Investigation of Some of the Properties of a Pair of Cis-Trans Isomers

Experiment18 Aim To determination the partition coefficient of ethanoic acid between water and butan-2-ol. Procedure . The room temperature was recorded. 2. 15cm3 of the given aqueous ethanoic acid and 15cm3 of butan-2-ol were poured into a 100cm3 separating funnel, using suitable apparatus. The funnel was stoppered and was shook vigorously for 1 to 2 minutes. (The pressure in the funnel was released by occasionally opening the tap.) 3. 10cm3 of each layer was separated approximately. (The fraction near the junction of the two layers was discarded.) 4. 10.0cm3 of the aqueous layer was pipetted into a conical flask and was titrated with 0.1 M sodium hydroxide solution using phenolphthalein. 5. Using another pipette, 10.0 cm3 of the alcohol layer was delivered into a conical flask and was titrated with 0.1 M sodium hydroxide solution. 6. Steps (2) to (5) was repeated with another separating funnel using the following volume: 25cm3 of aqueous ethanoic acid and 15cm3 of butan-2-ol 7. For each experiment, the ratio of the concentration of ethanoic acid in the aqueous layer to that in the butan-2-ol layer was calculated. Result Room temperature: 29? Volume of butan-2-ol: 15 cm3 Volume of 0.2M ethanoic acid / cm3 Volume of 0.1M NaOH titre for aqueous layer / cm3 Volume of 0.1M NaOH titre for alcohol layer / cm3 Partition coefficient K= 5 0.00 2.55 0.796 25

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Investigation on whether Rubber obeys Hooke's Rule

Investigation on whether Rubber obeys Hooke's Rule Plan Introduction Hooke's Rule states that extension of a material is proportional to the tension force applied to it unless the elastic limit is reached, which is the point at which the material no longer obeys Hooke's Rule. There are only a few materials that obey this rule. In this investigation, we will find out whether rubber obeys Hooke's Rule. We will measure in detail the way in which the extension of a rubber band depends on the tension in the band. This will be done by applying various amounts of weights, as it is a continual variation. Hooke's Rule = F = ke * F = Force in Newtons * k = Spring constant * e = Extension in Centimetres Rubber is a natural polymer which is made up of long chains of molecules which are bent back and forth with weak forces acting between them. As the rubber band is stretched, molecules straighten out and allow the rubber band to become larger. Eventually, as the molecules become fully stretched, the long chains will become parallel to each other and can stretch up to ten times its original length. Extra force will make the rubber band break. If the rubber is not stretched to breaking, once the force is removed the molecules tend to curl back again into their original position because of the attraction and cross-links between adjacent molecules. The return is elastic. Hypothesis I

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Pros and Cons of Genetic Engineering

Pros and Cons of Genetic Engineering Introduction The first step to understanding genetic engineering and embracing its possibilities for society is to obtain a rough knowledge base of its history and method. The basis for altering the evolutionary process is dependant on the understanding of how individuals pass on characteristics to their offspring. Genetics achieved its first foothold on the secrets of nature's evolutionary process when an Austrian monk named Gregor Mendel developed the first "laws of heredity." Using these laws, scientists studied the characteristics of organisms for most of the next one hundred years following Mendel's discovery. These early studies concluded that each organism has two sets of character determinants, or genes. For instance, in regards to eye colour, a child could receive one set of genes from his or her father that were encoded one blue, and the other brown. The same child could also receive two brown genes from his or her mother. The conclusion for this inheritance would be the child has a three in four chance of having brown eyes, and a one in four chance of having blue. Genes are transmitted through chromosomes which reside in the nucleus of every living organism's cells. Each chromosome is made up of fine strands of deoxyribonucleic acid, or DNA. The information carried on the DNA determines the cells function within the organism.

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Properties of Waves.

Properties of Waves There are many different waves including water, sound, light and radio waves. All waves have the same range of properties, they can all be reflected, refracted, totally internally reflected, diffracted or interfere with each other. Waves are repeated oscillations (vibrations) which transfer energy from one place to another. Sound energy in the atmosphere is transferred by the oscillation of air molecules. Movement energy in water waves is transferred by the oscillation of water molecules. Amplitude is the measure of the energy carried by it. Frequency (f) is the number of complete wave cycles per second and is measured in Hertz (Hz). Wavelength (?) is the distance between two successive peaks or troughs and is measured in metres, m. Reflection Light waves travel in straight lines but reflecting them using mirrors can alter their direction. Reflection is the bouncing off of any type of wave from a surface. Reflection can be used to guide a laser past obstacles to a receiver. Shiny surfaces such as mirrors are smooth so reflect all light strongly as all the waves pass in one direction only. Rough surfaces look dull as they reflect light in many different directions causing it to scatter. This is called diffuse reflection. If light waves are reflected, the colour of the surface affects the colour of the reflected ray. Concave surfaces are used

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"To Clone or Not to Clone- That is the Question".

