Methods of Removal of Hardness in Water
Methods of Removal of Hardness in Water Removal of Temporary Hardness By boiling the hard water Temporary hardness in water can be easily removed by boiling. On boiling, calcium/magnesium bicarbonate decomposes to give calcium/magnesium carbonate, which is insoluble in water. Therefore, it precipitates out. By the addition of slaked lime (Clark's process) In Clark's process, slaked lime, Ca(OH)2 is added to temporary hard water. Insoluble calcium carbonate precipitate out and no longer produce hardness. The methods used to remove permanent hardness given in the next section can also be employed to remove the temporary hardness. However, the above methods cannot be used to remove the permanent hardness. Methods to Remove Permanent Hardness By the addition of washing soda (sodium carbonate) Calcium and magnesium ions present in hard water react with sodium carbonate to produce insoluble carbonates. The water now contains soluble and harmless sodium salts. Calgon process Calgon is a trade name of a complex salt, sodium hexametaphosphate (NaPO3)6. It is used for softening hard water. Calgon ionizes to give a complex anion: The addition of Calgon to hard water causes the calcium and magnesium ions of hard water to displace sodium ions from the anion of Calgon. This results in the removal of calcium and magnesium ions from hard water in the form of a complex with
Chemistry coursework - Fuels
Planning Aim In this investigation I will have to find out which of the alcohol fuels: methanol, ethanol, propanol and butanol, is the best. The 'best' one will be the one which creates the most energy whilst burning. Introduction and prediction A fuel is a substance burned for heat or power. The best type of fuel is one that: can be transported safely without the worry of it catching on fire, gives out a lot of heat for a certain mass, does not cost very much, lights quickly, burns slowly, is safe to use and does not give off any form of polluting gases. When burning alcohols, as I am going to do in this investigation, the reaction is exothermic as heat is given out. Breaking the bonds of the original alcohol by burning requires energy-it is endothermic, making the bonds of the new products of burning the alcohol ie carbon dioxide and water gives out energy-it is exothermic. I predict that Butanol will require the most energy as it has the most bonds holding the carbon, oxygen and hydrogen atoms together. Propanol will require the second largest amount of energy, Ethanol the third and Methanol the least amount of energy to break these bonds. Methanol CH3OH Ethanol C2H5OH Propanol C3H7OH Butanol C4H9OH Pentanol C5H10OH Therefore I predict that Methanol will be the 'best' fuel, followed by Ethanol, then Propanol and the worst fuel will be Butanol. Apparatus
An experiment to investigate the rate of reaction between
An experiment to investigate the rate of reaction between marble chips and hydrochloric acid The aim of this experiment is to find the factors that affect the rate of reaction between calcium carbonate and hydrochloric acid. The equation for this reaction is shown below. Calcium Carbonate + Hydrochloric Acid --> Calcium Chloride + Water + Carbon Dioxide The variables that I believe are most likely to have an effect in my experiment are: . Temperature 2. Concentration (of hydrochloric acid) 3. Surface area (of marble chips) 4. A catalyst However instead of investigating all four variables, I have chosen to investigate how different concentrations of hydrochloric acid affect the rate of reaction between marble chips and hydrochloric acid. My prediction for this experiment is that as the concentration of hydrochloric acid increases, the rate of reaction will also increase in direct proportion. My reasons behind the above prediction are that so a reaction can take place, the particles of the substances reacting have to collide. If they collide with enough energy then they will have enough energy in order for them to react. If the concentration of hydrochloric acid is increased it will, in turn, increase the number of particles in a given volume, in contact with the marble chips. This will lead to more collision, so the rate of reaction will increase also. Doubling the
Reaction of Alcohol Lab
Name: Teacher: Date: October 16, 2010 Purpose: To test the theories of how the molecular structure of an organic molecule affects its properties and determine the different isomers of butanol through comparison of their reactions with distilled water, Lucas Reagent and Potassium Permanganate. Materials: - Unknown butanol isomers A, B, C, D - Pipettes - Distilled water - Lucas Reagent (conc. HCl + ZnCl2) - Potassium Permanganate (KMnO4) - pH probe/ pH paper - Test tubes (4) - Test tube rack - Rubber stoppers (4) - Goggles - 10-mL measuring cylinder - 25-mL measuring cylinder Flowchart: Prediction: Distilled Water Lucas Reagent Distilled Water & KMnO4 n-butanol Lowest solubility; mixture should be heterogeneous Takes much longer than 5min to turn cloudy Colour changes; pH should turn acidic, since it becomes an aldehyde and then a carboxylic acid i-butanol 2nd lowest solubility; mixture should be heterogeneous Takes much longer than 5min to turn cloudy Colour changes; pH should turn acidic; since it becomes an aldehyde and then a carboxylic acid s-butanol 2nd highest solubility; mixture should be heterogeneous Turns cloudy after ~5min Colour changes; pH should remain neutral, since it becomes a ketone t-butanol Highest solubility; mixture should be homogeneous Forms precipitate and turns cloudy immediately No colour change, since it
Heat Energy Experiment Aim: To measure the heat energy released in a burning fuel.
