To see how the concentration of acid, reacting with potassium carbonate, affects the rate of reaction
Aim: To see how the concentration of acid, reacting with potassium carbonate, affects the rate of reaction. Intro: This is the reaction I am using in my coursework: 2HCl + K2CO3 CO2 + 2KCL + H2O In order for substances to react together the particles in the substances must collide with each other and the collision must have enough energy. If there isn't enough energy, no reaction occurs. If there are lots of successful collisions then a lot of CO2 will be produced. The rate of a reaction depends on how many successful collisions there are in a given unit of time. A reaction can be made to go slower or faster by changing the concentration of a reactant. Acid particle Water molecule Potassium carbonate tablet 1 2 In dilute acid, there are not so many acid particles (see diagram 1). This means there is not much chance of acid particles hitting a potassium carbonate particle. In a more concentrated solution of acid, there are more acid particles (see diagram 2). There is now more chance of a successful collision occurring. Concentration is how much of a substance there is in a certain volume and is measured in Moles per litre of solution (M). The concentration of a solution is the amount of solute, in grams or Moles that is dissolved in a litre of solution. That is what my coursework is mainly about. I predict that on my
Chemistry Investigation on neutralisation reaction Plan Neutralisation is the reaction that occurs when an acid has its acidity, that is its hydrogen ions removed by, another chemical containing OH- hydroxide ions. Chemicals that can cancel out an acid in this way are: bases (metal oxides or hydroxides), alkalis (bases that dissolve), metals (e.g. magnesium) or metal carbonates (e.g. marble chips) All of these have a similar way of removing the hydrogen from the acids (they swap it or their metal atoms) but the reactions are quite different. They will all get quite hot if the acid is strong enough, but only the last two will make bubbles. Metals form hydrogen gas, carbonates make carbon dioxide. All of them will leave a neutral chemical after the reaction has finished, if all the acid has been used up. Titration is a technique used to calculate the concentrations or amounts of substances. In an acid base titration you may have an acid that you don't know the concentration of, and a base whose concentration you do know. The technique is to measure out accurately a volume of the alkali of unknown concentration into a flask, and fill up a burette with the acid. Add some indicator solution to the acid in the flask, so that when all the acid has reacted with the base, there will be a colour change. The burette is graduated. You then open the tap on the burette and let the acid
Analysis The results of my investigation show that the larger the amount of hydrogen in the acid, the smaller the amount of acid needed to neutralise the alkali. This is because when an acid is added to an alkali each hydrogen ion in the acid joins an hydroxide ion in the alkali to form neutral water. Hydrogen ion from Hydroxide ion from Neutral water acid alkali The solution only becomes neutral if the amount of hydrogen ions and the amount of hydroxide ions are equal. If there were more hydrogen ions than hydroxide ions then once every hydroxide ion joined with 1 hydrogen ion there would be hydrogen ions left meaning the solution would become acidic. If there were more hydroxide ions than hydrogen ions then once every hydrogen ion joined with 1 hydroxide ion there would be hydroxide ions left meaning the solution would become alkaline. When an acid contains more hydrogen then there are a greater number of hydrogen ions per ml than in an acid containing less hydrogen so it will be stronger. For example in sulphuric acid (H2SO4) there would be more hydrogen ions than in the same amount of hydrochloric acid (HCl), twice as many because there are twice as many in the formula. The alkali in my experiment remained the same throughout (NaOH)
Oserving the properties of water. Place a drop of water on a smooth plastic sheet or on the bench. Look at it closely from the side.
