Various Factors in the Preparation and cooking of Fruit and Vegetables can change the Vitamin C content. Devise and experiment one of those factors.
Various Factors in the Preparation and cooking of Fruit and Vegetables can change the Vitamin C content. Devise and experiment one of those factors. Pilot Method . Use a syringe (or Measuring Cylinder for measuring equal amounts) and pour out 10ml of DCPIP (Solution used to detect Vit.C) into a small beaker. 2. Using a separate Syringe, draw up 10ml of solution 0.1% Vitamin C 3. Slowly add the Vit.C into the DCPIP solution beaker, swirling around a few times. (swirling helps solutions to mix) 4. Continue to add the Vit.C until DCPIP turns a permanent straw colour. 5. Note the amount of Vit.C it took to change the colour of the DCPIP. 6. Repeat steps 1-5 5 3 times and take an average. Pilot Results Strength of DCPIP X Volume = Volume of Vit.C x Strength )( x 10ml = 8.5ml x 0.1% )( = 6ml x 0.1% 10ml Strength of DCPIP = 0.06 Strength of DCPIP X Volume = Volume of Vit.C x Strength )( x 10ml = 6ml x 0.1% )( = 6ml x 0.1% 10ml Strength of DCPIP = 0.06 Strength of DCPIP X Volume = Volume of Vit.C x Strength )( x 10ml = 6ml x 0.1% )( = 6ml x 0.1% 10ml Strength of DCPIP = 0.06 Average Strength of DCPIP = 0.06 Method . Using a Syringe (or measuring cylinder) put 10ml of DCPIP into a small beaker. 2. Using a separate syringe, take up 10ml of Juice (Juices will change per experiment) 3. Slowly add the juice a little at a time until the DCPIP turns a
Acid-base Titration
S.6A Karen Kwok (8) 11th, September, 2002. Chemistry Laboratory Report Title: Acid-base Titration Date: 11th, September, 2002. Objective: (1) To determine the concentration of the unknown Sulphuric acid solution. (2) To learn how to use the pipette and burette skillfully. Result: The solution will change from yellow to orange when it is neutralized. 1st 2nd Final burette reading (cm3) 34.75 44.60 Initial burette reading (cm3) 9.55 19.25 Volume of sodium carbonate solution (cm3) 25.20 25.25 Calculation: The volumes of 0.0500M sodium carbonate required for neutralization are: 25.20 cm3, 25.25 cm3. Therefore the average volume of 0.0500 M sodium carbonate required for neutralization: = 25.20 + 25.25 2 cm3 =25.23 cm3 Na2CO3 (aq) + H2SO4 (aq) ›Na2SO4 (aq)+ CO2 (g)+H2O (l) 0.0500M ? M 25.00cm3 25.23cm3 No. of moles of sodium carbonate =Molarity of solution ×Volume of solution =0.0500 M ×0.0025 dm3 =0.000125mol According to the equation, mole of Na2CO3 required 1 mole of H2S04 for complete neutralization. ?No of moles of H2SO4 = 0.000125mol Concentration of H2SO4 solution = No. of moles of H2SO4 Volume of solution = 0.000125mol 0.002523dm3 =0.0495mol/dm3 Question: . In standardization of sulphuric acid solution with standard sodium sodium carbonate solution, methyl orange is
Acid Rain
Acid Rain What Causes Acid Rain? One of the main causes of acid rain is sulfur dioxide. Natural sources, which emit this gas, are Volcanoes, sea spray, rotting vegetation and plankton. However, the burning of fossil fuels, such as Coal and oil, are largely to be blamed for approximately half of the emissions of this gas in the world. When sulfur dioxide reaches the atmosphere, it oxidizes to first form a sulfate ion. It then Becomes sulfuric acid as it joins with hydrogen atoms in the air and falls back down to earth. Oxidation occurs the most in clouds and especially in heavily polluted air where other compounds such as ammonia and ozone help to catalyze the reaction, changing more sulfur dioxide to sulfuric acid. However, not all of the sulphur dioxide is changed to sulfuric acid. In fact, a substantial amount can float up into the atmosphere, move over to another area and return to earth unconverted. In the following pages I will show the effects of acid rain on: · Effect on Trees and Soils · Effect on Lakes and Aquatic Systems · Effect on Materials · Effect on Atmosphere · Effect on Architecture · Effect on Humans Effect on Trees and Soils One of the most serious impacts of acid precipitation is on forests and soils. Great damage is done when sulfuric acid falls onto the earth as rain. Nutrients present in the soils are washed away. Aluminium also present in the
The main purpose of this investigation is to test and analyse Mummion. By doing this we would hopefully be able to see what chemicals it contained.
