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

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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

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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

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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

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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

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