce the problem of random error and systematic error while doing an experiment is by repeating the experiment against and use different techniques or equipment.
2) In what situation do you use a volumetric flask, conical flask, pipette and graduated cylinder? Explain your answer from the accuracy aspects of these apparatus.
Volumetric flasks are used for precise dilutions and preparation of standard solutions. Conical flask used in titration and suitable for boiling liquids. Pipette are commonly used to transport measured volume of liquid. The graduated cylinder is used for measuring volumes of liquids. Therefore, they are not for quantitative analysis but for general purposes.
3) Explain how to read a burette. What are the factors to be considered while using burette?
To read the burette, our eyes must be perpendicular to the burette scale. The factors to be considered while using burettes is make sure it does not leak from bottom.
UNIVERSITI TEKNOLOGI MARA
EXPERIMENTAL NUMBER AND TITLE:
EXPERIMENT 1-BASIC LABORATORY TECHNIQUES
MOHAMED FAZRIN BIN MOHAMED ZAMRI
DATE OF EXPERIMENT:
DATE OF REPORT SUBMISSION:
HENDRIE JOHANN MUHAMAD RIDZWAN
GROUP : EC1101B
NAME OF LABORATORY PARTNER:
NAME MATRIX NO
MUHAMMAD DANIAL BIN MUHAMMAD AZIZI 2018408144
NIK AIDIL NAJIHIN BIN SOLAHUDIN 2016475302MUHAMMAD ZAHIRUL AMRI BIN AMERUDDIN 2018214734