Obtain pure samples of Ethanol (CH3CH2OH) and Ethanoic Acid (CH3COOH) from fermented Yeast (Saccharomyces Cerevisiae).
PREPARATION OF ETHANOL AND ETHANOIC ACID AIM: To obtain pure samples of Ethanol (CH3CH2OH) and Ethanoic Acid (CH3COOH) from fermented Yeast (Saccharomyces Cerevisiae). BACKGROUND INFORMATION: The use of yeast in food production is the oldest and most extensive contribution made by any group of microorganisms. A most common substrate that yeast can work with is GLUCOSE. Glucose is a monosaccharide, which are sweet crystalline sugars that dissolve easily in water to form sweet solutions. Monosaccharides have the general formula (CH2O)n and consist of a single sugar molecule. Glucose is the simplest and most common monosaccharide. It is a Hexose sugar and therefore has the formula C6H12O6. Glucose can exist in two possible ring forms, known as the alpha (?) and beta (?) forms: The hydroxyl group on Carbon atom 1 can project below the ring (? glucose) or above the ring (? glucose). Molecules like this, which have the same molecular formula but a different structural formula, are said to be ISOMERS of each other. One type of isomerism, called sterioisomerism, occurs when the same atoms or groups, are joined together but differ in their arrangement in space. The existence of two isomers of glucose is important because it is linked to the way in which polysaccharides are formed and subsequently their roles. A glucose molecule can switch spontaneously from the open chain form
Rate of Reaction
Rate of reaction coursework Does changing the concentration of an acid affect the rate of reaction? Aim: To investigate the effect of the concentration of an acid on a reaction rate. Hypothesis If the concentration of the acid in the reaction between calcium carbonate and hydrochloric acid is increased, then the reaction rate between the two solutions would also increase. For many reactions involving liquids or gases, increasing the concentration of the reactants increases the rate of reaction. In a few cases, increasing the concentration of one of the reactants may have little noticeable effect of the rate. However, we must not assume that if you simply double the concentration of one of the reactants that you will double the rate of the reaction. It may happen like that, but the relationship may well be more complicated. Suppose you have a reaction which happens in a series of small steps. These steps are likely to have widely different rates - some fast, some slow. For example, suppose two reactants A and B react together in these two stages: A (aq) -(very slow reaction)- X (aq) + Y (aq) X (aq) + B (aq) -(very fast reaction)- other products The overall rate of the reaction is going to be governed by how fast A splits up to make X and Y. This is described as the rate determining step of the reaction. If you increase the concentration of A, you will increase the
The effect of Acid Rain on Seed Germination.
Biology Investigation - The effect of Acid Rain on Seed Germination. By Remy Kynaston-Smith Prediction I believe that the acid rain will drastically effect the seed germination. I predict that the lower the pH of the acid rain, the fewer number of seeds will germinate. I also predict that the stronger the acid, the shorter the overall length of the seed's shoot and root will be. At the very lowest pH of the acid rain I predict that the seeds will not germinate altogether. At the lower pH values, seed germination will be very few seeds out of the set amount. However, as the pH value gradually increases then so will the number of seeds that actually germinate, until at the higher pH values all of the seeds out of the set amount have germinated. The length of the shoot and root together will also slowly increase as the pH becomes less acidic. I predict my graph for the relationship between the shoot and root length against the acidity of the acid rain to look similar to the graph drawn above. I have predicted this because I believe that this particular relationship between the shoot and root length against the pH value of the acid rain to not be directly proportional. This is because the acid in the rain damages the seed so that it can no longer germinate as well as it could before. Inside the seed are enzymes which speed up reactions so that the seed germinates quickly and
Finding out how much acid there is in a solution.
