Describing the structure and function of the major biological chemicals in the humans.
Describing the structure and function of the major biological chemicals in the humans Carbohydrates The main role of carbohydrates is to provide energy to the body. Carbohydrates are broken down into a form of sugar known as glucose. Glucose is carried to every cell in the body by the blood and can be used right away for energy. Glucose is also know as sugar. Carbohydrates imperical formula is Sugars are small molecules which are a product of carbohydrates. As the name implies, a carbohydrate is a molecule whose molecular formula can be expressed in terms of just carbon and water. For example, glucose has the formula C6(H2O)6 and sucrose (table sugar) has the formula C6(H2O)11. More complex carbohydrates such as starch and cellulose are polymers of glucose. Their formulas can be be expressed as Cn(H2O)n-1 in all carbohydrates this imperical formula will stay the same the structure will change making different types or carbohydrates such as Fructose,galactose,pentose and hexose these are known as isomers of carbo-hydrates.an isomer is something that has the same imperical formula but is structured differently to make other products. Mono-saccarides are things like fructose and galactose the term mono saccharides means that they only have one molecule. When two of these Mono-saccarides are 2 joined together and they form a di-saccaride such as lactose When 2 or more of
Is sulphuric acid dibasic?
Chemistry Planning Exercise Aim In this plan I shall demonstrate that sulphuric acid is dibasic. In order to do this affectively I will plan experiment using scientific techniques. The experiment will involve titration. I will then validate these experiments using calculations and appropriate chemistry knowledge. The reactants I have selected that will neutralise sulphuric acid are shown below in the equations: Reactants used in Titration and products obtained: H2SO4 (aq) + 2NaOH (aq) --> Na2SO4 (aq) + 2H2O (l) Background knowledge The acid (sulphuric acid) is identified by being paired with a hydrogen ion and a base (sodium hydroxide) is identified by being paired with a hydroxide group. Sodium Hydroxide neutralises the sulphuric acid to form salt and water. Sulphuric acid A dibasic acid has two hydrogen atoms in its molecule which can be ionised. Sulphuric acid is dibasic acid, because it contains two hydrogen atoms which ionise in aqueous solution to become 2H+ ions. The equation below shows an ionic equation for sulphuric acid. H2SO4 + 2H+ --> SO42- Sodium Hydroxide Sodium Hydroxide is used as a base. It is completely ionic, containing sodium ions and hydroxide ions. The hydroxide ions make sodium hydroxide a strong base which reacts with acid to form water and salt. The equations below shows a reaction between sodium hydroxide (base) with sulphuric acid
Assessed Practical Titration Write-up
Assessed Practical Titration Write-up Equation: Na2CO3 + H2SO4 --> Na2SO4 + CO2 + H2O One mol of Na2CO3 reacts with one mol of H2SO4. Results: The weight of my sodium carbonate crystals was 2.67g and the results of the titrations are as follows: Rough st 2nd 3rd 4th 5th 6th Initial Reading 00.00 00.50 00.00 00.00 00.00 00.00 00.20 Final Reading 26.45 26.45 26.05 27.00 25.85 25.90 26.10 Titration 26.45 25.95 26.05 27.00 25.85 25.90 25.90 pH slightly acidic neutral slightly acidic slightly acidic slightly alkali neutral neutral So the average of the closest three titration results are is: 25.95 + 25.90 + 25.90 / 3 = 25.92 The mass of Na2CO3 I used is 2.67g and the relative molecular mass of Na2CO3 is 106. So the number of mols of Na2CO3 I used was: 2.67 / 106 = 0.0251 mols in 250 cm3 So the concentration of the Na2CO3 solution was: 0.1004 mol dm-3. So in the 25cm3 of Na2CO3 solution I used, there were: 0.0251 / 10 = 0.00251 mols. The equation shows how 1 mol of Na2CO3 reacts with 1 mol of H2SO4, so 0.00251 mols of Na2CO3 reacts with 0.00251 mol of H2SO4. So in the 25.92 cm3 of acid I reacted with the Na2CO3 solution, there are 0.00251 mols. So the concentration of the acid is: ( 0.00251 / 25.92 ) x 1000 = 0.0968 mol dm-3 So the concentration of the acid is 0.0968 mol dm-3. Evaluation: There may have been some limiting
Chemistry (Salters) Open Book 2008
An ?-particle consists of 2 protons and 2 neutrons, identical to a helium-4 nucleus. During ?-decay, the atomic nucleus emits an ?-particle, which produces an element with 2 less protons and 2 less neutrons. In ß-decay, a neutron from the nucleus is converted into a proton and an electron. The electron is emitted from the atom as a ß-particle. As the electron has a very low and negligible mass, the new element formed has the same mass number as the parent atom. ß -decay creates an element with a proton number 1 higher than the parent atom. Nuclear fission reactions involve an atom absorbing an initial slow moving neutron, leading to the atom splitting into 2 different elements. The products formed are therefore dependable on the way in which the atom is split. This process differs from radioactive decay; which requires no initial energy input and produces a single new element, differing chemically from the parent atom by the subatomic particles emitted in the ? or ß-particle emission. Hydrogen and Helium are the two lightest elements in the periodic table. In stars, these nuclei are combined to form heavier elements in a process called nucleogenesis. Hydrogen and Helium atoms act as building blocks for the elements formed in nucleogenesis. Helium can be formed from the fusion of 4 Hydrogen nuclei: "As stars like the sun evolve, they use up most of their hydrogen and
