Combustion of Alcohols Investigation.
Combustion of Alcohols Investigation PLAN Aim: To find out how much energy is required to burn enough of the following alcohols: methanol, ethanol, propanol and pentanol, in order to heat a beaker of water by 40°. The combustion of an alcohol is an exothermic reaction, meaning that more energy is given off during the process than is being taken in. by knowing the individual bond energies for each bond, we can calculate what the energy values obtained from our investigation should aspire to to be accurate. Each bond (eg. C-H, where the '-' signifies a single bond, or O=O, where the '=' denotes a double bond), have different energies. They are as follows: Bond Bond energy (kJmol-1) C-H O=O C=O H-O C-C C-O 435 497 803 464 347 358 MOLECULE DIAGRAMS The following are the reactions which occur when each alcohol combusts. METHANOL: CH3OH + 11/2 O2 CO2 + 2H2O ETHANOL: CH3CH2OH + 3O2 2CO2 + 3H2O PROPANOL: CH3CH2CH2OH + 41/2 O2 3CO2 + 4H2O PENTANOL: CH3CH2CH2CH2CH2OH + 71/2 O2 5CO2 + 6H2O Given this knowledge we can calculate how much energy should be given out per mole of alcohol that is combusted. To do this we add up the bond energies for each bond that is either broken or made during the combustion process. We then simply subtract the total energy given out from the total energy used up. We should in theory obtain a negative number from this, as
Kinetic Theory of Matter Investigation
The Kinetic Theory of Matter The main points of the kinetic theory are: . All matter is made up of tiny, invisible, moving particles. 2. Particles of different substances have different sizes. 3. Smaller particles move faster than heavier ones at a given temperature. 4. As the temperature rises, the particles move faster because the particles have more kinetic energy. 5. In a solid, the particles are a very close together and they can only vibrate about fixed positions. 6. In a liquid, the particles are a little further apart. They have more energy and they can move around each other. 7. In a gas, the particles are far apart. They move rapidly and randomly in all the space they can find. This diagram shows the particles in the three states of matter: The Collision Theory of Chemical Reactions A chemical reaction cannot happen unless particles in the reacting substances collide with each other. There are three main conditions which must be presenting order for a reaction to occur: . The reactant particles must collide. 2. They must collide at the correct orientation (e.g. a head on collision is better than a glancing blow) 3. The must collide with a minimum amount of energy, (the activation energy) to allow the rearrangement of atoms; otherwise they simply bounce of each other. Changing the Rate of a Chemical Reaction The rate of reaction is only affected if
Osmosis Investigation
Osmosis Investigation Aim: To investigate the effect of varying concentration of a certain sugar solution on the amount of osmotic activity between the solution and a potato chip of a given size. Osmosis is defined as the net movement of water or any other solutions molecules from a region in which they are highly concentrated to a region in which they are less concentrated. This movement must take place across a partially permeable membrane such as a cell wall, which lets smaller molecules such as water through but does not allow bigger molecules to pass through. The molecules will continue to diffuse until the area in which the molecules are found reaches a state of equilibrium, meaning that the molecules are randomly distributed throughout an object, with no area having a higher or lower concentration than any other. Equipment list * Potato borer * Boiling tube rack * Boiling tubes * Paper towels * Weighing scales * Knife * Test tubes Prediction: For this particular investigation I think that the lower the concentration of the sugar solution in the test tube the larger the mass of the potato will be. This is because the water molecules pass from a high concentration, i.e. In the water itself, to a low concentration, i.e. In the potato chip. Therefore, the chips in higher water concentrations will have a larger mass than in higher sugar concentrations. When
What effect does Acid rain have on germination?