Heat Energy Experiment Aim: To measure the heat energy released in a burning fuel. Diagram: Method: * The apparatus was set as shown in the diagram. * 20ml of water were measured. * The initial temperature of the water was measured as well as the distance from the tile to the bottom of the test tube. * The mass of the watch glass with and without the fuel was measured. * The fuel was lighted with a lighted splint and left to burn until it ends. * The mass of the watch glass was then re-measured. * The final temperature of the water was recorded. For safety reasons a heat-proof tile was placed under the watch glass and goggles were used. The fuel was lighted with a splint and not the Bunsen burner, and the experiment area was completely clear for space. For accuracy, the maximum temperature of the water was measured. The fuel was not left for a long time as the water would evaporate and the bottom of the test tube was cleaned in order not to interfere with the heating process. To make it a fair test, the time taken of different fuels to burn could be measured. If this happened, the apparatus should be properly washed, everything re-weighed and re-measured, and the thermometer left to cool. Results: (Averages) Ethanol Fire Lighter Distance from test tube to tile (cm) 2.5 cm 2.5 cm Initial temperature (ºC) 4.5 ºC 7.5 ºC Final Temperature
What an ester is, how it is made, examples of esters, animal testing issues and ethics.
Using esters in cosmetics Esters are used regularly and are in many of our everyday cosmetic products, drinks, foods etc. The most They provide an artificial smell or flavouring and provide a wide range of smells and tastes (depending on the type of carboxylic acid used). A lot of people would not have heard about esters, thus, they would also not know many important ingredients in the cosmetics they buy. Many products test on animals which many people would find unethical. We were investing at school esters and how to make an ester, also, we looked further into the unknown ingredients we may find in our products and how many people would but things and not know if it was animal tested or not . In this essay I will write about: what an ester is, how it is made (the experiment I carried out to make an ester), examples of esters, animal testing issues and ethics, a questionnaire I carried out to see what people knew about the cosmetics they own, what an emollient is and I will write about a fair test that I can carry out to see if the cosmetics are right about the information they give about their cosmetics- to the general public. (http://www.myhealthguardian.com/wp-content/uploads/2009/10/cosmetics-070126-1-full.jpg ) So what are cosmetics? The US Food and Drug Administration believe that cosmetics are "articles intended to be rubbed, poured, sprinkled, or sprayed on,
Chemistry - Reactivity Serires report
Name: Daniel Shih Form: 5D Teacher: Dr. Aravind School: Kiangsu-Chekiang College International Section Date: 12th January 2007 Index I Introduction Planning - Aims, Variables, Fair Test, Prediction, Hypothesis Planning - Apparatus, Procedure, Measurement, Safety rules Obtaining - Observation, Results Observation Analyse - Table 1 and Table 2 Analyse - Table 3 and Table 4 Analyse - Table 5 Evaluation, Conclusion Resources Introduction: What is the reactivity of metal? The reactivity of metal was the rate of metal which it would be reacting with each others. The higher the reactivity was, they could have replaced the more other kind of metal in the metal solutions. The metal who has the highest reactivity now is Potassium (K). What is metal? Metal is elements, there were more than 50 kinds of metals scientists have discovered today. The metal have different reactivity rate. Just like the Food Chain, higher reactivity metal can replace the lower reactivity metal when the reactions have occurs. How the reactions can occurs? The reaction occurs when a metal have replaced the other kind of metal in a solution, as example, When Magnesium have be drop into a Iron Sulphate solution, reaction occurs. Magnesium will take over irons placed, and formed Magnesium Sulphate solution, and left with Iron crystal. The Word equation will be: Magnesium + Iron Sulphate