risks of electricity
WHAT ARE THE RISKS FROM ELECTRICITY? Harm can be caused to any person when they are exposed to 'live parts' that are either touched directly or indirectly by means of some conducting object or material. Voltages over 50 volts AC or 120 volts DC are considered hazardous. Electricity can kill. Each year about 1000 accidents at work involving electric shocks or burns are reported to the Health and Safety Executive (HSE). Around 30 of these are fatal, most of them arising from contact with overhead or underground power cables. WHO IS MOST AT RISK FROM ELECTRICITY? Anyone can be exposed to the dangers of electricity while at work and everyone should be made aware of the dangers. Most electrical accidents occur because individuals: * are working on or near equipment which is thought to be dead but which is, in fact, live * misuse equipment or use electrical equipment which they know to be faulty. LEGAL DUTIES AND OBLIGATIONS AROUND ELECTRICITY As well as a moral duty on employers to protect employees and members of the public, General Health and Safety Legislation covers all employers and workplaces. In addition, specific duties and obligations are laid out in the following regulations: These regulations apply to all aspects of the use of electricity within the workplace from electrical supplies to the use of electrical equipment. They place a duty on employers,
Law of conservation of matter lab report.The chemical reaction used to research is: AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq)
Law of Conservation of matter Aim: To design and perform a quick experiment to prove the Law of Conservation of matter. Research question: Does the mass of the reactants before the experiment is same as the mass of the product formed? Does the mass of the matter stays conserved during a chemical reaction as stated by the Law of Conservation of Mass? Background theory: Law of Conservation of matter states that matter can neither be created nor be destroyed. According to this, there must be no loss in mass and particle of reactants after any physical or chemical reaction. The chemical reaction used to research is: AgNO3(aq) + NaCl(aq) › AgCl(s) + NaNO3(aq) Hypothesis: We hypothesis that the total mass of the reactants would be equal to the mass of products formed. This is because according to the Law of conservations of mass, there must be no loss in the mass of reactants in any reaction. Therefore, no loss in the total mass of reactants would prove the Law of Conservation of matter. Variables: The independent variable is the mass of the reactants. The dependent variable is the product produced and it's mass. The controlled variables are the same reactants, same volumes and types of the containers (beakers or graduated funnel, etc), same analytical balance to weigh and the same concentration of the reactants. Controlled Variables: The reactants that are
To draw and explain the shape of graphs of pH against volume of titrant for titrations involving monoprotic acids and bases.
Problem: To draw and explain the shape of graphs of pH against volume of titrant for titrations involving monoprotic acids and bases. The combinations we had were: 1) strong acid + strong base (titrant), 2) weak acid + strong base (titrant) and 3) weak base + strong acid (titrant). Data collection: Procedure: We had the different acids and bases in the beaker respectively in the burette and dropped the titrant into the beaker where we had a pH-meter and recorded the result. ) We had HCl in a 20 ml beaker and NaOH in a 50 ml burette and a few drops of BTB. 2) We had HAc in a 20 ml beaker and NaOH in a 50 ml burette and a few drops of BTB. 3) We had NH3 in a 20 ml beaker and HCl in a 50 ml burette and a few drops of BTB. The results were all rather similar; the graph curves were almost the same shape, even though the values differed from the one to another. *For more information, see attached graphs. ) 2) 3) ml pH 0 ,0 5 ,2 6 ,3 7 ,3 8 ,4 9 ,4 0 ,49 1 ,51 2 ,6 3 ,7 4 ,75 5 ,8 6 ,9 7 2,1 8 2,2 9 2,55 9,5 2,7 20 3,5 20,2 5,4 20,3 6,0 20,5 9,4 21 0,5 22 1,2 24 1,5 26 1,7 28 1,9 30 1,95 32 2,0 34 2,1 ml pH 0 2,6 5 4,0 5,5 4,1 6 4,1 7 4,2 8 4,3 9 4,4 0 4,5 1 4,55 2 4,6 3 4,7 4 4,8 5 4,95 6 5,1 7 5,2 8 5,3 9 5,6 9,5 5,9 20 6,3 20,3 6,8 20,7 0,4 21,1 0,6 21,5 1,0 22
Find the Ar of lithium.
