This was so that the mussel samples would not go bad due to heat or harsh solvents. They were extracted with a mild solvent, and then concentrated by evaporation. The team found that the vapor was not toxic, but the residue after was. Other extractions were done to see how the residue separated when added with other mixtures of nonpolar solvents. In the toxic mussels, the visible light absorption spectrum revealed a pattern that was characteristic of phytoplankton pigments.
If there wasn’t enough solution to react with it then that would explain why we still had some left over that didn’t. For the zinc, the handbook says that it is insoluble in water but soluble in acid. Likewise we observed the same thing, the zinc did not dissolve at all in the water but became somewhat soluble in hydrochloric acid. The Zinc began to fizz but in the end not all of it was dissolved although there was significantly less than we started
Test Result Oxidase This laboratory test is based on detecting the production of the enzyme cytochrome oxidase by Gram-negative bacteria if no color change to purple or blue is evident at 30 seconds-1 minute then the result is positive. It is important that the test is read by one minute to ensure accurate results (avoid false negatives and false positives). Unknown 12 resulted in a negative test with no color change. These were similar results seen in Eschericia coli, Proteus vulgaris,
The average was 4.92 which is pretty close comparably to the standard. B. Why is it better to use white vinegar rather than dark vinegar for this titration? White vinegar is better to use due to the fact that it contains only acetic acid and water where other vinegars contain more chemicals. C. Write a balanced equation for the neutralization of acetic acid with NaOH.
This particular reaction is a strong acid and a strong base which means that when the reaction reaches the equivalence point, the moles of the acid and the base are equal and the solution is neutral so the pH should be around 7.0 depending on the final volume of each solution. To get this data, we will titrate an HCl solution with NaOH solution of which is a known concentration. We will record the initial and final reading of the NaOH while we record the pH of the titrated solution in the beaker. We will repeat this process with a solution of acetic acid which is a weak acid with NaOH and record the initial and final reading of NaOH and the pH of the solution in the beaker. Procedure Preview Calibrate the pH meter.
UNKNOWN ACID AND BASE TITRATION Introduction The purpose of this experiment was that we explored the use of titration by adding small quantities of base to an acid and recording the rise of the pH on a graph so we can see the equivalence point. In this lab we used a strong acid and a strong base to perform the acid base titration. Strong acids and bases are known to dissociate in water completely. Some of the major findings in this lab were that only a small amount of base can result in a large change in the pH. Procedure Step 1, Obtain acid, in a 100 ml Erlenmeyer flask add 35 ml of .2M HCl solution.
Even though the results under hexane and toluene are similar, the distances of original mixture, first and second fraction are different from hexane and toluene solvent because they have different polarity. As first fraction containing fluorene, which is much non-polar than fluoreone, fluorene in first fraction is much easier to carry by the moving non-polar solvent. Thurs, as the more non-polar the solvent is the longer distance that fluorene will move. Since hexane has larger non-polar carbon-hydrogen single bond groups than toluene, it is much non-polar than toluene. As the result of this, it can explain why the distance of fluorine in hexane is longer (1.3 cm) than the one in toluene (0.5 cm) and due to less non polar toluene has.
With the elemental reaction you get ZnI2 as your only product thus indicated that it is “pure” Zinc Iodide. In terms of ease, it would be easier to do the double replacement reaction simply for the fact that we wouldn’t have to swirl for at least 8 minutes to get ready to get results. With the double replacement reaction the swirling process becomes eliminated, and centrifuging takes less time. In terms of cost, it would be cheaper to do the elemental reaction if we’re thinking in terms of the 1:1 reaction. Theoretically speaking, if we use one granule of zinc and one granule of iodine opposed to one granule of Barium Iodide and one granule of Zinc Sulfate, the cost would be $.2123 in total for the elemental reaction and $.9265 for the double replacement reaction.
1A-Water/MSG: When shaken the water and MSG they mostly dissolve creating an orange gold color, the substance foams at the top from the vigorous shaking action yet still some MSG residue remains at the bottom of the test tube, it was unclear if the reason was because we did not mix it enough or rather we added too much MSG to the amount of water given. 1A-Alcahol/MSG: These two substances barely mix together leaving a transparent yellow tint to the alcohol as well as MSG that was unable to dissolve at the bottom of the test tube. We concluded that this residue was unable to be dissolved in this liquid because the amount of MSG remaining in the bottom of the test tube was around the same amount that was originally placed into the alcohol. 1B- Alcohol/Vegetable Oil: Created a foamy top layer, was semi unclear but as to the best of my observations the alcohol nearly completely dissolved the oil, leaving a foggy appearance to the once clear
The purpose of this lab was to find the molecular weight of two unknown substances by analyzing the freezing points in cyclohexane and to provide a visual representation of the freezing point depression effect. The theory of this lab is; by using measurements of mass of the unknown substances (solute) in correlation with the mass of the cyclohexane (solvent) and the freezing point constant of the solvent, you could determine the molecular weight of the solute by using the same math involved in deciding the freezing point of the solution/ The theory behind the visual of the FPD effect is that if one was to record the freezing point of a solution and two solutions of the same substances with more solute, one would see a visible drop in freezing point. The equations you needed for this lab were the freezing point formula for organic substances (ΔFp=(m)Kf) and the