One World Essay "To Clone or Not to Clone- That is the Question" For years and years, the cloning of living beings has just been an aspect of science fiction. Although several movies have been created based on human cloning as such, their scientific accuracy has made the general public dismiss them as something not capable of in the near future. When the first ever living clone of a six-year-old sheep was created (to the right), the world was in an uproar. Dolly, the sheep clone named after singer Dolly Parton, had been cloned from the udder cell of an adult ewe by a group of scientists in Scotland. People realized that this breakthrough could be a door to unimaginable technology, not necessarily positive. The notion that this discovery could change the world and lives was beginning to threaten the minds of activists and others. Many of the fears that come with these theories are within cultural and religious beliefs, or from being exposed to too many movies. Films of human cloning depict terrible things that happen to those that tamper with nature. A very famous example of this is Mary Shelley's tale of Frankenstein. Even through historic cases, such as where Nazi doctor Joseph Mengele flees to Brazil after the crash of the Nazi rule and World War II and attempts to use Hitler's tissue to create several more Hitlers, people have wondered whether it was truly possible. When

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The use of pectinase in fruit juice production

The use of pectinase in fruit juice production I predict that there will be no juice produced to the apple sauce that had no enzyme and juice will produce to the apple sauce that had pectinase. A control is carried out in order to compare the rate of reaction between with pectinase and without pectin's. Pectin --> sugars + galataronic acid Pectin is a substance which helps to hold pant cell walls together. As a fruit ripens the plant produces proteolytic enzymes, which convert the insoluble protpectin of the unripe fruit into more soluble forms, causing the fruit to soften. When fruits are mashed and pressed to form juices these more soluble forms of pectin enter the juice, making it cloudy and causing the colour and flavour to deteriorate. Enzymes are specific in the reactions they catalyse, much more so than inorganic Catalysts. Normally, a given enzyme will Catalyse only one reaction, or type of reaction. The enzyme has an active site that helps it to recognise its substrate in a very specific way. Just like a key only fits into a specific lock, each enzyme has its own specific lock; each enzyme has its own specific substrate. This is called the lock and key theory. The enzymes never actually get consumed in the process; they just increase the rate of reactions. When enzymes denature the heat starts to destroy their shape and structure. The shape of the enzyme is so

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To investigate the effect of temperature on the enzyme catalase.

To investigate the effect of temperature on the enzyme catalase Aim: To investigate the effect of temperature on the enzyme catalase Apparatus Celery extract (catalase) Labels 20 Volume hydrogen peroxide Distilled water 6 100cm beakers 20cm and 50 cm measuring cylinders Balance Stopwatch Trough Clamps & stand 50cm conical flask + bung + tubing + 3 way tap 0cm syringe Beehive shelf Gas syringe Goggles Water bath at 25 & 35°C 250cm beakers & thermometer for water bath Method .Weigh out 1 sample of celery extract of 10g in a conical flask. 2.Place in a water bath at 25°C. 3.Place about 20cm hydrogen peroxide solution in a container in the same water bath. 4.Leave for 10 min to equilibrate. 5.Set up the apparatus as follows: -Fill a trough with water -Fill a measuring cylinder with water and invert in the trough (ensure that no air bubbles are in the water) -Secure the cylinder with a clamp & stand -Position the bung and 3 ways tap to fit on a conical flask, ensure that this can be held in place with a clamp & stand -Put the end of the tubing in the measuring cylinder 6.Make sure that the tap is closed and fill a syringe with 10cm hydrogen peroxide from the water bath. 7.Take the first conical flask containing the celery extract; arrange the apparatus as above and empty the syringe into the flask closing the 3-way tap start the stopwatch.

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Too Much Information: Genetic Testing

Too Much Information: Genetic Testing Biology OAC ISP Essay - By Daniel Perez Genetic testing offers a whole new world of information about us and how our bodies work. The data we get from delving into our own genetic code can help us to cure or even prevent disease, stop medical conditions such as cancer or cystic fibrosis from even manifesting, or even correct these sorts of errors before birth, and many other beneficial uses. However, at this point in time, all of this is beyond us. We have no miracle cures, no 'magic bullet' with which to fight disease or genetic conditions, in fact, our understanding of the genetic code is so limited that it's as if we cannot see the forest for the trees. We have taken our first baby steps into understanding human genetics with the completion of the Human Genome Project, and now that we have the big picture, we can begin to interpret it. Through information gleaned from our DNA, we now know that there are certain medical conditions that are caused by certain patterns within the genes. Some examples of these genetic conditions include Tay-Sach's disease, Bloom syndrome, Deafness, cystic fibrosis, and many other diseases (http://www.einstein.edu/e3front.dll?durki=7158). Although many of these conditions are fatal, the ones that are not can be treated early, even before symptoms develop when possible, or if not treated, at least monitored

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Use of a Redox Indicator to show Dehydrogenase Activity

Use of a Redox Indicator to show Dehydrogenase Activity Hypothesis: As the temperature increases, the time taken for the colour change to occur will decrease. Introduction: Triphenyl tetrazolium chloride (also known as T.T.C) is an example of an artificial hydrogen acceptor. It is a redox indicator which is colourless when oxidised, however when reduced, it produces a red, insoluble precipitate called 'formazans'. T.T.C can therefore be used to investigate the enzyme activity of dehyrogenase enzymes by showing a colour change when they are present. The purpose of this experiment is to see what effect temperature has on the activity of dehydrogenase enzymes within yeast cells. Materials/Apparatus: * Actively respiring yeast suspension. This is prepared by adding 10g of dried yeast to 1dm3 of distilled water, followed by mixing in 50g of glucose. This mixture should be allowed to stand for 24 hours before the experiment takes place. * Tiphenyl tetrazolium chloride is used as a redox indicator to investigate the activity of dehydrogenase enzymes when yeast suspension is exposed to different temperatures. * Distilled water for the preparation of the yeast suspension. * Test tubes to place the mixture of yeast and T.T.C. * Test tube rack to allow the test tubes to stand upright in the water baths. * Incubator to allow enzyme activity to occur at different temperatures *

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