BIOLOGY COURSEWORK JENNY HODGSON 11A WHAT AFFECT DOES ACID RAIN HAVE ON GERMINATION? BACKGROUND KNOWLEDGE A seed is formed from the ovule of a flower as a result of fertilisation, and is then dispersed from the parent plant. If the seed lands in a suitable place, it will germinate. Germination is the growth of the embryo inside the seed, eventually growing into a mature plant. CONDITIONS NEEDED FOR GERMINATION OXYGEN - is used for aerobic respiration, which provides the energy for many chemical changes involved in the food reserves and making the new cytoplasm and cell walls of the growing seedling. TEMPERATURE - a rise in temperature speeds up most chemical reactions, including those taking place in living organisms. Germination, therefore occurs more rapidly at high temperatures (up to about 40 degrees centigrade). Above 45 degrees centigrade, the enzymes are denatured and the seedlings would be killed. Below 0-5 degrees centigrade, germination may not start at all. WATER - before the changes necessary for germination take place, the seed must absorb water. The water which reaches the embryo and cotyledons is used to: * Activate the enzymes in the seed * Help the conservation of starch to sugar, and proteins to amino acids * Transport the sugar in solution from the cotyledons to the growing regions WHAT HAPPENS DURING
Investigating how the length of a piece of wire affects resistance in a circuit.
Stephanie Wickers 1st July, 2003 Investigating how the length of a piece of wire affects resistance in a circuit Aim Resistance is measurement which describes how difficult or how easy it is for an electron to flow through a conductor in a circuit. Resistance is measured in Ohms. In this investigation I am going to be trying to find out and do further research into why resistance is affected by the length of a piece of wire. Research There are many factors effecting resistance in a circuit and the four main ones are Length, Temperature, Material, and Thickness. I have done research to find out how and why these factors affect resistance. If the length of the wire is increased then the resistance will also increase proportionally. This happens because the electron has further to travel in the circuit and therefore there is more chance of a collision between an atom and an electron. If the thickness of the wire increases then the resistance will decrease and if the thickness decreases the resistance will increase. This is because the increase in area will enable the electrons to move around more freely. This in turn will reduce the number of collisions between atoms and electrons and will lower the resistance as the flow of electrons is not interrupted as much by the atoms in the wire. If the wire is heated the atoms in the wire will vibrate due to the increase
In my investigation, I intend to find out what effect changing the concentration of sodium thiosulphate has on the rate of reaction between hydrochloric acid and sodium thiosulphate.
Plan of Experimental Procedures Preliminary Experiment Our teacher demonstrated the experiment for us. She drew an X on a piece of filter paper and placed it under a flask with sodium thiosulphate in it. She added the hydrochloric acid to the sodium thiosulphate. As the reaction occurred, the solution gradually became cloudy. We saw that the experiment ›visible. Introduction In my investigation, I intend to find out what effect changing the concentration of sodium thiosulphate has on the rate of reaction between hydrochloric acid and sodium thiosulphate. Na2S2O3 + 2HCl › S + SO2 + 2NaCl + H20 Independent Variable to be Investigated In the experiment, the independent variable will be the concentration of sodium thiosulphate. This is so I can see the effect of changing the concentration of sodium thiosulphate on the rate of reaction between the sodium thiosulphate and hydrochloric acid. Theory I predict that the rate of reaction will be directly proportional to the concentration of sodium thiosulphate solution. When the concentration is low, then there will be less chance of successful collisions between the hydrogen ions and the thiosulphate ions and so, will take longer to react. However, if the concentration of sodium thiosulphate is increased, there will be more chances for the hydrogen ions and thiosulphate ions to collide. Also, if the concentration
Benefits and implications of improving plant productivity.
