In this experiment the purpose was to synthesize a synthetic dye, methyl orange, and test its effectiveness by performing a dye test with fabric. Methyl orange is an azo dye made from a synthesis reaction between sulfanilic acid and N,N-dimethylaniline. The preparation for this synthesis involves two steps: diazotization and coupling reaction. The diazotization step is the first step where the sulfanilic acid sodium salt reacts with the sodium nitrite in HCl to form an unstable diazonium salt. The coupling reaction is the second step where the diazonium ion is used in the reaction mixture and reacts with N,N-dimethylaniline to form an acidic azo dye.
Procedure:
Pretreatment Before Diazotization Reaction A mixture of 0.55 g of Na 2CO3 and
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This solution was poured into the diazonium salt ice water mixture. When it was added, it turned the solution red. This solution was stirred for about 15- 20 minutes to insure the reaction was completed. Then 15 ml of NaOH was slowly added to the cooled and stirred crude reaction mixture until the pH was basic.
Isolation of the Crude Dye The stirred crude basic reaction mixture was carefully boiled with a hot plate for about 10 minutes. When most of the dye was dissolved, 5 g of NaCl was added. The crude reaction mixture was then cooled in an ice bath. Then a vacuum filter was set up and two washes were performed with 10 ml of cold NaCl solution. The precipitate was kept after. The crude solid dye weigh 0.37 g.
Methyl Orange Dye Bath A mixture of 0.25 g crude dye, 5.0 ml of 15% Na2SO4 and 5 drops of concentrated H2SO4 was added into a beaker containing 150 ml of water and a magnetic stir bar. The solution was then boiled using a hot plate and the fabric was added to the dye bath. The fabric was allowed to stir for 5 minutes. Then it was removed and rinsed with water.
Results:
Percent yield calculation of crude methyl orange dye product:
0.37g/( 2.0 g) x 100= 18.5% percent
Living organisms undergo chemical reactions with the help of unique proteins known as enzymes. Enzymes significantly assist in these processes by accelerating the rate of reaction in order to maintain life in the organism. Without enzymes, an organism would not be able to survive as long, because its chemical reactions would be too slow to prolong life. The properties and functions of enzymes during chemical reactions can help analyze the activity of the specific enzyme catalase, which can be found in bovine liver and yeast. Our hypothesis regarding enzyme activity is that the aspects of biology and environmental factors contribute to the different enzyme activities between bovine liver and yeast.
Lab 4: Energy Conservation: Hot Stuff!! The purpose of this experiment is to try to find the original temperature of the hot water in the heater using the 60 degrees C thermometer. Use your 60°C thermometer, and any materials available in your laboratory, to determine the temperature of the water in the coffee pot. During this experiment we calculated the original temperature of a heater after it had been cooled down, and we did this by measuring hot, cold, and warm water, with a thermometer that had tape covering 60 degrees and up.
Experiment: First prepared a well plate with the appropriate amounts of distilled water, HCl, and Na2S2O3 in each well according to the lab manual. The well where the reaction
The purpose of this experiment was to prepare two solutions and use them to perform a precipitate reaction. Then using the results and mass gathered from the experiment, to determine the limiting reagents and to calculate percent yield.
This experiment demonstrated the ability of agarose gel electrophoresis to separate the mixture of dyes into their individual components by the application of a combination of dyes to the same sample well. The experiment effectively demonstrated that the dyes where different in structure, energy, and composition. Most of the dyes where negatively charged at neutral pHs and only one with positive charge. The positive charge one moved an opposite direction compared to the other dyes.
Early dyes were made using natural resources, like plants, berries, minerals, and seeds. Some of the earliest examples of cloth dyed with these natural substances come from ancient Egypt. During ancient times, the cloths, just like the dyes, were made from natural fibers, like cotton, linen, and wool. Later, as advancements were made in chemistry and manufacturing, humans learned to make synthetic fibers. By understanding how the molecules of dye react with the fibers, chemists can design many vibrant dyes that do not fade or run off when washed. In addition to what type of material they are made from, another way to categorize fibers is by their chemistry. Cotton and linen fibers are cellulose-based. Cellulose is the main component of plant
Chemistry is also beneficial in studying the chemical construction of hair dye and therefore learning how and why it works. The first safe commercial hair color was created in 1909 by French chemist Eugene Schuller, using the chemical paraphenylenediamine.
Usually, people do not give much thought to the fact that much of what they consume is artificially coloured. People associate certain colours with certain flavours; the colour of food has a great effect on the perceived flavour in anything, in some situations even the colour of the container can make a difference in consumer purchases. For this reason, food manufacturers add dyes to their products, sometimes the aim is to simulate a colour that is perceived by the consumer as natural because consumer acceptance is really important. Colour has a really vital role when purchasing food and adds to our enjoyment of eating.
20cm3 of distilled water was put into a beaker which was placed on a hot plate. 9.02g of oxalic acid was added in the beaker and stirred. The temperature was monitored with a thermometer till it reached about 50°C and all the solid was dissolved. Small aliquots of 3g potassium dichromate were then added. Heating was resumed and when there was no more visible reaction, 3.5g of potassium oxalate was added.
For this experiment we used titration to standardize the exact concentration of NaOH. Titration is the process of carefully adding one solution from a buret to another substance in a flask until all of the substance in the flask has reacted. Standardizing is the process of determining a solutions concentration. When a solution has been standardized it is referred to as a standard solution. To know when a solution is at its end point an indicator is added to acidic solution. An indicator is an organic dye that is added to an acidic solution. The indicator is one color is in the acidic solution and another color in the basic solutions. An end point occurs when the organic dye changes colors to indicate that the reaction is over (Lab Guide pg. 141).
It can be dyed withacidic or active dyestuffs. Particularly when dyed with active dyestuff, the colour of product will be fresh and lustrous. With good fastness to light and perspiration, it also has good dyeing brilliance and dyeing fastness in comparison with real silk products.
Nature has gifted us with more than 500 dye-yielding plants [30]. One such dye –yielding plant species is Tagetes erecta Linn. , commonly known as Mexican Marigold because of its origin. This research was performed with the explicit objective of extracting natural dye from the petals of Mexican marigold flower using different solvents such as Methanol, Ethanol and Water, and to investigate its dyeing effects on different fabrics and yarn samples. The effects of various mordants on the stability of the dye as well as on the dye color were also analyzed. The color shade differences, L*a*b* values and color strength (K/S values) were estimated using CCM software analysis via Gretag Macbath 7000 A º spectrophotometer. Light fastness, Wash fastness, and Rubbing fastness were also evaluated for fabrics and yarns.
1.Describe three different techniques which can be used to separate two component mixtures e.g. of water soluble dyes, an insoluble solid from a liquid and a mixture of two different amino acids.
Now add the cold NaOH solution prepared above to the cold (not over +5°C) Alclorite solution. Allow to stand at room temperature until temperature reaches 20°C. Now heat to 80-85°C over 10 minutes and hold there for at least two minutes but not more than five. Cool in water to room temperature.
The dyes & dye intermediate industry consumes large quantity of water & produce large volume of wastewater from different generated steps in dyeing process. The effluents generated are heavily coloured & contain high COD/BOD value. The effluent causes depletion of dissolved oxygen which has an adverse effect on the aquatic ecological system. There are certain physio-chemical, biological & advanced wastewater treatment technologies which are helpful in wastewater treatment of dye industry such as ion-exchange, adsorption, coagulation, R.O, chemical precipitation & electrocoagulation. Since electrocoagulation is very effective in removing dyes from large volumes of effluents & low in cost so it is mostly used. The main advantage of