Test for reducing sugars (Benedict's Test)
Additional reading materials for Chapter 5: Nutrition Carbohydrates: Mono-, Di- and Polysaccharides Below is the flowchart to show the relationship between monosaccharides (simple sugars), disaccharides (complex sugars) and polysaccharides (e.g. starch and glycogen). Important things to note: (a) Glycosidic bonds are chemical bonds that hold / join molecules of monosaccharides together. (b) Chemical formulae of monosaccharides, disaccharides and polysaccharides. (c) Polysaccharides are macromolecules, meaning they are very large molecules (made up of many many small monosaccharide molecules joined together in straight or branched chains). (d) Examples of monosaccharides, disaccharides and polysaccharides. Test for reducing sugars (Benedict's Test) Given an unknown solution, you are to find out if it contains reducing sugars ... so you have to carry out the reducing sugar test (Benedict's test). NOTE: What are reducing sugars?? A reducing sugar (all monosaccharides and some disaccharides) will produce a brick-red ppt when boiles with Benedict' s solution. Non-reducing sugar: Sucrose Procedures: . To 2 cm 3 of the unknown solution in a test-tube, add an EQUAL VOLUME (that is the same volume as the unknown solution used: 2 cm 3 ) of Benedict's solution (blue). 2. Shake the mixture and heat it by immersing the test tube into a boiling water bath (beaker
OBJECTIVE: To determine the content of iron in iron tablets by titration.
LAB: #3 DATE: 25th September, 2007 TITLE: Analyzing Iron Tablets OBJECTIVE: To determine the content of iron in iron tablets by titration. MATERIALS: . goggles and lab coat 2. 2 125cm3 conical flask 3. 1 250cm3 standard volumetric flask 4. 1 50cm3 burette 5. safety filler and pipette 6. 1 stand and clamp 7. filter funnel 8. Bunsen burner kit Chemicals . Iron tablets 2. 1.0moldm-3 sulphuric acid (200cm3) 3. 0.01moldm-3 Potassium Per Manganate 4. Distilled water/ wash bottles 5. soap solution PROCEDURES: Making a solution of the tablets . 5 iron tablets were weighed accurately, and then dissolved in about 100cm3 of 1.0 moldm-3 sulphuric acid in a conical flask. Some heating was required, but not more than the necessary needed to dissolve the tablets. 2. The mixture was filtered into a beaker, making sure that no solution was lost, then the conical flask was washed out with water and the washings were poured through the filter. 3. Finally, distilled water was poured over the residue and these washings we collected as well. The filtrate was then poured into a 250cm3 standard volumetric flask, washing out the beaker and adding washings to the standard flask. The mark was made up using distilled water. Titration
This assignment is primarily about lipids, triglyceride, unsaturated and saturated fats I will be stating the formation of lipids and what they are made of.
Joe Parr 12 hol Biology Assignment Lipids This assignment is primarily about lipids, triglyceride, unsaturated and saturated fats I will be stating the formation of lipids and what they are made of. Lipids are a group of substances which include fats and oils, steroids which include cholesterol and some of the sex hormones, and various other substances such as the waxes which cover insect bodies and plant leaves. Lipids are a mixed group of hydrophobic compounds composed of the elements carbon, hydrogen and oxygen. Triglycerides are commonly called fats or oils. They are made of glycerol and fatty acids. They are present in a wide range of living organisms and help to insulate and protect animals such as seal and marine birds. If there are no C=C double bonds in the hydrocarbon chain, then it is a saturated fatty acid (i.e. saturated with hydrogen). These fatty acids form straight chains, and have a high melting point. If there are C=C double bonds in the hydrocarbon chain, then it is an unsaturated fatty acid. These fatty acids form bent chains, and have a low melting point. Fatty acids with more than one double bond are called poly-unsaturated fatty acids. One molecule of glycerol joins together with three fatty acid molecules to form a triglyceride molecule, in another condensation polymerisation reaction. Phospholipids have a similar structure to triglycerides,
Acid-Base titration by double indicator method
Date: 01/12/2010 Objective To determine the proportions of sodium carbonate and sodium hydroxide in a mixture solution using double indicator method. Procedures . 25 cm3 of the mixture solution was pipetted into a conical flask. 2. Two drops of phenolphthalein indicator were added into the conical flask. 3. The mixture solution was titrated with the given standard hydrochloric acid(0.098M). 4. The mixture was titrated to the end-point. 5. At the end point, the pink colour of phenolphthalein indicator was just discharged. 6. The burette reading (x) was recorded. 7. Two drops of methyl orange and a further quantity of acid were added 8. The mixture was titrated to the end-point. 9. At the end point ,the yellow colour of the methyl orange changed to orange. 0. The reading of that further quantity of acid (y) was recorded. 1. The steps above were repeated 3 times. Results: Volume of piptte used: 25 cm3 The concentration of the hydrochloric acid used: 0.098M x Trial 2 3 Final burette reading / cm3 2.40 31.80 29.40 2.70 Initial burette reading / cm3 0.10 9.50 7.20 0.30 Volume of acid used(x) / cm3 2.30 2.30 2.20 2.40 Mean value of x= (12.30+12.20+12.40)/3 =12.30 cm3 y Trial 2 3 Final burette reading / cm3 9.50 38.80 36.60 9.80 Initial burette reading / cm3 2.40 31.80 29.40 2.70 Volume of acid used(x) / cm3 7.10 7.00