Evaluation. Was my experiment suitable? My experiments enabled me to gain results, which then with the aid of calculations I could find the Ar of lithium. From this perspective you can say the experiment was suitable as I achieved this. Were my results what I expected? Looking at the results they do not match the expected Ar of lithium (6.9). Method 1, measuring the volume of hydrogen produced, gave the result of 19.76 (a factor of 12.86 out). Method 2, titrating the lithium hydroxide produced, gave the result of 8.65 (a factor of 1.75 out). So looking at these results not only we can see they are out, but one method is more inaccurate than the other. The titration is far more accurate than the collecting of gas. Comparing both methods, and recognising sources of error. Method1. Sources of error in the collection of gas practical were: When the lithium was weighed I had to place it on filter paper first to remove the oil from it. However I feel that not all of the oil was removed from the Li so perhaps this contributed extra mass which was not part of the Li itself. The scales themselves were awkward to use; when I placed some paper onto the scales and zeroed it (to weigh the Li onto) the mass kept fluctuating, so I was unsure as to how precise my weighing out was. These problems will have both contributed to a source of error- the mass of Li will have not been
Determination of the enthalpy change of neutralization
Chemistry Laboratory Report 4 Date: 27th October, 2008 Topic: Determination of the enthalpy change of neutralization Objective: To determine the enthalpy change of neutralization between different pairs of acid-base used (thermometric titration) Introduction Two methods are used to determine the concentration of sodium hydroxide solution and the enthalpy change of neutralization. First method: Measure the temperature change of the solution when different volume ratios of acid and base are mixed and reacted. Second method: Measure the temperature change of the solution upon each addition of a specified volume of acid to the base. Results > Method 1: Initial temperature of the solutions = 27.1 oC Volume of NaOH (cm3) 5.0 0.0 5.0 20.0 25.0 30.0 35.0 Volume of acid (cm3) 35.0 30.0 25.0 20.0 5.0 0.0 5.0 .00M Hydrochloric acid: Final Temperature (oC) 29.3 31.5 33.4 33.8 31.9 30.3 28.6 Temperature change (oC) 2.2 4.4 6.3 6.7 4.8 3.2 .5 .00M Ethanoic acid: Final Temperature (oC) 29.2 30.7 32.5 33.5 31.8 29.9 28.6 Temperature change (oC) 2.1 3.6 5.4 6.4 4.7 .8 .5 > Method 2: Initial temperature of the solutions = 27.0 oC .00M HCl Volume (cm3) Final Temp. (oC) ?T (oC) Volume (cm3) Final Temp. (oC) ?T (oC) 2.0 28.2 .2 22.0 34.0 7.0 4.0 29.3 2.3 24.0 34.4 7.4 6.0 30.1 3.1 26.0 34.2 7.2 8.0 30.9 3.9
Blood pH - There is a complex relationship between the pH levels and fundamental biochemical functions in the human body.
Introduction: There is a complex relationship between the pH levels and fundamental biochemical functions in the human body. pH is the measurement of acidity or alkalinity of a substance, in this instance blood. pH stands for 'potential Hydrogen'. The pH scale runs from 0 to 14 and is the indicator of the level of free protons (H+) in a system. At the lower end of the scale indicates a strong, complete acid that that is saturated with highly reactive free protons. At the higher end of the scale it indicates a strong, complete alkali with virtually no free protons and is saturated with highly reactive hydroxide ions (OH-). In the middle of this pH scale at 7 indicates that it is neutral, neither acid or alkaline. The pH scale is logarithmic so each number step up the scale is a tenfold increase. The human body functions at its best in a slight alkaline environment. The acid/alkaline balancing mechanisms are what is needed to for a healthy body chemistry. The blood pH in a healthy human body is kept within a very narrow range of 7.35 and 7.45. It is the lungs and the kidneys that are the most responsible organs in keeping blood pH at a reasonable level between 7.35 and 7.45.The kidneys through their complex filtration functions are able to cleanse the excess venous acids an remove them from the body via the urinary tract. The kidneys are responsible for releasing ammonia