SOME OBSERAVATION ON WATER Experiment # 1: Place a drop of water on a smooth plastic sheet or on the bench. Look at it closely from the side. Draw the outline of the drop. How are the molecules held in their place? * The drop of water and the drop of detergent have a different thickness, because the molecules are held differently. The drop of water, in fact, has a higher thickness. The molecules are closed to each other and it's possible to notice the surface that behaves as an elastic membrane that surrounds and compresses the underlying liquid. There is a force of cohesion that determines the surface tension. Experiment #2: Fill a clean 250 ml. beaker with water to about 1 cm. below the top. Carefully float a small filter paper on the surface. Carefully drop a needle, exactly horizontal, on the paper. Wait until the paper becomes soaked and sinks. Observe the needle carefully. After you have observed it, add one drop of detergent with a glass or plastic rod. * the piece of paper floats on the water and then it sinks because it get too wet. the needle continues to float, although its specific gravity is higher than the water's one, maybe because the water surface forms a kind of membrane ( see: ex.#1), impenetrable by small objects (as the needle). Adding the detergent, the needle has sunk because
Planning My aim for this experiment is to investigate the solubility of salt Prediction Like Hot tea can dissolve more sugar than iced tea, and warm water dissolves less oxygen than cold water. The maximum amount of any solute that can dissolve in a given amount of solvent is called its solubility, and this depends on temperature. The solubility's of gases always decreases with increasing temperature. For liquids and solids, solubility's generally increase with increasing temperature, as is the case with sugar in tea. This should work the same way with hot water and salt the hotter the water the more salt will dissolve. Variables For this experiment I would expect to have dependent variables, which are temperature of water, amount of salt before and after and time for each experiment. Fixed variables, the amount of water being heated, the amount of salt at the beginning and the time for each experiment. Scientific Knowledge Salts contain positive and negative ions, which are held together by the strong force of attraction between particles with opposite charges. When one of these solids dissolves in water, the ions that form the solid are released into solution, where they become associated with the polar solvent molecules. H2O NaCl(s) Na+(aq) + Cl-(aq) We can generally assume that salts dissociate into their ions when they dissolve in water. Ionic
The aim of the experiments was to test food samples to see which food group the sample belongs to. I also did tests to determine what type of carbohydrate an unknown carbohydrate was.
Food Tests Write-Up The aim of the experiments was to test food samples to see which food group the sample belongs to. I also did tests to determine what type of carbohydrate an unknown carbohydrate was. I did the biuret test to determine if a sample was a protein, the benedict's test to determine if a sample was a reducing sugar, the emulsion test to determine if the sample was a fat and used hydrochloric acid to split a non-reducing sugar into its monomers and then used the benedict's test to check that the monomers are reducing sugars. I predict that the sample containing protein will turn purple, benedict's reagent will turn reducing sugars to a brick red colour, the emulsion test will produce a white precipitate and starch will turn iodine black/brown. Apparatus Lists Biuret test * Biuret Reagent * Test Tube * Pipette * Protein Sample (Egg Albumin) Benedict's test for reducing sugars * Benedict's reagent * Reducing Sugar Sample * Test tubes * Water Bath or heating apparatus (Bunsen burner, tripod, gauze, valve and heat-proof mat) * Pipettes Benedict's Test for non-reducing sugars * Benedict's reagent * Non-reducing sugar sample e.g. sucrose * Test tubes * Water bath or heating apparatus * Pipettes * Hydrochloric Acid * Alkali powder (sodium hydrogen carbonate) Starch Test * Starch Sample * Iodine * Tray * Pipette Emulsion Test * Ethanol *