ACID RAIN The majority of people consider rain to be an undamaging weather occurrence. However the increase in acidity of rain is both unsafe and damaging. In order to fully understand the term acidity,
ACID RAIN The majority of people consider rain to be an undamaging weather occurrence. However the increase in acidity of rain is both unsafe and damaging. In order to fully understand the term acidity, it is essential to know something about the pH scale. This scale has a range of 0 to 14, with 7 being neutral. Anything below 7 (0-6) is known to be acidic and anything above 7 (8-14) is alkaline. A change in only one unit is equal to a tenfold increase in the strength of the acid or base. Therefore a unit change from pH 6 to pH4 is equal to a 10 x 10 increase in it acidity. Taking the above into consideration, it is easy to see how the normal phenomenon "rain" is becoming more and more acidic as its pH has dropped from around 6and 7 to about 4.3and 5.3.This occurrence is known as Acid Rain and was first noted in1852 by the English chemist called Robert Angus Smith. Acid rain in other words is the term used to describe rainfall that has a pH level below5.6. It is a form of air pollution that is currently a theme of huge debate due to its wide spread damages. It is responsible for the destruction of thousands of lakes and streams in the United States, Canada and parts of Europe. Acid Rain formation The two most important primary sources of acid rain are sulphur dioxide (SO2) and oxides of nitrogen (NOx). Sulphur is a colourless, pungent gas produce during the
An investigation of neutralization reactions
An investigation of neutralization reactions _________________________________________________________________ Aim Question : What is the effect of changing the concentration of an alkali, on the volume of acid needed to neutralise it, when acid is added to it? The plan is to use two acids (Hydrochloric & Sulphuric) and one alkali (Sodium Hydroxide). The reason I need to use two acids is; because the question applies to all acids and alkalis and to just use one of each would not enable me to come to a general conclusion. If there had been more time available, ideally I would have preferred to use two alkalis as well as two acids. Predictions First of all, here are the definitions for an acid and an alkali: An acid is a substance that forms hydrogen (H^+) ions when placed in water. It can also be described as a proton donor as it provides H^+ ions. An alkali is a soluble base and forms hydroxyl ions (OH^-) when placed in water. It can be called a proton acceptor because it will accept hydrogen (H^+) ions and form H[2]O. A Hydrochloric acid molecule (HCl) will release one H^+ ion and one Cl^- ion when placed in water. A Sodium Hydroxide molecule (NaOH) will release one Na^+ ion and one OH^- ion when placed in water. This means that one molecule of NaOH and one molecule of HCl will neutralise each other and produce H[2]O and a neutral salt called Sodium
To Estimate the Purity of Commercial Nitrite
Date: 9/9/10 Experiment No.: 1 Title: To Estimate the Purity of Commercial Nitrite Object: The purpose of this experiment is to check the purity of commercial nitrite by titration. Theory: Sodium nitrite (commercial nitrite) solution is oxidized by potassium permanganate to nitrate: 2MnO4- + 6H+ + 5NO2- --> 2Mn2+ 5NO3- +3H2O As potassium permanganate itself changes colour in this reaction, so no indicator is required. However, once sodium nitrite is acidified, nitrous acid will form and decompose (*). Thus, sodium nitrite is placed in burette and added to acidified potassium permanganate. *2NaNO2 + H2SO4 -->Na2SO4 + 2HNO2 3HNO2-->HNO3 + H2O + 2NO Experimental procedure: . Around ( (should be a little more for the impurity)) 0.90g sodium nitrite powder was transferred and weighed to the nearest 0.01g in a weighting bottle. 2. The sodium nitrite powder was dissolved in distilled water in volumetric flask of 250cm3 where the molarity was about 0.05M. 3. 25cm3 0.02M potassium permanganate solution was pipette into a conical flask, 15cm3 dilute sulphuric acid was added for acidification. 4. Sodium nitrite solution was transferred to burette for titration. 5. The initial burette reading was taken. 6. Sodium nitrite solution was slowly added to the acidified permanganate solution with continual swirling until the colour of the permanganate solution was just become
To find out how increasing the concentration of acid changes the speed of a reaction.
