Lab experiment- sepation techniques.

In this lab experiment, we learnt about separation techniques and its applciations in our daily lives. Adding on the Chromatography experiment, we did evaporation to dryness . Evaporation to dryness is an interesting process. As its name suggests, a solution is evaporated to dryness to get the soluble solute from the solution. For example a salt water is evaporated completely, and its residue would be salt a perhaps a little impurity. I find this process interesting as it is closely linked to Crystallisation which evaporates almost all the solvent till a bit is left. The solution is then left to cool down. Next because there is a small quantity of solvent, satuation point of the solute is reached and thus when the solution is filter, crystals is the residue. Crystallisation can be used to get sugar sucrose from sugar beets. This is a video of evaporation to dryness, enjoy

Separation Techniques

After the group work, later on in term 3, we learnt more about separation techniques. We learnt that there were several separation techniques such as filtration, evaporation to dryness, distillation, magnetic attraction, crystallisation, and chromatography.

It is interesting to find out that different techniques have different applications, they also have different apparutus in the separation process. For instance, crystallisation is used fir production of silcon cafers for microchips, and also production of sucrose sugar from sugar beets. Those sweet delicacies which we enjoy also goes through a separation process before we can eat them.

Next is the chromatography process. Chromatography is the simple process to test for a substances in a dye, etc. I did the simpler process of chromatography which involves using a chromatography paper with a dye, soaked in a solvent, preferably alchohol. The substances in the dye then separates as they have different solubilities. What I like about chromatography is that this simple yet useful application has been helpful to the society as it is used to test for banned substances too. For example, police use urine samples for chromatography so that they can find out if the suspect is taking drugs.

http://http//www.youtube.com/watch?v=9Oy98D6if1c

Separation Techniques Group work

Separation techniques was a topic which was onlly briefly covered at first. That was during the beginning of the june holidays. We were split into groups, our objectives was to use the given apparatus and solve a problem stated on an e-learning site.
Back then, we knew little about separation techniques, but still, my group fared much worse than other groups as we only got 1 ace points. When I reflect back on our work and compare that to group 2 from my class. I realised why our work was really insufficient. You can go to science excite, the blogpost on Home Learning PBL to find out why.
I will just brief you why now. My groups work is bacsically not clearly stated, it lacks reasoning and explanations, also the theory and keywords used were wrong. While on the other hand, 1a2 groups 2's work did a brilliant work because,

1)They first pointed out the main aim and the problem to be solved of the experiment
2) Apparatus available
3) Step by step procedure, including pictures and diagrams, most importantly was their explanation for every point they have said and also, their organisation makes it easier for the reader to read the work.
One example would be that they first distinguished the different properties of the substances present in the poluted sea water.

Miscible or immiscible: 1)oil, 2)alchohol( liquids)
3) Sand and gravel (Solid)
4) Broken glass bits (Solid)
5) Remnants from dead organisms (Solid)

They also stated the apparatus needed such as separating funnel, and fractional distillation. This will give the reader a better idea of how the sea water is separated from the inpurities, together with the visual aid of the diagrams and pictures.

The bigger scale project cannot be successful as the cost is high and not all inpurities will be removed. This can thus be related to my ACE project in my earlier post about NEWater. The NEWater process includes using reverse osmosis, micro-filtration and uv disinfection. You can find out more about my ACE project in my earlier post.

Elements, Compounds and Mixtures

Elements is the simplest kind of matter and there are over 100 of them. Elements are grouped in a periodic table which consists of periods and groups. Elements in the same period are lined up according to their atomic number on the bottom left-hand corner, while the atomic mass is on the top. Periods are horizontal. Elements in the same group share similar chemical properties, and are vertical. Each element has an special symbol. Fron the left to the right of each period, the elements on the left are metal, and non-metal are on the right. Metals and non-matals have different properties, for example, iron and carbon. Iron is ductile and has high density while carbon is brittle and has low density.
Elements also have different uses. Aluminium is used to make foils and drink cans while, Chlorine is used to make bleach.
A compound consists of 2 or more elements chemically combined together. A mixture consists of 2 or more substances which are not joined together chemically, and it can be made up of elements , compunds or both. Elements in a compound are have different ratios, like 2:1, and compounds have a chemical formula. metallic elements always have their names come first in the compound's name. Mixtures have no chemical formula no given ratio. Compounds can be separated chemically by releasing energy. Mixtures can be separated by physical force.
Something interesting I did in the lab was to burn a magnesium with a bunsen burner. Miss leong asked gave everyone a small magnesium plate. We then use a pair of tongs to burn it in the flame. After burning the magnesium, it lit up into bright white light. The originally grey magnesium turned white after cooling it. This proves that elements are chemically combined and the release ofenergy as light was produced and the magnesium combined with oxygen to become magnesium oxide.