ANALYSIS OF ASPIRIN BY BACK TITRATION HNC APPLIED SCIENCE ANGELA COFRE 4 DECEMBER 2006 Analysis of Aspirin by Back Titration SUMMARY The purpose of the experiment was to determine the amount of aspirin in a tablet and to compare this with the amount specified on the label. The amount of aspirin calculated from the results obtained from titrimetric analysis to be 317 mg. The stated dose of the tablets on the manufactures label was 300 mg KEY WORDS Aspirin Back Titration Manufactures Labelling AIMS AND OBJECTIVES Objectives The objectives of this experiment are to determine the amount aspirin in a tablet and to compare this with the amount specified on the label. This was carried out using back titration. Aims The aims of the experiment were as follows: * Calculate the number of moles of HCL used in the reaction. * To determine the amount aspirin in an aspirin tablet and compare it with the amount specified on the label. * Calculate the number of moles of NaOH taken for hydrolysis. * Calculate the number of moles of NaOH used in hydrolysis. * Calculate the number of moles of aspirin. INTRODUCTION Aspirin is an acid and can be determined analytically by the method of back titration. However aspirin is not soluble in water so cannot be titrated directly with an alkali. So the aspirin is reacted with an excess of sodium hydroxide, which produces a water
To determine the concentration of a calcium hydroxide solution Aim: Our aim is to use a standard solution of hydrochloric acid to find the concentration of limewater (Calcium hydroxide). Indicator: Choosing a suitable indicator is important, I had to be extremely careful with this, I have chosen to use the indicator methyl orange. The limewater used will be a relatively weak base so it will be appropriate for using methyl orange and the acid that I am using is strong. Safety notes: * Safety goggles must be worn at all times whilst carrying out this experiment. Hydrochloric acid: * Contact with the eyes or skin can cause serious permanent damage. When in contact with the eyes immediately rinse the eye with plenty of water and call for medical help. * If in contact with skin rinse thoroughly and if redness on skin occurs call for medical help. Calcium hydroxide: * Powder may irritate the eyes. So if contact with eyes immediately rinsed the eyes with plenty of water, if irritation persists then calls for medical help. Since we are provided with a solution there is no particular danger. * When in contact with skin wash of with soap and water. Apparatus: * 250cm3 volumetric flask * 5cm3 graduated pipette * burette * pipette filler * white tile * clamp and stand * funnel * conical flask 250cm3 * 100cm3 beaker Balanced equation: Ca(OH)2 + 2HCl
Nickel and Nickel Alloys Abstract: Nickel in elemental form or alloyed with other metals and materials has made significant contributions to our present-day society and promises to continue to supply materials for an even more demanding future. Nickel is a versatile element and will alloy with most metals. Complete solid solubility exists between nickel and copper. Wide solubility ranges between iron, chromium, and nickel make possible many alloy combinations... Nickel has been used in alloys that date back to the dawn of civilization. Chemical analysis of artifacts has shown that weapons, tools, and coins contain nickel in varying amounts. Nickel in elemental form or alloyed with other metals and materials has made significant contributions to our present-day society and promises to continue to supply materials for an even more demanding future. Nickel is a versatile element and will alloy with most metals. Complete solid solubility exists between nickel and copper. Wide solubility ranges between iron, chromium, and nickel make possible many alloy combinations. Applications and Characteristics of Nickel Alloys Nickel and nickel alloys are used for a wide variety of applications, the majority of which involve corrosion resistance and/or heat resistance. Some of these include: * Aircraft gas turbines * Steam turbine power plants * Medical applications *
Back Titration Lab Report. In my experiment, I hoped to find the amount of calcium carbonate in some mineral limestone using the back titration method
Back Titration Lab Report Aim: Determining the percentage purity of calcium carbonate in a sample of limestone. Introduction: In my experiment, I hoped to find the amount of calcium carbonate in some mineral limestone using the back titration method The equation of the reaction is as follows: 2HCl + CaCO3 › CaCl2 + CO2 + H2O As not all the acid will be used up in the above reaction, I plan to obtain the amount of acid not used up and consequently the amount of calcium carbonate in the limestone, by titrating it with known sodium hydroxide solution. The equation of the reaction is as follows: HCl + NaOH › NaCl + H2O Apparatus: The equipment and reagents that I used are as follows: 250 cm3 beaker Electronic balance (± 0.01 g) 250 cm3 volumetric flask (± 0.2 cm3) 50.0 cm3 burette (± 0.05 cm3) 25. 0 cm3 pipette (± 0.1 cm3) 3 x conical flasks Clamp and retort stand 1.0 mol dm-3 hydrochloric acid, HCL 1.5 g of limestone phenolphthalein indicator 0.1 mol dm-3 Sodium hydroxide, NaOH Method: When I had all this, I started my investigation by weighing 1.5 g of limestone on the electric balance. After obtaining the weighed crystals I dissolved them with 1.0 mol dm-3 hydrochloric acid, in the beaker provided and stirred the mixture till bubbling stopped. I then added the solution into the volumetric flask and topped it with distilled water till