Chem Pre-Lab Essay

All standardizations are performed in triplicate. Weigh out .1000-.1200 gram KIO3. Add 70-80 mL of deionized water. Swirl and dissolve. Add 3 mL of 6M HCl. Swirl and mix. Quickly titrated the brow-red solution with 0.1M Na2S2O3 until it is light yellow. Then add 3.5 mL of starch indicator. Titrate again until the dark color first disappears.

4. It would be difficult to measure the concentration of acid in red wine or coca-cola because the colour of the drink is too dark for us to see when the phenolphthalein indicator changes colour. You could overcome this difficulty by using a pH meter.

10 microliters of the sample is then added and the assay absorption is measured at 340nm. If absorbance was above 1.5, samples were diluted.

11) Dry out the methylene chloride solution that contain the benzoin and the dibromobenzene by the use of anhydrous sodium sulfate.

The purpose of this semester long experiment was to determine an unknown organic acid. An organic acid is an organic compound with acidic properties. A base reacts with acids to form salts. Titrations are used to determine the concentration of unknown substances. The purpose of the KHP experiment was to determine the molarity of NaOH. HCl titrations are mainly to check technique and used to verify the molarity of NaOH solution. The hypothesis is that this acid is C4H3OCOOH.

Enter the precise mass in GRAMS of the potassium iodate used to prepare your primary standard solution.

The proof (twice the % alcohol) starts at its maximum and goes down (as the alcohol evaporates). If we start with a high concentration of alcohol, we will get the azeotrope (95% alcohol, 5% water) for a while, then the concentration will decrease.

The purpose of this experiment was to determine the pKa, Ka, and molar mass of an unknown acid (#14). The pKa was found to be 3.88, the Ka was found to be 1.318 x 10 -4, and the molar mass was found to be 171.9 g/mol.

After the twenty minutes elapsed, the flask was cooled to room temperature and then titrated with the remaining NaOH until the colorless solution remained pink. The final volume was then recorded. While solution #1 was heating the same process was repeated with solution#2 and the second burette

Purpose: The purpose of this experiment is to observe a variety of chemical reactions and to identify patterns in the conversion of reactants into products.

The luminous yellow flame is smoky because no air is entering the burner and hydrocarbon is converted into carbon dioxide

Observe and measure a weak acid neutralization and determine the unknown identity of an unknown acid by titration.

The purpose of this lab was to become familiar with the three different balances and two different methods used to find the weight and mass of chemicals and compounds in the ChemLab program. The lab was performed by using three different types of balances, and the direct weighing and weighing by difference methods.

To determine the vitamin C content in commercial vitamin C tablets by titration between vitamin C (ascorbic acid) & iodine solution. Hence, compare this data with the manufacturer 's specification.

Mass of 3.3 x 10-8 moles of ascorbic acid = 3.3 x 10-8 x 176g = 5.808 x 10-6g = 5.808 x 10-3 mg/mL