Assignment 2.4 – A preservative for mummies 2.4.1 Introduction What is mummification? Mummification is an ancient Greek method which is intended to dehydrate the body. This would preserve the body. They believed that the body needed to be intact to serve as host for the soul. If the body was left to rot, it would destroy their soul. The process of mummification would entail the removal of the brain and other internal organs, each of these then mummified and then stored in jars. This then led on to the drying out process. The body would then be left outside to dry. After the body was completely dry. It would lead onto the wrapping of the body. The body would be wrapped. A final shroud piece would be placed on the mummy to keep all of the wrappings together. Mummion was added to the shroud to ‘give’ it all together. What is Mummion and what is it used for? Natron (Mummion) is a colourless salt found in various locations in the earth. Mummion is a dehydrated sodium carbonate mineral. Natron is known commonly to be used for mummification. Artists have also mixed it with minerals and oils to create the colour ‘Egyptian blue’. Also mixed with oils and minerals can produce soaps. Mummion can also be used as a cleaning product. What is the purpose of this investigation? The main purpose of this investigation is to test and analyse Mummion. By doing this we would
Activity Series of Metals Lab
| ________________ Activity Series Lab-2012 Introduction The types of changes that occur during these tests are chemical changes. Chemical changes will usually be tough to reverse, a new substance is created, heat is released, light is released, a solid is made (precipitate,) gas produced or the solution changes in colour. These chemical changes can be cause by decomposition, combustion, synthesis, single displacement or double displacement. The type of reaction that occurs during the tests is a single displacement reaction. This means that one element replaces another element in a compound. The general equation used for this reaction is A + BC -> B + AC. Like most other chemical changes single displacement reactions cannot be reversed. Depending on the activity series of metal some elements will be able to displace the other metal in the compound and some may not. Single Displacement reactions occur according to the Activity Series of Metal. Based upon experimental evidence reactive metals have been placed in order of reactivity known as the activity series of metal. The activity series is a chart with the most reactive metals on the top and the least reactive metals on the bottom. Lithium is on the top meaning it is the most reactive whereas gold is on the bottom being the least reactive. The order of the metals from most to least reactive corresponds with how easily
Explain the need for primary and secondary standards in analysis
Ardit Cenalia Unit 19 | M1 Explain the need for primary and secondary standards in analysis What is primary standard? A primary standard is a solution of which a concentrated is made from a primary standard. I.E. the substance available in a sufficiently pure from which requires no determination of concentration. A primary standard is one that can be determined to a high level of precision, and reliability. For instance, a typical acid-base titration can be done to determine the concentration of an unknown HCl solution. When titrated against NaOH there will be some uncertainty because of the lack of reliability of the NaOH concentration. For example sodium chloride is an example of a primary standard. This is because it can be obtained very pure. What is a secondary standard solution? A secondary standard solution is a solution which must be standardised first against a primary standard and afterwards it will be stable enough for titrimetric work. Potassium permanganate is an example of a secondary standard. It has to be standardised first, but then it can be used for quantitative analysis, A primary standard substance will not always be used in standardisation; this is because primary standard is a reagent which is very pure, representative of the number of moles the substance contains and easily weighed. For example sodium chloride is used as a primary
Plastics and Polymers
Plastics and Polymers Polymers were first made in the early twentieth century and were known as ‘plastics’. Polymers are constructed from much smaller molecules (monomers) that are joined together to form long chains (polymers). The economy and many industrial companies rely on polymers as a vital resource. An advantage of using polymers over natural materials is that polymers can be manufactured very specifically with varying degrees of stiffness, density, heat resistance and electrical conductivity. The study of natural polymers has also led to great advances in medicine and nutrition. Polymers have a great many uses: sheets and films, adhesives, paints and inks and also synthetic fibres and yarns. A very common polymer used widely in modern life is polyethylene (the simplest polymer). When it’s made into bags for supermarkets and other uses, it’s typically flexible and transparent. Its monomer (a single unit that is repeated) is Ethene (C2H4). It can be polymerised into polyethylene that generally contains around 105 Ethene monomers within its structure. The diagram shows the polymerisation of ethane into polyethene/polyethylene. PVC (polyvinylchloride) is another widely used plastic containing Carbon, Hydrogen and Chlorine. Molecules of vinyl chloride combine to make long chain molecules of PVC. This synthetic polymer is quite cheap and easy to mould and is
Outline different methods of separating substances.
