UNIT 2. LEARNING AIM D. REWIEW PERSONAL DEVELOPMENT OF SCIENTIFIC SKILLS FOR LABORATORY
WORK.
In this assignment I am going to talk about the skills improved in all the practical in this unit, I am going
to evaluate each of them step by step and personal development and achievement in workplace.
Before this course I did not know how to use some of the equipment that we used in the practical like
burette, graduated pipette, weigh balance, use of chemicals and how they react, measuring liquids in
weigh balance and measuring cylinder and how to do accurate measuring.
SKILL BEFORE AND AFTER THE PRACTICAL AND WHICH SKILL I HAVE TO DEVELOP OF EACH PRACTICAL.
Standard solution.
When I started the course, I knew how to use a weight balance and measure substance without
measuring the container such as weighing boat. I knew some of the equipment also how to use. The
skills gained after completing unit 2 I learn how to measure the volume of a liquid with a pipette and
burette, how to work out the mass of the substance required by using formulas, use the volumetric flask
to make up the solution also I learnt how to manage health and safety by following the teacher and his
instruction and which PPE equipment is useful in the practical. The skills to develop further are
practising more with volumetric glassware specially with pipette and burettes to identify accurately and
quickly by the eye level the bottom of the meniscus in the graduate line and reduce errors while doing
practical.
Titration.
When I started the course, I knew how to weight the mass of a liquid in the conical flask in the weight
balance also I ability to use the plastic pipette. The skills gained after completing unit 2 I learnt how to
use pipette and transfer the liquid into a beaker, use indicator drop by drop, read the volume of the
liquid and record the results, find out the concordance, work pout the calculation of unknown
concentration and find out the balance equation of the reaction, how to make a suitable graph and label
the x and y axis, calibrate the equipment safely, we learnt how to find out the unknown concentration of
a substance, I learnt the risks of the practical and how I could manage it for example 0.1M of
hydrochloric acid is irritant which we need to wear a lab coat, gloves and goggles to prevent any harm to
ourselves, the results of the practicals was repeated 4 th to get concordant result, we have learnt that the
first result is a rough result which means it not valid for calculation due errors. The skill to develop
further are practising more how to use correctly the pipette and find out the bottom of the meniscus by
the eye level, this skill is the most I need to develop to reduce uncertainty, contamination in the
equipment that could affect into my results.
Colorimetry.
When I started the course, I knew how to use plastic pipette. The skills gained after completing unit 2 I
learnt how to work out the mass of the substance, make up the solution in the conical flask, use the
colorimeter and read properly the results of dilutions, making dilution with different volumes and
concentration, how to calibrate the colorimeter and manage health and safety while doing the practical.
I learnt the risks that could happen while doing the practical. I learnt how to carry out colorimetry and
the uses of colorimeter. I learnt how to make dilution using graduated pipette. I learnt how to calculate
from transmission to absorbance using a formula, I learnt how to plot a graph and find out the
, concentration of the two unknown concentration. The skills to develop further are practising more doing
dilution to get accurate dilution and reduce errors in the results.
Chromatography.
When I started the course, I knew how to grind mixture into the mortar. The skills gained after
completing unit 2 are calculating the Rf value, identify the unknow amino acid by look at the
chromatograph, putting the solution into the beaker but bellow the mixture of the chromatograph. I
learnt how to manage risks that could happen while doing the practical and identify hazards. I learnt
how to measure the distance which the solvent rises and the distance which the mixture rises and
calculate the Rf value. The skill to develop further are practising more the practical as in the first time I
did chromatography the mixture was dissolved into the solvent, so no chromatograph was happened.
Cooling curve.
When I started the course, I knew how to weigh the substance into two decimal places and how the
read the temperature into analogue and digital thermometer. The skills gained after completing unit 2
are know the different types of thermometers and which one is more accurate, calibrating thermometer
into two different ways, making an appropriate graph for the cooling curve and identify and calculate
the rate of cooling of liquid phase, solid phase and identify where is the melting point of the two
substances. The skills to develop further are practicing more how to read into an analogue thermometer
and use the two different thermometers into one substance to see how accurate the results are.
I learnt how to complete a Risk Assessment for each of the practical using websites or HAZCARDS. I
learnt how collect the results for each practical and use the appropriate formula for the practical.
ANALYSE AND EVALUATE SKILLS DEVELOPED.
I will explain the skills used when carrying out the practical of unit 2, any problems that happened in the
practical and which solution I gave to solve them. Which judgements and improvements could I give to
the practicals.
In the first assignment I learnt how to find out the concentration of hydrochloric acid and make a
standard solution. The first assignment consists of making standard solutions and titration. Titration had
two parts, the first part was found out the concentration of hydrochloric acid and the second part was
ph reader. The last part of the first assignment was colorimetry which consisted of finding out the
concentration of two unknown solution by using a graph.
The second assignment was about cooling curves, measuring the temperature of stearic acid and
paraffin wax. We made a cooling curve to identify where the melting point is and find where the liquid
phase and solid phase is.
The third assignment was about chromatography. We used different types of chromatography to
separate and identify mixtures, we used paper chromatography, TLC plate and identification of amino
acid using paper chromatography.
Standard solution
Standard solution is making a chemical solution with known concentration. The first step before using
any equipment is to calibrate them and test how calibrated and accurate, they are. The first process of