Biology Coursework Skill I+J Benefits and implications of improving plant productivity Tamryn Renwick To increase plant productivity we can manipulate the environment, or more importantly we can improve the plants. There are many different ways that plant productivity can be improved, for example one option is to keep them in ideal, controlled environments such as glass houses and poly-tunnels. In these conditions, light intensity, temperature, CO2 concentration, moisture, etc are adjusted to suit a particular crop (2). But one major problem with this method of crop production is that costs are very high and there is not always a big enough profit. Another process that can be used to increase plant productivity is breeding programmes based on hybridisation. This process has many disadvantages though, such as, there is the transfer of few desirable genes also accompanied by the uncontrollable transfer of an additional 1000- 10 000 genes (1), the process takes 10-15 years to complete (1), and so has not been widely used. The most widely thought of way to improve plant productivity is genetic manipulation. Genetic manipulation (GM) was developed in the late 1970s (1) but has only been exploited to full in the last decade. It is a new and most important approach in increasing agricultural productivity, and is one of the fastest growing industries. Examples of genetically
Contributory factors to heart disease
Contributory factors to heart disease Diet is not the only factor that causes heart disease; lifestyle is also a very big factor. Smoking deprives the blood of oxygen and also narrows the blood vessels. Smoking dramatically increases the risk of developing heart disease, lung cancer and many other diseases. These diseases are not always fatal but can seriously affect your quality of life. If a person smokes they are more likely to die before they retire. " Smoking doubles your risk of dying from heart disease. Each year 35,000 British smokers die from heart disease." (Flora project for heart disease.) Taking more exercise will help prevent C.H.D. as it has a direct link to obesity. When a person is overweight the body and the heart have to work harder. A lack of exercise can increase the chances of C.H.D. the body takes in a certain amount of fat per day, and needs to burn it all off through exercise or else the body cant cope and the fat causes the arteries to build up and clot. Having excess weight on the body gives a higher blood pressure. "About 1 in 7 of us will have high blood pressure at some point." It is advised to have your blood pressure checked by your doctor. Especially if you are over 35 you should have your blood pressure checked every 3 years or so. There is no way to tell if you have high blood pressure or not as you don't feel any different.
The Electrolysis Of Copper Sulphate Solution Using Copper Electrodes.
The Electrolysis Of Copper Sulphate Solution Using Copper Electrodes Planning I did some preliminary work to see which current values, and for how long to time. The results of this are in the tables below: Electrode-1A Mass before (g) Mass after (g) Mass change (g) Anode 1.38 1.30 -0.08 Cathode 1.35 1.65 +0.30This was done for 10 minutes. The mass lost at the anode should equal the mass gained at the cathode, which this doesn't, it has a percentage inaccuracy of 0.22¸ .30x100= 73% which is very inaccurate, This may be due to the current being too high, so the copper does not all transfer properly, but lies on the bottom of the beaker, therefore a lower current must be used, as in the table below: Electrode-0.1A Mass before (g) Mass after (g) Mass change (g) Anode 1.42 1.35 -0.07 Cathode 1.16 1.21 +0.05This was also one for ten minutes, and shows much more accurate results, as the percentage inaccuracy is only 0.02¸ 0.07x100=29%, which is still inaccurate, but is a lot better . This could be due to the current value being to low, so I will take a range of 5 results from 0.1Amp to 1Amp at 0.2Amp intervals. Each electrolysis will last 10 minutes, and each will be repeated twice so that a more accurate average can be taken. Variables * Temperature of the electrolyte * The concentration of the electrolyte * The separation of he electrodes * The size of the
Investigate the effects of varying concentration of certain solutions on the amount of osmosis in a potato chip of a given size.
Osmosis in Plant Cells Plan: Aim To investigate the effects of varying concentration of certain solutions on the amount of osmosis in a potato chip of a given size. Prediction A definition of osmosis is: 'the movement of water molecules from an area of high water concentration to a low water concentration across a semi-permeable membrane' (Oxford dictionary 2000). In a high concentration of water the amount of solute (e.g. sugar) is low. These solutions are usually known as a dilute or weak solution. But in a low concentration of water the amount of solute (e.g. sugar) is high. These solutions are usually known as concentrated or strong solutions. When a weak solution and a strong solution are separated by a partially permeable membrane, the water will move from the area of high concentration to the area of low until both sides are equal. This is osmosis, and is shown in the diagram below. An Example of Osmosis Examples of osmosis can also be seen in living cells. Root hairs on plants take in water from the soil via osmosis. Water continuously moves along the cells of the root and up the xylem to the leaf. Water is moving to areas of lower water concentration all the time. This is shown in the diagram below. Example of Osmosis in a Root Hair Cell When a cell is placed in distilled water which is high water concentration water will move across the semi-