Finding out how much acid there is in a solution. PLANNING During the extraction of a metal from its ore sulphur dioxide is often produced. This is converted to sulphuric (VI) acid and sold as a useful by product. The equation for this titration is: Na2CO3 (aq) + H2SO4 (aq) Na2SO4 (aq) + H2O (l) + CO2 (g) This experiment will be involving an acid and an alkaline. I will be mixing both of these together to find out the concentration of the acid in the solution. I am going to use the method of titration to find this out. Titration is the process of determining the volume of one reactant solution, which exactly reacts, with a given amount of another reactant. We are going to be finding out the concentration of sulphuric acid by adding it to a sodium carbonate solution. Once neutralisation has occurred, this will be the end of the titration. We are told that the concentration of sulphuric acid will be between 0.05mol dm-3and 0.15 mol dm-3 . We are going to use the method of titration to find out the exact concentration. We are also going to be using an indicator. There are many different indicators, which have different properties because the indicator changes colour at different pH numbers therefore the right one should be used which will suit the chemicals being used in the titration. The titration will involve a
Investigate 'How much gas is released when a metal reacts with an acid.'
Chemistry Coursework Planning In my experiment, I am going to investigate 'How much gas is released when a metal reacts with an acid.' When I do the experiment, there will be many hazards that I will have to face and control so that there are no dangers to others or myself. First, I will have to wear my laboratory coat and safety glasses, as this is a compulsory obligation that must be undertaken in order to decrease the amount of accidents that can happen to the skin and eyes. I will have to be careful when handling the acid as acid is an irritant and can therefore cause injury easily, if spilt on someone's hand, for example. In order to keep the number of injuries to a minimum I will not carry acid around the classroom and I will make sure that any container holding acid is nowhere near the edge of a table or somewhere that it can be knocked off. If I do spill some of the acid I will alert the teacher to make sure that it is safe for me to clean it up. As well as this, I will have to be careful when using glass products, which will be quite frequent in this experiment. Glass can very easily be broken and can cause people to cut themselves quite deeply and if it gets into the eyes, it can cause blindness, in extreme cases. In order to keep the breaking of class to a bare minimum I will make sure that my hands are dry when carrying it so that it does not slip out of
Investigating the effects of varying pH levels on the germination of cress seeds
PLANNING & PREPARATORY WORK I will be investigating the effects of varying pH levels on the germination of cress seeds. A seed is a fertilised and ripened ovule, consisting of the plant embryo, varying amounts of stored food material (endosperm), and a protective outer seed coat (aleurone layer). The embryo secretes hormones such as cytokinin, and indole acetic acid, which promote cell division. The endosperm contains insoluble food stores including starch, proteins, and lipids, all of which are used in the initial germination stages. The aleurone layer contains proteins, and under the influence of gibberellic acid (manufactured and secreted by the embryo) synthesises amino acids into hydrolytic enzymes such as -amylase and a protease. These enzymes are then used to hydrolyse starch ( glucose, and proteins ( amino acids for further growth and development. The scale used to measure the acidity or alkalinity of a solution is the pH scale, which generally ranges in values from 0-14. Acidic solutions have pH values below pH 7, which is the value of a solution considered to be neither acid nor alkaline i.e. neutral. In pure water, the concentration of hydrogen ions is equal to 10¯ ; when an acid is added to pure water, the hydrogen ion concentration increases above this level. The pH level of the solution in which the seeds are germinating affects the availability of
Titrating Sodium hydroxide with an unknown molarity, against hydrochloric acid to find its' molarity.