Investigating how changing an acid concentration Changes reaction rate Aim: To find out how increasing the concentration of acid changes the speed of a reaction. Reaction Used: Magnesium + Hydrochloric acid - Hydrogen + magnesium chloride. Mg + 2HCL - NgCL2 + H2 Prediction: As the acid gets stronger, the reaction will go faster. This is because in a stronger acid, there are more particles of acid which collide into the magnesium ribbon. In a weaker acid, you wont get as many acid particles per litre, so there will be less collisions with the magnesium ribbon. Equipment and Reagents: 4 concentrations of Hydrochloric acid - 0.5 m 1.0 m 1.5 m 2.0 m Strips of 3cm magnesium ribbon Ruler Scissors Beaker Goggles Pippet Funnel Fair testing: There are two different factors to the fair testing of this experiment, they are what we Will Control and what Will Vary. Will Control: We will control the following things - Size of the magnesium strip - The temperature of the acid - The movement - The pressure - How to put the magnesium into the acid Will Vary: The things what will vary are - The concentration of the HCL Method: The method will follow in the bullet points below; * Collect equipment * Measure and cut the magnesium ribbon into equal strips to make this experiment a fair test. * Measure the weakest acid to 10cm3 using a measuring cylinder and
Nuclear Fusion as energy provider
For ?-decay, unstable atom emits an ?-particle, this can also apply to ?-decay. To distinguish ?-decay and ?-decay, here is a number of characteristic of each of the decay: relative charge, relative mass, nature, range, material to stop, deflection in electric field and magnetic field. ?-emission ?-emission Relative charge +2 -1 Relative mass 4 0.00055 Nature 2 protons + 2 neutrons (Helium nucleus) Electron Range 5cm 6m Material to stop Paper Aluminium(5mm thick)[] Deflection in electric field [2] Slightly towards negative terminal Greatly towards positive terminal Deflection in magnetic field[2] Slightly upwards Greatly downwards As an example, Bismuth can decay into Thallium and Polonium by emitting ?- and ?-particle respectively. For ?-decay of Bismuth: For ?-decay of Bismuth: The example above can show ?-particle is Helium particle while ?-particle is electron. Radioactive decay is different from fission reaction. Radioactive decay Fission . unstable . absorb 1 neutron 2. emit ?/?/?- particle 2. oscillate 3. become other elements 3. unstable 4.Fission (split) 5. give out 3 neutrons Fission reactions differ from radioactive decay both in the way that the reaction must be started and in the type of products that are formed [1]. Radioactive decay is a passive action, while fission is active. For radioactive decay, the atom is unstable;
Describe the construction, operation and application of distillation equipment used in industry
Faculty: Technology Assign/Activity Code: 306/02 Course Title: C&G 0603 - Process Technology Instructions for the use of this cover sheet (1) A cover sheet is required for every activity including presentations (2) Please complete all sections below (3) Staple the cover sheet to your activity Student name: Billy Whelton Unit(s): LEVEL 3 Unit 306: Distillation in the Process Industry Assignment/ Activity title: 02 - Distillation equipment & Their Safe Use Hand out date: 0-12-2007 Hand in date: 01-04-2008 Graded (Y/N) N Resubmission date for referred work: 08-04-2008 Student's comment on activity (if applicable): Student's Signature: ................................................ Date: ................. Assessment Grading Decision (by Assessor). Assessment decision following Verification. Activity designed by Assessed & graded by Key Skills Assessed by Name: Geoff Martin Name: Date: 28-06-05 Date: Internally Moderated by Internally Verified by Name: Name: Date: Date: You must store all marked activities in a portfolio (folder) for External Verification during the academic year. Grading descriptors PASS You have successfully completed all tasks and submitted all evidence as stated. Task Comments Pass Criteria Met Yes/No Grading Comments Overall Grade P/R Hand in date for referred work .................. Outcome 2:
