When doing these investigations, I have researched and done practicals to finish these assignment.There are four kinds of techniques that I have learned and improved, Chromatography, Calorimetry, Titration and Colorimetry. With these four techniques, this will help me when I join university or go for work on the science section, as I have the upper hand of having experience and skills that were developed . This techniques will also help me gain confidence handling these practicals, as I will know what I will be doing and that the experiment is accurate and reliable. I Also gained practical skills in a lab and help me with upcoming assignments and experiments in the future.To help show that I improved, this table will show the skills at the start and how it grown and the possibilities it still has.
skills gained at the startSkills after 2 unitsPossible growth in the futureweighing to 1 decimal point Weighing to 3 decimal pointWeighing liquidsDissolving solidsDissolving a fixed amount for solutionDissolving for making a serial standar solutionTitrating using a indicator solution Titrating using a Ph metreTitrating using other kinds of probes like a temperature probeDiluting chemicalsDiluting exact amount to make standard solutions Making dilutions accurately on a serial basis Transferring liquids with small pipetteTransferring liquids with a bulb pipette and measuring itTransferring liquid with a micropipette and measure is accuratelyMaking a simple paper chromatographyAble to carry out a TLC(thin -layer-chromatography) and measure it’s RFUsing a solvent to make the experiment more effective resultMeasuring distance with rulerUsing mm rather than cm to measure distance accuratelyBeing able to use a digital rulerMeasuring temperature with a thermometerKnowing to calibrate it and adjust the resultsBeing able to use a infrared thermometer and data loggerUsing basic protective equipmentUsing appropriate protective equipment in different experimentsUsing appropriate protective equipment in the right experiments and place chemicals on appropriate places.Working under supervisionWorking independently with little help from othersWorking independently and using my skills confidentlyMeasuring liquid with a measuring cylinderUsing a more accurate way such as bulb pipettes Using a mass to measure a liquidUsing the right equipmentUsing a better equipment than the previous one to get a more accurate measurementUsing better equipment to get more accurate results and being able to use it properly.There is a number of areas I improved, of course there are others that have also not and also still need some more to gain. Thus there is many ways to make one better.For example when I was starting out and was doing paper chromatography, we only used a simple chromatography paper which is simple to do, but as we started to use the TLC paper there were some mistakes such as accidently touching it and marking a hole into it whiles trying to make the dot darker.
When we were making a dot lt was needed to be 2mm which was small, I learned a techniques were the capillary tube was heated by a bunsen making the capillary tubes hole smaller, making the dot smaller my classmate tried this but, did not work well and takes time so I did not use it. But as it might be useful I saved it in my brain. This experiment needed follow the instruction accurate as this may change the outcome of the results, like how much is solvent is needed in a beaker and when to pick the chromatography paper out of the beaker. If these are not carefully followed then the results might change. Also in this experiment I gained a technique, which is slowly inserting the paper so there won’t be any splash that will hit the paper.Another skill that I gained and developed is the use of a colorimeter, these uses the colour of an liquid and measure the absorbance of light calculating its concentration.
After this I used the results making a graph and imputed them, from there I calculated the concentration of both unknown samples. It was my first time using a colorimeter but as I kept using it a grown confidence in handling it. Another skill I gained it the use of a micropipette, this pipette was used to measure the amount of dilution needed and the solution that was needed. This pipette was similar to the bulb pipette but different, at first I had difficulty reading it but I got around it.
As it was the same as the bulb pipette I used my thumb to hold the liquid in the pipette and slowly make a hole, making the liquid decrease. This technique was difficult at first but as I used it more I gain the the skills to do it accurately and properly. At first I would go over the intended line and needed to reset it but I got more used to it and less mistakes were made. On these task I also use a burette for titration, some mistake occurred like forgetting to release the bubble and sometimes going over the intended lines making the results untrustworthy.
When using the burette you were suppose to be eye height of the liquid inside, I know why this is important because it can affect the accuracy, but at times I forget to do this but I gradually remember to do so. It is also important to close the tap before pouring down anything into the burette, as if it’s not closed, it will flow out and worst it will get diluted into the solution which is under it, making you do the experiment again. When making the solution I needed to use a balance which measure an items mass, when I used one I make sure to calibrate it properly.
When measuring the powder I would calibrate it first and place the powder in. I used to press it instantly and not wait for the balance to stabilize but as I realize it will affect the accuracy of the balance I started to wait a few second before I calibrate it, this is also true when I measure anything in a balance and other digital measuring device as the numbers will flicker until it stabilize. The balanced we used was a balance with only measure up to 2 decimal point, I only use this as it I thought it was enough, but as it restricted the accuracy in my calculation, I would use a more accurate balance than a two decimal point one.
There are other balances which are more accurate than these and if I I’m able to use I will as this can make the results more accurate.When carrying titration I have improved, at the start I forget to release the bubbles making the amount of liquid outputted inaccurate, I keep outputting too much or too little making it inaccurate and I used to be slow at it. But as I did it for few more time I became more proficient, I made sure to inspect if there’s any bubbles inside the tube and slowly make and accurately add the right amount of liquid.
I also improved in mixing chemicals, when the HCL is mixed with the Sodium Carbonate, at first I would stir it with the probe but as I was told this was not recommended I realized why, as some of the solution might get stuck on the probe. When I used to mix both HCL and solution effectively my results were everywhere and so I tried mixing it properly by swirling it rather than stirring with the pH metre, this then made my results more believable in my eyes.When I carry on this experiments there are many instrument that needs to be calibrated, at first I turned blind eye to it, but as I needed my results as accurate as possible I calibrate instruments and equipments to gain an accurate results. The first thing I calibrated was a pH metre, what I needed to do was to dip the pH probe into a beaker which has a buffer solution.
There were three buffer solution pH 2, 7, 10 I placed all three into their own beaker and not calibrate the pH in the stock solution as this will contaminate each one of them, when I did this at first I made a mistake of only using one beaker with make the calibrate, but at the second try I used three different beakers. I also calibrated a thermometer and a digital thermometer, a digital thermometer is pretty easy as you only need to press calibrate. As errors can occur on technologies and needs batteries it wasn’t my first option. Calibrating these thermometer used boiling water and ice water, for the boiling water I heated with a bunsen, but for ice water, it took time to prepare.
I place the ice into a beaker and added water into it, after that I waited for a minute so the temperature of the ice is the same as the water, then I proceeded to calibrate. The thermometers were placed in but it I didn’t make it hit the beaker as the beaker glass has a different temperature than the really water, this was also the same to the boiling water.When carrying out titrations I became better. At first I did a rough titration trying to find out were the neutralizing point was and where it would stop decreasing. As I became more skilled at it I was able to control the tap accurately adding the right amount onto the solution. I can also use the pH probe properly and determine the accurate results.
I repeated the experiment three times so I can get a average and have a more accurate results.
