BISC110/S13: Series 3 Lab 9 Hill Reaction - OpenWetWare
BISC110/S13: Series 3 Lab 9 Hill Reaction
BISC110: Series 3 Experiment 9 Hill Reaction - …
High school experiments on heats of combustion usually involve burning a candle or alcohol and trapping the heat in a beaker of water. The errors are usually massive and chimneys etc are used to try to trap the heat - with little success. How could the accuracy be improved? You could explore ways and provide a theoretical reason for your trials. Alternatively, you could compare the accuracy of ΔHC values of methanol, ethanol, propanol; or even of the three C4H9OH isomers. Why might the accuracy be different? What does this tell you about intramolecular bonding? Are there any correlations with BPt?
Here's a comment off a health food blog from a guy called Vincent: "I was too lazy to wash out a 2 L carton of orange juice after dinner last night. I go to wash it out today and the carton was bulging quite noticeably. Those crazy orange juice fermenting bacteria work fast! The carton let out a nice puff of air when I opened it up and it tastes so sour." What has happened here? Orange juice has a lot of natural sugars in it. Bacteria love it if you let them get in. The refrigerator only slows growth of bacteria, it doesn't kill them.
Nutrition, digestion and excretion
But how to get samples of these gases? You may have cylinders but you could produce H2 and CO2 by reaction (or let some dry ice sublimate); let some liquid nitrogen evaporate (or remove oxygen from air). And why not propane (BBQ gas) or butane (cigarette lighter fluid)? Remember that balloon gas is not just helium - it has 3% air mixed in with it. The main point is that the law holds for ideal gases but at atmospheric pressure and room temperature they won't be that ideal. And is the deviation from ideality dependent on the molar mass of the gas, or whether it is polar or non-polar, and where on earth do you get a polar gas from (HCl is too dangerous)? What range of temperatures will you use (consider liquid nitrogen, dry ice). What value will they give you for absolute zero when the V/T graph is extrapolated? How do you draw the line of best fit (is least-squares the best, does it give you the most accurate value for absolute zero?). And what is the volume of the gas in the apparatus? And what is the best way to measure temperature (of the gas as in the diagram, or of the water surrounding it)?
A good EEI would be to take some calcite to represent the calcareous organisms. Calcite is the most common form of the mineral whereas marble is the metamorphic form. Really, I guess you could use either. To a weighed sample you could add some acidic buffer solution of various pHs and let it react for a set time (maybe 30 minutes). Dry and reweigh. If the pH drops during the reaction add more buffer. What does the graph look like? Is pH that critical? Perhaps you should do triplicates. What about temperature (ocean warming): you could try a change in temperature as a separate variable. I think you may be shocked. There is an interesting article titled "Laboratory Experiment Investigating the Impact of Ocean Acidification on Calcareous Organisms" by Alokya P. Perera and A. Bopegedera in the J. Chem. Educ. 2014, 91, 1951−1953.
Practical Biology | Nuffield Foundation
You would then plot acidity on the y-axis and time elapsed on the x-axis. The rate of reaction would be the slope of the line at a particular time. Does the rate vary over the whole time period? Does the rate vary as the acidity increases (is there a relationship)? Perhaps you could compare red and white wine. Does the red anthocyanin in the red wine act as an antioxidant as some people believe? What a fabulous EEI, and you'd even have some wine vinegar for your fish and chips afterwards.
It would be interesting to see how fast this happens. If you leave it out for 24 hours will it be completely flat? And what does 'flat' mean anyway (there will always be some gas dissolved in the liquid). This would be a great EEI. You can flatten some soft drink to use as a control. Heating is the simplest way to decarbonate it.
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Lab 4 Photosynthesis - SlideShare
DCPIP is a dark blue solution that becomes lighter as it is reduced.
Vitamin C - Wikipedia
Spinach Photosynthesis Experiment by emily elder on …
Vitamin C, also known as ascorbic acid and L-ascorbic acid, is a vitamin found in food and used as a dietary supplement
15/10/2015 · DCPIP Test Investigation ..
As a trial, I took a 1 cm3 cube of marble and placed it in 200 mL of 7.5%w/v citric acid solution (pH 1.8) at 50°C (with stirring) and after 60 minutes it had lost 0.30 g. Why not make up a synthetic soft drink from phosphoric or citric acid. What concentration will you choose? How does the reaction rate or the extent of the reaction vary with concentration? Does temperature have much effect on the rate? Does the product - calcium citrate or calcium phosphate - impede the progress of the reaction; that is, how soluble are the products (one is 4 times as soluble as the other). How do you measure the progress of the reaction (amount of carbonate consumed or change in titratable acidity of the solution)? Oh, the possibilities are endless. And you can drink the left-over Coke and rot your teeth a bit more at the same time. A perfect EEI.
(the light dependent reaction of photosynthesis) - Duration: ..
Applying ultra-violet visible spectrophotometry and various types of chromatography to compare the amounts of certain photosynthetic pigments in fresh, frozen, and canned phaseolus vulgaris and spinacia olercea.
Lab: Exploring the Rate of Photosynthesis - The Biology …
An interesting EEI would be to measure the water absorption properties of the acrylate polymer using 'fake' urine (water, sodium chloride, urea, hydrochloric acid perhaps) in water in appropriate amounts. Does the nappy work equally well on individual solutions of the urine components (or are polar compounds different to non-polar ones)? How does temperature affect its properties? Where to get the polyacrylamide. You could rip open a nappy but a more controlled way would be to buy "water storage crystals" from the hardware shop. Get a Materials Safety Data Sheet (MSDS) for the one you buy to see what percentage of the crystals are polyacrylamide (should be over 90%).
Measuring the rate of photosynthesis - Science and …
It is known that for water to be electrolysed, it has to have an ionic substance added such as sodium chloride. You could see how the efficiency of the electrolysis is affected by the voltage across the electrodes, and by the concentration of salt present. You'd need to relate your results to the E° value for the non-spontaneous reaction and what happens at voltages lower than that. You may look at the changing rate of generation of the gases as time passes or at the volume after a set time. It's up to you. Does the car ad below make sense? Is it chemically feasible?
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