- Water/eye solutions should not be directly aimed onto the eyeball, but rather, aimed at the base of the nose. This increases the chance of effectively rinsing the eyes free of chemicals (harsh streams of water may drive particles further into the eyes).
- Eyelids may have to be forcibly opened to attempt eye rinse.
- Flood eyes and eyelids with water/eye solution for a minimum of 15 minutes.
Clothing is also another aspect of laboratory safety it may not seem like it but It plays a vital part in protecting the skin from the harm of chemicals that is why it is advisory to cover as much of the body as possible while dealing with chemicals due to the fact that chemical can be corrosive and cause damage to the skin. The clothing can help by absorbing as much o the chemical as possible leaving hopefully a minor amount of the chemical to react with the skin. Another way of avoiding contact of chemicals with skin is to use instruments in laboratory such as pipits to transfer chemicals and tongues to handle test tubes etc.
Another aspect of safety to consider when dealing with chemicals is diffusion it is a known fact the by inhaling certain chemicals, these chemicals are labelled as toxic chemicals, can cause serious damage with in your body just by inhaling the vapour through the air. One way of preventing this is by closing lids on all chemicals after use by closing the lid you are also preventing spillages so if the container is dropped the chemical remains inside the container.
Within the laboratory there are frequent spillages that’s why it is important to try and prevent spillages and knowing what the effect of a spillage is and what to do about it. When these spillages occur they can be on minor scale or a disastrous scale. This depends whether the chemical is hazardous or not most lab spillages are on a minor scale and can simply be wiped up by using a damp cloth. With hazardous spillages do not attempt the spillage seek someone qualified to attend to the spillage.
A Bunsen burner is very common within a laboratory the importance is safety.
As u connects the Bunsen make sure that the gas pipe is secure and tight. When lighting a Bunsen burner use a splint at arms length and make sure the safety flame is on. This is done by closing the air whole located at the bottom of the Bunsen. Make sure that the Bunsen is securely placed on a heat proof mat in the centre of the table the so if the Bunsen tips over it has less of chance of inflicting injury. Before using a Bunsen burner make sure ties are tucked in, long hair is tied back, any lose items of clothing should be tightened or wrapped up and remove all unnecessary item of clothing e.g. jackets. These safety measures should be met to prevent any risk of fire. In the event of a fire take immediate safety precautions such as turning of the gas as soon as possible and call the teacher our a member of staff, if the fire is on any item of clothing you are wearing which cannot be easily removed stop drop and roll. If the fire is out of your control inform the teacher and evacuate the classroom.
Method
When the experiment was carried out the first thing that needed to be attended to was having all the correct equipment and materials at hand. The following equipment and materials were gathered:
- Copper-An element found on the periodic table as Cu its atomic number is 29 and has an atomic weight of 63.546 and is classed as a Coinage metal. It is a malleable and a good conductor of heat and electricity.
- Calcium- An element found on the periodic table as Ca its atomic number is 20 and has an atomic weight of 40.078 and is classed as an alkaline earth metal.
- Lithium- An element found on the periodic table as Li its atomic number is 20 and has an atomic weight of 6.941 and is classed as an alkali metal. Lithium is used commonly with aluminium and magnesium to form alloys. It is also used in batteries, greases, glasses and medicine.
- Potassium- An element found on the periodic table as K its atomic number is 19 and has an atomic weight of 39.0983 and is classed as an alkali metal.
- Sodium- An element found on the periodic table as Ca its atomic number is 11 and has an atomic weight of 22.989770 and is classed as an alkali metal. Sodium is generally used to make soap and table salt.
- Barium- An element found on the periodic table as Ca its atomic number is 56 and has an atomic weight of 137.237 and is classed as an alkaline earth metal. Small amounts of barium compounds are used in glasses and paints.
- Magnesium- An element found on the periodic table as Ca its atomic number is 12 and has an atomic weight of 24.3050 and is classed as an alkaline earth metal. is used commonly with aluminium and Lithium to form alloys.
- Bunsen burner- A laboratory gas burner invented in 1855 by Roberts Bunsen. The Bunsen burner has a vertical metal tube flows through. The vertical tube has a while located at the bottom of it which is used to admit air. When the whole is closed a yellow safety flame is displayed. Where as when the whole is open it displays a power dull blue flame with a faint blue outer flame with a vibrant blue core used u for combustion and hearting.
- Acid- a substance that is on a scale form 1 to 6 on the ph meter and can be used for neutralising alkalis.
- A metal wire- a metal wire which has a high melting point created out a metal such as iron and is made into a wire with diameter of a about 2mm but yet is malleable and yet maintains high strength.
- Heatproof mat- A mat which is an insulator of heat and has a rough texture to maintain a firm hold on the items placed on it.
- Goggles- Plastic goggles designed to protect the eyes.
Once the equipment had been gathered it was placed and was set-up in the centre of the table. The Bunsen burner was connected to the gas tap and the chemical samples and the acid were in individual beakers. The next step took was lighting the Bunsen burner which was done by turning the gas tap 45 degrees to the right. Then a lit splint was took and placed over the pipe of the Bunsen burner at arms length at the Bunsen burn ignited. Prior to lighting of the Bunsen burner the air whole at the bottoms was closed which meant when I lit the Bunsen burner the safety flame would appear. Once the Bunsen burner had been lit I took hold of the metal wire and created a loop on the end of the wire. Then a sample of the chemical to be tested was took on the end of the loop and placed in to the centre of the combustion flame of the Bunsen burner. The combustion flame was received by opening the air whole. Once the sample was within the flame a closed eye had to be kept on it so we didn’t miss the colour of the flame change. After the colour of the flame had changed the metal wire wash washed in acid and the process was repeated again with a different chemical sample.
Results
As every good scientist knows the results are the main aim of the experiment and recording the results is even more important. Below is a table of all the chemicals and samples I tested and it also states what colour the flame turns when the sample it is table showing my results. The results that I found where very interesting
Evaluation
I will now evaluate my work to date be referring the aim set at the beginning of the assignment and will evaluate and analyse my performance and accomplishment the objectives.
Aim
We are going to carry out a qualitative analysis on our chemicals by flame testing. This process will be carried out by burning an ionic substance into a combustion flame. The results will be recorded by the visual aid of the flame changing colour the test will be carried out on seven unidentified materials.
Shown above is the initial aim which was stated within the introduction. When I first created this aim I thought I would have an easy journey. As I carried out my experiment, the errors that I encountered were many, to my surprise. However, in the end I successfully carried out the experiment coming out with accurate results.
Whilst carrying out this experiment I encountered many unexpected errors and I had to overcome them on the spot. The first error I encountered was the connecting of the Bunsen burner to the gas tap. This was a problem because I could not get the pipe from the Bunsen burner to the gas tap they pipe wouldn’t hold on the gas tap. This problem could not be fixed so I decided the only way around was to switch the Bunsen burner. Once I had managed to overcome the first error as I proceeded with the experiment and encountered another error was that of the acid being contaminated by alkali as someone had dropped a metal sample in to the acid the only solution that I could find to this was to replace the acid. As I continued setting up the experiment I was required to form a loop on the end of my wire. As I formed the loop the wire snapped. Without the loop on the wire it was almost impossible for me to continue with my experiment so I decided to overcome the problem by replacing the wire and creating a looser loop.
As I followed through to the next step of the experiment I encountered problems with this second step the first error was getting the chemical sample to stay on the loop. To solve this problem I created a tighter loop which allowed the powder to stay on the loop. As I continued the experiment I encountered another error. This error was contamination of the Bunsen due to the fact there was an excusive amount of the ionic substance on the loop and was actually falling in to the Bunsen contaminating the Bunsen. This was a major problem because this could actually contaminate all my results. This was an error I spent a fair bit of time on with great difficulty I came to the solution of slightly tilting the Bunsen. With the idea of tilting the Bunsen be impractical and unsafe I still went ahead a continued it. This was a very unsafe method but my only option for fair qualitative analysis. I had overcame the my fine error encountered was when the flame changed colour I could not identify correctly what the colour was e.g. brick red or red and was an error that was extremely difficult to overcome. In the end we overcame this error by using pictures of previous tests. These pictures were the pictures of the actual flames and stated what colour flame was what material. I decided consulted my peers on which colour and substance each test was. From here on I encountered no obstacles or problems due to the fact I thought about potential problems and how to overcome them.
As I have stated above how I had thought about potential problems and how I overcame them. My first potential problem was contamination of the samples. With standing as my first potential I easily overcame it with simple solution of pour out the samples into separate beakers so they would not get contaminated by me accidentally dipping the metal wire in to the wrong substance. Another potential error standing in my way was the contamination of the wire. The wire could be contaminated due to the fact that it may not be totally cleaned by this acid. I overcame this error by changing the wire every 2 substances.
Overall by looking at the problems and potential problems I had I think I didn’t carry out a very accurate experiment. With all the minor problems I think the accuracy was not as good as it could have been.
I think that the method and the equipment and the materials for this experiment are great for maximum accuracy but they do not eliminate the chance for human error.
Over all out of the whole experiment I enjoyed the theory the most due to the fact that it enhanced me knowledge about preparing accurate chemical solutions and it showed me it just wasn’t a basic skill but a crucial skill which involved a high level of accuracy I also enjoyed conducting the experiment even though I encountered many errors I enjoyed finding a solution to them. I also think that this experiment has challenged me mentally in every academic way. It has also helped me to develop personal thinking strategies.
During this experiment I learnt quote a lot and enhanced my general knowledge of chemicals as a whole and I learnt practical skills of preparing chemical solutions which I will be able to use in the future.
Over all this experiment has been an interesting and an enlightening experience which I have gained many skills and much knowledge even though I had encountered many problems I enjoyed the experiment thoroughly and would gladly repeat it.