Growing Alum Crystals
Abstract The aim of this experiment was to determine the effect temperature on the alum crystal growth by altering the dependant variables ranging from an incubator, a freezer and a cupboard in room temperature for ten days. It was hypothesized that the crystal in the incubator would grow the biggest because the solvent will evaporate faster resulting in the crystals to grow faster. After the experiment was conducted, it was concluded that the crystal in the cupboard grew and weighed the largest. There are certain explanations as to why the crystal in the incubator should have grown the largest and other reasons why the experiment wasn't conducted successfully; mainly because the crystals were exposed to the allocated environment for a very short period of time. Introduction The chemical formula for potassium alum is KAl(SO4)2.12H20 signifying that the reaction is composed of potassium, aluminium, sulphate and water (Barthelmy D, 2005). Potassium alum is the most important and most used alum. It is colourless, has a density of 1.76, a transparent diaphaneity, non fluorescent, vitreous and usually forms a large octahedral formation. Potassium alum has a pH of between 2.3 to 2.8 which makes it an acidic (Microsoft Student, 2007) Alum is a cost efficient coagulant used in the treatment of water and wastewater treatment for domestic and industrial purposes. It can remove
First aid project - treating common injuries in the laboratory.
First aid project Common injuries in laboratories and the action to take: Heat burns and scalds- 1. Lay down the injured person, making sure the burn/ scald does not come into contact with the ground. 2. Cool down the burn/scald with cold water (do this for around 10 minutes) 3. Remove clothing, rings, belts and anything around the burn, as the burn will start to swell 4. Cover the burn with a dressing. Make sure it is sterile so the burn does not get infected. 5. Call the emergency service, and whilst waiting make sure the casualty is breathing properly and monitor their pulse regularly. Do not try to treat the burn/scald with any creams or oils Chemical burns- 1. Take the injured person away from place where the accident happened to reduce potential risk to yourself 2. Remove any clothing that has chemical on it and take off anything else which has come into contact with the chemical 3. Wash the chemical burn with cold water for at least 20 minutes 4.Apply a cold, wet cloth to the burn 5. After all of the chemical is washed away and the burn is not painful, cover the it with a sterile dressing. Injury from breathing in fumes or swallowing chemicals- 1. Make sure the casualty is able to breathe and, if necessary, clear their airway. Check their pulse and begin CPR if necessary, but do not give mouth to mouth so as to not put yourself at risk 2. Do not make the
Burning Fuels Coursework
0/10/06 Chemistry Coursework In my chemistry coursework I will be investigating the amount of thermal energy different fuels will provide when burnt. My project brief is to "Examine alternative fuels for a power station that has until recently burnt coal. The fuel that gives the best value for money ratio will be the next one used in the power station." The costs of the fuels are: Fuel Cost in £ per kg. Methanol 5.10 Ethanol 7.20 Propan-1-ol 7.10 Butan-1-ol 6.20 Pentan-1-ol 16.90 Bond Energy Calculations The bond energy of a molecule is the energy released after it has reached the 'barrier' - the input energy needed for the bonds to break. Different bonds release different amounts of energy. The bond energy of all the fuels listed above needs to be calculated so that I can work out how much heat energy each fuel should theoretically produce when burnt, and then apply it to a formula to work out how cost effective that particular fuel is. Working out KJ/£ Methanol 6.81 KJ/g £5.10 per kg =0.00510 per gram 6.81 0.00510 = 3,296.08 KJ/£ Ethanol 22.51 KJ/g £7.20 per kg =0.00720 per gram 22.51 0.00720 = 3,126.39 KJ/£ Propan-1-ol 25.57 KJ/g £7.10 per kg =0.00710 per gram 25.57 0.00710 = 3601.41 KJ/£ Butan-1-ol 27.10 KJ/g £6.20 per kg =0.00620 per gram 27.10 0.00620 = 4,370.97 KJ/£ From my KJ/£ equations the