Here is a video I have found, enjoy :D

Term 3 Progress

In term 3, we were to be tested on elements, compounds and mixtures, solutions and suspensions, separation techniques.
In elements, compounds and mixtures, I learnt about the different elements which scientists have found out and named. These elements are put together to make a periodic table. Each elemtent has a atomic number and mass. While in a periodic table there is periods and groups. Elements in the same group have similar chemical properties. My weak point in this chapter is that I fount it difficult to remember what element has what type of chemical properties, and what symbol represents which element. I have seen an improvement of my memory for the different symbols as I went through the periodic table throughly. I would like to read the periodic table more often in future, so as to better remember the symbols and not forget them in future.
Compound is made up of 2 or more elements, which are chemically joined, while mixtures, are 2 or more substances and are not chemically joined. I am know about the features of compounds and mixtures well, but I am not sure what substances are in a given compound, mixture. This is evident in the term 3 class test, as I have got three out of four questions wrong. I believe I had not cover this point well during my revision and I will pay special attention to this.
Separation techniques is one chapter which I have learnt online through e-learning. I have improved steadily in writing processes of separation, but I still lack of some points, rather key words, to make it the process more smooth. My problem lies with the chromatographhy separation. Through the term 3 class test, I have found out that "smudge" cannot be used when explaing when ink should not be used as the starting line. This is because it is not a scientific word. The word "absorb" also cannot be used as the proper term should be dissolve.

Term 2 Progress

In term 2, miss leong taught us about graphing techniques,measurements and units, mass, weight and density, kinetic particle theory.
After learning about the basics in term 1, we moved on to using our skills in new chapters, and in the process learning more. We first learnt about graphing technique. It is a important technique to remember, as many a time, we are required to anaylse or draw a graph. Thus, graphing techniques is essential for us. At first my graphing techniques were not that good. I had mistakes with my axis , points. Each point is worth 2 marks, and there is a total of 4 points. So not knowing how to do 2 points is actually quite a big mistake. Miss leong then gave us a pep talk on graphing techniques to give us a clearer idea of what to do in future. i realised that my graphing skills have improved after much practice, so is my anaylising of graphs. Measurements and units, is also another problem. I have an issue with remembering some of the different names for measurements and units, plus, my conversion is terrible. i keep getting it mixed up. So I went to read the notes on measurements and units which miss leong gave the class. However, during term 2's test, my marks for measurements and units, and conversion, were still not that good. I hope to improve on this part, so because i loss marks here.
For mass, weight and density, I am more confident in this chapter as I am know the weight is the amount of gravational pull of a large matter, and mass is the amount of matter in the object. Density= Mass/Volume. However, I am looking forward to improving my answering skills on this chapter. I am unsure when it comes to questions involving the percentage of two different substances in a matter, and the question asks me to find out the density of the object given.
Kinetic partical theory is fine for me. I am able to understand the concepts of kinetic particle theory in all three states of matter. The only thing I need to work on is my usage on the keywords required to explain the process of particle movement during a change of state.
I will work on these chapters and in order to learn from my mistakes.

Term 1 reflection

In term 1, miss leong teached us on science as an inquiry. They are the raw basics of science, such as some safety precautions we must take note of, names of purposes of different apparatus in the laboratory, etc.
I am glad that basics come first, because I feel that we must know them. For me, I am just grateful that I know my basics well enough, enough to get an A1 in the term 1 test. I am pleased that I managed to get an A1, and buck up from the practice test, in which I got only 24/35. That is one good point. I believed that my revision on the notes miss leong gave, both online, and hard copy, plus my assignments made me realised my mistakes in my daily work. However i hope that I will be more firm with my facts so that unnesccesary mistakes can be avoided.
I am looking forward for future improvement on my experimental skills, such as measuring and observing skills. I feel that my observing skills still can be improved, for instance to find a particular pattern faster. Also, my answer have tendency to be inaccurate. Thus my experimental questions in that practical will be badly done.
As for my measuring skills, I am hoping that my techniques would improve, so as to get a accurate answer, and not stumble over a question asking me to elaborate on an apparatus use and features. If I can get back all these marks, I am sure my marks would improve. Anyway, this is only the basics, so I must expect tougher questions and work doubly hard.

Lab experiment- chromatography

During this experiment, Miss Leong teached us the basics of chromatography, and how to carry out chromatography.

