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
oxidation of ethanol
The Oxidation of Ethanol Safety The chemicals used in the experiment were- > Ethanol > Ethanal > Ethanoic Acid > Sodium Carbonate > Sodium Dichromate > Sulphuric Acid > Universal Indicator The above chemicals did have some hazards when in the context of this experiment. Due to these hazards, to protect from things like the Na2Cr2O7, which stains, I wore protective glasses to prevent things from entering my eyes. Below are the hazards. Ethanol - Highly flammable above 13°C causing a narcotic effect if inhalation of the vapour occurs. Toxic Dangerous with › Oxidising Agents - incontrollable reactions take place › Bromine › Mercury (??) › Silver Nitrate › Platinum › Potassium Ethanal - Extremely flammable above -27°C Harmful - risk of irreversible effects Dangerous with sulphuric acid - evident polymerisation reaction May occur Ethanoic Acid - Corrosive › Severe Burns › Flammable above 40°C › Vapour irritating to the respiratory system Brady's Reagent - Irritant to › Eyes › Skin › Respiratory System Sodium Dichromate - Very Toxic › Cause cancer if inhaled › Harmful if swallowed › Harmful if in contact with skin › Ulceration may occur on damaged skin - Sensitisation by skin contact Danger to environment - Very to toxic to aquatic environment may Cause long-term adverse effects Sulphuric Acid -
Investigating the rate of reaction between magnesium and hydrochloric acid
I have done some preliminary work to investigate the best way of investigating the reaction between magnesium and hydrochloric acid. Magnesium + hydrochloric acid magnesium chloride + hydrogen Preliminary work 1 The first method I used is shown in the diagram above, which shows the way the apparatus is set out. This experiment measures how long it takes for the magnesium and hydrochloric acid to react to form magnesium chloride+ hydrogen. The magnesium and hydrocloric acid in the test tube react to make hydrogen,which travels through the delivery tube and into the measuring cylinder and measures how much hydrogen is collected as the hydrogen forces the water out of the measuring cylinder. This can be used to measure the rate of the reaction and I am trying to collect 50cm3 of hydrogen. In this experiment I have used three different types of magnesium (a strip of magnesium, a strip of magnesium cut up into three pieces and magnesium turnings) all weighing at 0.05g, also I have used 25cm3 of hydrochloric acid. The equipment I have used is a stop clock, bowl of water, measuring cylinder, bung, delivery tube and a test tube. Here are the results:- Size of magnesium (0.05g) Time taken to collect 50cm3 (seconds) Stip of magnesuim 358 Magnesium cut up into three pieces 314 As you can see, as the pieces of magnesium gets smaller, the faster the rate of reaction
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,
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
Should food additives be banned
Should food additives be banned? Contents: s Introduction Page 1 Why use additives? Page 2 Benefits and risks of food additives Page3 E-numbers and why are they used? Page 4 Different types of food additives Page 5 The two main food colourings? Page 6 Health risks of food colourings Page 6 Case Study; No more blue smarties! Page 7 For and against for food additives Page 7 Hyperactivity in children Page 8 Conclusion Page 9 Bibliography Page 9 Why use additives? People use additives in food to make the food look more attractive and colourful also to make customers' buy the food. Additives are used so the foods have a high quality. Many people enjoy making cakes, breads and ice-creams at home, however most of today's food is bought from shops and supermarkets. In some products, they are so essential that additives are used even in certain organic foods. Many foods can be made at home without the addition of gelling agents.Thickners or stabilizers. Food cooked often produced in small
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
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
Nutrients in a Balanced Diet
Nutrients in a Balanced Diet The 6 main nutrients are carbohydrates, fibre, vitamins, fats, protein and iron. Foods like cereals, bread, rice, pasta are good sources of carbohydrates and they give us the energy we need to do daily activities. If your daily calorie intake is 2,000 calories this amounts to at least 250 grams of carbohydrate per day. 1,500 calories a day equates to 188 grams of carbohydrate per day. Dried peas and beans like lentils, chickpeas and kidney beans are the best sources of fibre and is important for keeping the digestive tract working smoothly. Since we do not digest it, the fibre in food passes into the intestine and absorbs water. In the UK we eat on average 12g fibre per day, but new guidelines suggest this should rise to 18g, of both kinds of fibre. You get vitamins by eating foods from different food groups like pork, poultry, eggs and fish are the best sources of vitamin The vitamins work together to help your body use the energy you get from food. Some vitamins are also important in helping the body use protein from the diet to build new cells and tissues. The suggested daily requirements for men, women are shown in the Table below. Vitamin Men Women A 0.7mg 0.6mg B1 .0mg 0.8mg B2 .3mg .1mg Nicin 9mg 5mg B6 .4mg .2mg Pantothenic acid 5mg 5mg Folic acid 0.2mg 0.2mg Biotin 0.03mg 0.1mg B12 0.002mg 0.002mg C