Titrating Sodium hydroxide with an unknown molarity, against hydrochloric acid to find its' molarity. P2aP2aAim: - To find out the concentration of sulphuric (VI) acid by performing a titration with sodium carbonate solution. Introduction Sodium carbonate is an alkali, meaning that it has basic properties and has a pH that is greater than pH7, which is neutral. All pHs that are lower than pH7 are considered to be acidic. The pH scale runs from pH1, to pH14. A base is a solution/substance, which receives hydrogen ions (H+, also referred to as a proton) willingly, whereas acids are proton donators, this means that they give hydrogen ions off when in solution. The more basic something is, the more hydrogen ions it can receive and the more acidic something is, the more hydrogen ions it gives out, pH is a measure of this. In this particular titration, we will be neutralising the acid (H2SO4) with an alkali (Na2CO3), which is a carbonate. When an acid and a carbonate are reacted, the resulting products are a salt, carbon dioxide and water. These equations show what reactants and products are involved in this experiment: excellent shows you are thinking coherently about the problem evidence for P11a H2SO4 (?q) + Na2CO3 (?q) --> Na2SO4 (?q) + H2O (?) + CO3 (g) mole + 1 mole --> 1 mole + 1 mole + 1 mole Hydrochloric acid (?q) + Sodium
Reactivity Series Investigation
Experiment on Metals Aim-To find out which of these metals will be most reactive with hydrochloric acid,and plan an investigation to test it out.The Metals given:Calcium,Aluminium,Iron,Magnesium and Zinc. Prediction-I predict that the metal will be the most reactive with hydrocholoric acid is calcium because calcium is in Group 2 which is the alkaline earth metals in the periodic table and because calcium is at the extreme left side of the periodic table and as you go across a period,the element change from reactive metals on the left to non reactive metals on the right.On the extreme right of the periodic table is the noble gases.Also calcium is Group 2 which is the alkaline earth metals and they are part of the reactive metals which is Group 1 and 2.Also out of all of the metals given calcium reacts more faster with air and creates a sparkling sight and can damage your eyes creating calcium oxide in word equation it is Calcium+Oxygen equals calcium oxide.In chemical equation it is 4Ca +O2 equals 2 Ca2o.Calcium also reacts more than zinc,aluminum,iron and magnesium with water and much more violent and quicker creating vapour and moves much faster than the other metal and creates a vigrous sizzling sound and fizzing in water and dissloves much faster than the other metals. The alkaline metals get more reactive as you go down the group and
whether the strength of Hydrochloric acid will affect the speed of the rate of reaction when reacting with Magnesium Ribbon.
I want to find out whether the strength of Hydrochloric acid will affect the speed of the rate of reaction when reacting with Magnesium Ribbon. Variables There are two important independent variables in my investigation the first of which is the concentration of the Hydrochloric Acid used during the investigation. The concentration of the acid will partly determine how fast the reaction takes place, if we put some of the magnesium ribbon into the HCL at 2molar then it might have simply dissolved within a few seconds and then I would not have had time to record down any decent enough results to plot a graph with. The other important independent variable that will affect the speed of the rate of reaction is the length of magnesium ribbon. We need to put enough Mg Ribbon into the HCL so that it doesn't run out straight away but also so that the experiment stops by itself once the gas syringe has filled up. The reasons for choosing these two independent variables are that it would be too hard to try and find a catalyst for this experiment; a catalyst is a substance that increases the rate of a chemical reaction without being consumed in the reaction. Finding a catalyst for this particular experiment could take months never mind the amount of time we have been given for our experiment. The independent variable that I will change is going to be the hydrochloric acid, we will
What effects the rate of a reaction
Factors affecting the rate of a reaction Possible independent variables - these are the factors that could be changed: - Surface area: volume of the magnesium - Temperature - Time: How long the magnesium piece is left in - Concentration of solution - Mass of magnesium All of these factors would have some kind of effect on the rate of reaction: We would expect that if the temperature was increased, then the rate of the reaction would occur quicker. When a mixture of substances is heated, the particles move faster. Since the particles are moving faster, they will travel a greater distance in a given time and so will be involved in collisions. Also, because the particles are moving faster, a larger proportion of the collision will exceed the activation energy and so the rate of reaction increases. The greater the surface area, gives a greater area for collisions to take place. Therefore this also increases the rate of a reaction. How long the magnesium was left in the solution would also affect the experiment, as we would expect that with a longer duration, there would be more time for the reaction to occur. As time as the changing factor it would be very difficult to get an accurate measurement of the rate of reaction. I do believe that mass wouldn't be a good independent variable as it would be hard to increase the mass of the magnesium without increasing the