Chromatography Chromatography- this is used for separating mixtures of coloured compounds, the mixtures that are used to be separate in chromatography includes liquids like dyes, ink and most commonly colouring agents in food. Chromatography is carried out on a single piece of paper is used where a small sample is placed at the bottom of the paper where it is then placed vertically in a solvent such as water where it soaks up the paper and carries the sample with it, it allows the mixtures to separate at different rates, so it just allows the “industry” to identify the different compounds in the mixture. Distillation- (simple) this is where a liquid is separated from a solution, commonly used to purify water to make it distilled where it is separated from the salty water, it is where the solution is heated up and the water evaporates from the solution, and goes in to a different container where it is firstly cooled and condensed, the salt from the solution cannot be carried so it is left behind, so to sum it up it is the process of “purifying” a substance by the process of heating and cooling. Precipitation- it is when a transition metal compound is mixed with a sodium hydroxide solution which leads to a displacement reaction, since sodium is more reactive then transitional metals so it takes over the transition metal place/position from the compound, the substance
Titration - Preparation,Neutralisation and Applications in Industry
Preparation of the Standard Sodium Hydroxide solution. P2. Aim: To make an accurate Sodium Hydroxide solution ready for titration. Apparatus: Sodium Hydroxide pellets, Pipette, Distilled water, Volumetric Flask, Spatula, Weighing scale, Goggles. NaOH: 23+16+1=40g. 40g NaOH in 1 litre (1000ml) 10g in 250ml 1g in 250ml 0.1 molar Method: Firstly we weighed out exactly 1 gram of the Sodium Hydroxide pellets ensuring accuracy to its highest to prevent any flaws in our results. We then carefully put the pellets into a volumetric flask. After that we poured approximately 100ml of distilled water into it and shook the solution for approximately a minute till the pellets were fully dissolved. Then we added approximately 150ml of water to make it 250ml we used the meniscus to maintain accuracy by
Column chromatography is a larger scale of thin layer chromatography.
Column chromatography is a larger scale of thin layer chromatography. In this case, the dye mixture- a two coloured compound- was added into the column. The separation of the two different colours began as a mobile phase- mixture of 50% ethanol and 50%water- was run through the stationary phase (alumina- Al2O3). The whole separation process depends on the polarity of the stationary phase, the mobile phase and the compounds composing the dye mixture. The compounds have their own equilibrium between being adsorbed onto the alumina and being soluble in the water-ethanol mixture; the most soluble or least adsorbed compounds travel fast down the column and hence could be separated from the other coloured compound. This could be explained through intermolecular forces; the alumina will form more hydrogen bonds compared to Van der Waals forces with the strongly polar compound. The hydrogen bonds form between the “highly electronegative oxygen atoms in Alumina” and the hydrogen atoms in the compounds. Whereas, the less polar compound will dissolve more in the water-ethanol mixture; and form less hydrogen bonds with the alumina compared to the number of Van der Waals forces that will also form. The compound which is adsorbed more will not travel as further as the compound with lower polarity. The compound with lower polarity will travel in the mobile phase, further down the
