Determining the Effect of Different Sugar Concentrations on Benedict's Solution
PLANNING:
Hypothesis and prediction:
My hypothesis is that the sugar solution with the highest
concentration will turn the precipitate the darkest colour. This will
be the 10% sugar solution. This is because the more amount of sugar it
contains the more it will reduce the Copper. It will be a much darker
precipitate compared to the other two.
Background theory:
Benedict's solution is an aqueous solution of Copper (II) Sulphate,
Sodium carbonate and Sodium citrate. It is an alkaline solution used
to test for the presence of aldehyde groups (RCHO). The reducing sugar
(Glucose) reduces the copper (II) Sulphate to Copper (I) oxide. The
colour of the precipitate varies dependent on the strength of the
reducing sugar present. The colour can vary from blue to red-brick:
indicating a high concentration of sugar. Glucose contains an aldehyde
group, so it is able to reduce the Benedict's solution and form a
precipitate. An aldehyde contains the general formula; RCHO, where the
R represents Hydrogen. They are formed from partial oxidation of
primary alcohols. An aldeyde is formed due to cabonyl groups; these
contain an Oxygen atom joined by a double bond to carbon. If the
carbonyl is joined to a hydrogen atom, then the compound is an
aldehyde. Glucose is a monosaccharide. Monosaccharides can take the
form of linear or ring structures. The carbonyl on the carbon 1
supplies the electron which joins the carbon 1 to carbon 5. When this
bond breaks, there are extra electrons which are then used to reduce
other molecules. The heating thus breaks these bonds, so then the free
electrons reduce the Copper (II) Sulphate to Copper (I) oxide in the
Benedict's solution. The reason why the Benedict's solution is readily
reduced is because it has a high PH, hence alkaline, whereas the
Carboxyl group in the Glucose gives it acidic properties. It splits
open the ring structure, consequently releasing the electrons which
are accepted by the Copper. The Copper (II) ions act as a mild
If this experiment were designed to determine the amount of Fructose in a solution, describe what, if anything, would need to change in the reaction? Explain why there would or would not need to be changes. (5
CL-, as the ions of H+ and OH- react to form H2O. These spectator ions
Carbohydrates are biomolecules that consist of a chain or ring of carbon atoms attached to hydrogen and oxygen atoms. The simplest formula for carbohydrates is (CH2O)n. Carbohydrates are important to organisms for a variety of reasons. They are used to form the structural components of the cell, aid in energy storage, and serve as intermediary compounds for more complex molecules. Carbohydrates are classified as either monosaccharides, disaccharides, or polysaccharides. Both monosaccharides and disaccharides dissolve easily in water. Carbohydrates are produced in plants through the process of photosynthesis and animals obtain these carbohydrates by eating the plants. ("BIO 1510 Laboratory Manual," 2016)
· Add 2g of yeast to the water and add sugar (1g, 2g, …up to 5g).
The Sugar Busters diet claims that sugars, such as refined sugar and sugar processed by the body-starches and complex carbohydrates, are toxic to the body. The Sugar Busters diet operates under the belief that only a certain amount of insulin is necessary for survival, and too much will have a negative impact on the body. The intent of the Sugar Busters diet is to lower cholesterol level, obtain weight loss, increase energy, and improve the body’s health; the diet achieves this by eliminating food high in sugar from the diet. Sugar is eliminated from the diet because it stimulates excess insulin to be produced by the body, which increases cholesterol level and allows the body to store fat. By controlling the insulin, the body can use stored
I used Cheerios, distilled water, and a pestle and mortar. I ground the Cheerios until they had a fine, sand-like texture and consistency. I then added distilled water and mixed until I was left with a thin, runny solution, that was beige in color. Once I had the stock solution made, I was able to perform my first experiment, beginning with Benedict’s reagent. For this experiment I used a hot plate, beaker, and three test tubes, one labeled + (positive control), - (negative control), and Cheerios. Two milliliters of each solution was then added to the tubes they were labeled to go into. In this experiment, the positive control was a glucose solution. I then added two milliliters of Benedict’s reagent to each tube. Once a boiling bath had been made using water, the beaker, and the hot plate, each of the three test tubes were places, sitting upwards, into the boiling bath. A timer was set for three minutes, and I recorded the color
Record any observations made. (A clear positive reaction for the 2% glucose control and a clear negative reaction for the water control should be seen).