Chromatography is a simple process, to separate substances in a solution. It is a effective way to find out if a certain, or unique substance is present in a solution as all substances will be separated. Different substance have different colours. For example, a blue ink may consists of blue and black ink. Some solution, or dyes have only one coulour, this means that the solution is pure.
There are several ways of conducting chromatography tests, but a simpler method would be to use a chromatography paper paper with two drops of ink soak it in a ethanol and water mixture. The inks must be placed above a line drawn by a pencil with the mixture directly below it. This is to ensure the the inks do not dissolve into the mixture beforehand. Also the line must be drawn in pencil as ink will dissolve in the mixture and disrupt the results. Thus, as the filter paper absorbs the mixture, substances in the ink get separated from each other, as different substances have different rates of dissolving, also due to the solvent used.
Generally I like chromatography as it is a very interesting process to me. For instance, invisible ink spots in the chromatography paper can be .made visible via iodine. I find that this is really amazing as you can find out any substance in a solution by using chromatography, that is how authorities find out if some people misused drugs, by taking their urine sample. The experiment was memorable for me as i forget that lead cannot be dissolved in a solvent, as I used my highlighter which is uses lead. Consequently, the lead did not dissolve in the ethnol solution...

Nanotechnology

Hi everyone,
today, I am going to talk about nanotechnology. Nanotechnology is used to control matter in the range of atom and molecule sizes. It also used to manufacture materials of 1 to 100 nanometer sizes.
Nanotechnolgy can be used to device physics or to create materials used for applications, on an atomic scale. It can create materials in applications such as medicine, electronics and biomaterial. I feel that witht the introduction of nanotechnology, the future would see many applications produced by nanotechnology which will bring a new dimension to our life. Scientists have carried out experiments sbased on nanotechlogy. One exaple would be the a atomic sized guitar.
Also there has been a reported experiment which is about nanorobots that will be used in medical science.
For instance, nanotechnology can be used to to make nano-particles which can be released into the bloodstream through drugs. These nano-particles use targeting devices to treat the cells in the human body. I believe this is a more efficient way to get better and faster results, improvement in a patients condition as the drugs carried by the nano-particles are directly transported to the cells. This reduces side-effects. Also it is better than conventional methods where the drugs enters through your mouth or bloodstream by injection.
With the current advancement of nano-technology, I believe the future for technology is good as man looks to upgrade his life in a new pespective.
http://www.google.com.sg/imgres?imgurl=http://www.lutherie.net/nanogtr.GIF&imgrefurl=http://www.lutherie.net/nano.guitar.aip.html&usg=__gJ1ExPoZjnLJ4AdNkBIEfFDNMrU=&h=287&w=508&sz=131&hl=en&start=0&zoom=1&tbnid=JbZaiqyRB-7VQM:&tbnh=124&tbnw=220&prev=/images%3Fq%3Dnano%2Bguitar%26um%3D1%26hl%3Den%26rlz%3D1T4SUNC_enSG371SG372%26biw%3D1345%26bih%3D467%26tbs%3Disch:1&um=1&itbs=1&iact=rc&dur=290&ei=TXB6TMrnE4eycZXHyewF&oei=DnB6TIfwA4GPceK7ifMF&esq=6&page=1&ndsp=10&ved=1t:429,r:0,s:0&tx=138&ty=45

New strain of super-bug

Recently, scientists have warned of a "super bug" which could potentially spread word-wide. This new strain of bacteria,NDM-1 if even resistant to the strongest anti-biotics,
carbepenams.
As carbepenam is regarded as a last resort anti-biotics, this shows the severity of this matter, sending a message to the world. NDM-1 is going to spread quickly. Scientists anaylised that NDM-1 has a certain gene which alloes it to spread and also to diverse.
I belive that with the current research on NDM-1, everyone have to be alert for this "super bug". Once it spreads, it could lead to another major health problem.
While scientists are trying to stop bacterias from evoving, no matter how advanced the technology is, it is impossible to completely prevent forming of new bacteria, or a health threat. With NDM-1's unique gene, it allows the bacteria to evovle more quicky thus making it more difficult to curb.
While there is such a report on an impending health worry shows, the chage of bacterias are multiple and Man cannot predict what will happen next. I hope that people will take this more seriously, so as to prepare themselves on what to do in case of a crisis.

Regards,
Aceson

Why does the egg sink in tap water but floats in salt water?

The egg has density which is denser than tap water and is more compact in terms of g/cm3. But after salt is added to tap water and mixed, the less dense salt makes the combined density of the tap water and salt lesser than the egg although the mass of the salt water has increased from that of the tap water. As objects which are less dense floats on denser objects, the egg floats on the salt water.

Why and how does the density of the water change when salt was added to the water?

Salt has and density which lesser than water thus making it less dense. As Density=Mass/Volume, g/cm 3 of salt lesser than water. Therefore, when salt is added to water, is stirred and mixed, their combined Mass/Volume or rather density per g/cm3 is lesser than the oure water before .