Research Question 1: What is the effect of varying concentrations of luminol (1%, 2%, 3%, 4% and 5% w/v) on the oxidation of luminol when reacted with sodium hypochlorite (3%) as measured through change in light intensity (lx)? Research Question 2: What is the effect of varying temperatures (0, 20, 40, 60 and 80) in kelvin on the oxidation reaction between luminol and sodium hypochlorite measured through the change in light intensity (in lx) in order to determine activation energy of the reaction? Hypothesis: As concentration of luminol increases, the amount of light intensity produced will also increase. At 5% luminol, brightest light intensity will be recorded as a result of most frequent collisions. An increase in temperature will increase …show more content…
In such cases, oxidation refers to the loss of electrons and reduction refers to the gain of electrons by molecules, atoms and ions. Redox reactions, always involve the simultaneous oxidation of one reactant with the reduction of another as electrons are transferred between them3. The reactant that accepts the electrons is called the oxidizing agent. In the process of bringing about oxidation, it becomes reduced3. The other reactant that supplies the electrons is known as the reducing agent. In the process of bringing out reduction, it becomes oxidised3. Luminol (5- Amino-2,3-dihydro-1,4-phthalazinedione)4 is a chemical compound that contains amine groups, two carbonyl group and multiple double bonds (C8H7N3O3). It has a yellow crystalline structure and it is soluble in suitable solvents but it is insoluble in water4. When luminol is reacted with an appropriate oxidizing agent, it is reduced and in the process it produces a blue …show more content…
At this point, the compounds are at an electronically stable position at equilibrium. When solutions containing ClO- ions such as sodium hypochlorite are added, there occurs a collision between these ions and the dianion of luminol and hence a transition state is reached5. At the transition state, the intermediate has high energy and electrons are seen to be in an excited electronic state5. Henceforth, the electrons move to a higher energy level which makes them unstable and the electrons of the high-energy intermediate are seen to fall back to ground energy. In the process, photons of light are emitted5. In this case, the unit of illuminance is represented in lux, which measures as luminous flux per unit
Absorbance was defined as: log I_o/I where I_o is incident light and I is the transmitted light. Fluorescence emission spectrum is different from fluorescence excitation spectrum because it records different wavelengths of chemical s...
... samples before the incubation of 108 seconds. Then the 100 µL of colour reagent was put to the sample, merged and incubated for further 10 minutes. The absorbance at 615nm and 700nm wavelengths was calculated on the samples in the Cobas analyser and the sample concentration was measure according to :
As the light is increased so would the rate of photosynthesis. Apparatus: boiling tube, 250ml beaker, bench lamp, ruler, sodium
Experiment #3: The purpose of this experiment to test the chromatography of plant pigments the alcohol test strip test will be used.
Light sticks work in a similar way. When you “snap” a light stick, the chemical in the glass capsule mixes with a chemical in the plastic tube and creates light energy. Instead of the chemicals used by a firefly, other chemicals are used to create a glow. The light stick that you can buy at a store usually contains hydrogen peroxide, phenyl oxalate ester, and fluorescent dye (New York Times Company, 1 of 3). The light stick will glow the same color as the fluorescent dye placed in it. In luminescence, the chemical reaction “kicks an electron of an atom out of its ‘ground’ (lowest-energy) state into an ‘excited’ (higher-energy) state, then the electron give back the energy in the form of light so it can fall back to it’s ‘ground’ state (Fluorescent Mineral Society, 1 of 2).
After five the test tube was removed and cooled to room temperature. Three more test tubes were obtained and labeled 1, 2, and 3. The correct reagent was added to each test tube as seen. The spectrophotometer was adjusted
Experiment is to investigate the rate of reaction between hydrochloric acid and calcium carbonate Hydrochloric acid + Calcium Carbonate Þ Calcium Chloride + Water + Carbon Dioxide 2HCl (aq) CaCo3 (s) CaCl2(s) H2O (aq) CO2 (g) There are a number of variables in this experiment and these are listed below as input variables and outcome variables.
In the late 1800’s it was discovered that papa-amino-phenol, could reduce fever, but the drug was too toxic to use. A less toxic extract called phenacetin was later found to be just as effective but also had pain-relieving properties. In 1949, it was learned that phenacetin was metabolized into an active but also less toxic drug, acetaminophen. Since then, acetaminophen has been sold under many over the counter brand names, most popular being Tylenol.
However, there is no color change at end point of these reactions, so an indicator had to be added into the solutions to indicate the end point. An indicator is a chemical which is used to indicate the presence of the another substance in the solution; it changes colors when the ions H+ are added or removed by dissociation reaction. In this experiment, phenolphthalein was used as an indicator to indicate the presence of base in a solution by changing the color of the solution from colorless into pink. When the concentration of H+ is low, the solution becomes pink, and when the concentration of ions H+ is high, it becomes clear. The equivalent point is determined when there is a color change from colorless into light pink, and it is also an approximation of the end point. The concentrations were calculated by the equation M1V1 = M2V2, which means that the moles number of the base must equal to the moles number of an acid. The mole ratio in these reactions are 1:1 that means the moles’ number of the first reactant is equal to the moles’ number of the second one at the end
Input variables In this experiment there are two main factors that can affect the rate of the reaction. These key factors can change the rate of the reaction by either increasing it or decreasing it. These were considered and controlled so that they did not disrupt the success of the experiment. Temperature-
What is the difference between Temperature 2. What is the difference between a'smart' Concentration (Pressure for gases). 3. What is the difference between a's Catalyst 4. What is the difference between Surface area In my investigation I will be testing how changing the concentration of the hydrochloric acid,.
The aim of my investigation is to find out whether the increase of temperature increases the rate of reaction between the two reactants of Sodium Thiosulphate and Hydrochloric acid. I will then find out and evaluate on how temperature affects this particular reaction. Factors There are four main factors, which affect the rate of reaction that are considered as variables for the experiment I will be doing, they are the following: Molecules can only collide when two of them meet together.
The aim of this investigation is to: 1) find the rate equation for the reaction between hydrogen peroxide, potassium iodide and sulphuric acid by using the iodine stop clock method and plotting graphs of 1/time against concentration for each variable. Then to find the activation energy by carrying out the experiment at different temperatures using constant amounts of each reactant and then by plotting a graph of in 1/t against I/T, 3) to deduce as much information about the mechanism as possible from the rate equation.
of a gas, liquid, or other substance-are excited so that more of them are at
My aim in this piece of work is to see the effect of temperature on the rate of a reaction in a solution of hydrochloric acid containing sodium thiosulphate.