== § Test tubes X 11 § 0.10 molar dm -3 Copper (II) Sulphate solution § distilled water § egg albumen from 3 eggs. § Syringe X 12 § colorimeter § tripod § 100ml beaker § Bunsen burner § test tube holder § safety glasses § gloves § test tube pen § test tube method = == = =
For my preliminary work, I used a 50 mm piece of potato. It was easy
I blended on high to make the potatoes more liquid-like. I grabbed the cheesecloth and placed on the top of the blender. I poured the potato extract on the container and labeled it. I found out that I have to make 1% sugar solution so I grabbed the sugar and measured into 5 grams on the scale. I added 5 grams of sugar on 250 ml graduated cylinder and poured the water into the cylinder. I mixed the sugar with water and poured it into the saucepan. I refilled the water into the graduated cylinder and poured into the saucepan. I turned on the heat of the stove and saw the sugar dissolved. I poured into a container and labeled 1% sugar solution. I repeated the same thing with 1% salt solution by using 1 gram of salt and filled the water into graduated cylinder by 100 ml. I answered question three. In the first experiment, I grabbed four transfer pipets and used it to put solutions into the test tubes by 3ml. I labeled it and placed into the plastic cups so it can stand upright. I grabbed each test tube and poured 2 ml of catalase solution into it. I also tapped and swirled to measure the bubbles by using the ruler. I wrote the numbers into the lab report. In the second experiment, I labeled the room
Tollens' reagent is an alkaline solution of ammoniacal silver nitrate. There is brown precipitate which is the silver hydroxide present and it will dissolves in aqueous ammonia, forming the diamminesilver(I) ion, [Ag(NH3)2]+. Aldehydes is then reduce the diamminesilver(I) ion to metallic silver and is oxidised to a salt of the corresponding carboxylic acid. Similar to Fehling’s test and Benedict’s test, Tollen’s reagent test will not react with ketones (Baker, 2007). The wall of glucose and fructose solution are deposited by layer of silver mirror while maltose solution has grey precipitate of silver within the solution. Even grey precipitate is shown in maltose solution instead of silver mirror layer, the result is still positive. This is because glucose, fructose and maltose are reducing sugar that contain of free aldehyde sugar which can reduce the diamminesilver(I) ion to metallic silver(Clark, 2004). The electron-half-equation for the reduction of of the diamminesilver(I) ions to silver
One major change I would make into the procedure is the to make a more efficient way to extract the sugar. To make it more efficient fi...
...r 15minutes. I would keep the method the same as I did doing this investigation but try a salt solution instead of sucrose as it would be easier to make different concentrations by having a certain amount of salt per 100cm³ of distilled water.
Experimental Strategy: In this experiment, the yeast being used is called Saccharomyces cerevisiae. This type of yeast follows fermentation which is very unique and can tell how much carbon dioxide is produced by fermentation more accurately compared to cellular respiration. Three test tubes will be filled with a specific volume and concentration of sugar with a certain amount of yeast in each test tube. Two of the three test tubes will have similar concentrations of sugar with different amounts of yeast...
The experiment was only an indication of what length of potato chip `I should use. I decided to use the three cm lengths of potato chip because it gave a bigger percentage change therefore I would be able to acquire clearer results. The results are shown below. Length of Potato Chip Before Length of Potato Chip After Percentage Change Distilled Water 2 cm's long 3cm's long 2.03cm's long 3.1cm's long 1.5% increase 3% increase Diluted Sugar Solution. 0.2mole dm -3 2cm's long 3cm's long 1.68cm's long 2.52cm's long 16% decrease 42% decrease Concentrated Sugar Solution.