Date 5/8/2013 Introduction to Organic and Biochemistry CHM 132 Unit 15 Lab (Body Fluids) Buffers Report Sheet Record the properties of each of the flasks on the table below: |Property |Flask 1 |Flask 2 |Flask 3 |Flask 4 | |Contents | | | | | |Initial pH |7.0 |7.0 |7.88 |7.88 | |pH after adding strong acid |2.32 | |6.16 | | |pH after adding strong base | |11.68 | |11.79 | 1. Compare what happen to the pH of flask 1 to what happened to the pH of flask 3 when HCl was added. The pH of flask 1 dropped much more than that of Flask 3. 2. Which substance, water or the buffer does a better job of maintaining pH when small amounts of strong acid are added?
Through these calculations, the concentration of hydrochloric acid was found to be 8.3 mol•L-1. Purpose Refer to handout “Standardize an Approximately 1 mol•L-1 Hydrochloric Acid” Material and Method Refer to handout “Standardize an Approximately 1 mol•L-1 Hydrochloric Acid” Results Quantitative Results Trial Initial Final Reading (in mL) Volume HCl Used (in mL) 1 0.2 12.4 12.2 2 12.4 23.9 11.5 3 23.9 36.3 12.4 Calculations Average volume of HCl
Repeat the titration until there are two titres within 0.1cm3 of each other. Record results in a suitable table. Results: Rough Titre: 7.653 First Run: 6.553 Second Run: 6.453 Third Run: 6.553 Calculations: During the titration, iron(II) ions are oxidised to iron(III) ions and manganate(VII) ions are reduced to manganese(II) ions. The equation is as follows: 5Fe2+(aq) + MnO4-(aq) + 8H+(aq) ? 5Fe3+(aq) + Mn2+(aq) + 4H2O(l) The above equation shows that one mole of manganate(VII) ions reacts with 5 moles of iron(II) ions in acid solution.
CuSO4 4. What is the molar mass for anhydrous (without water) copper(II) sulfate? 159.62 g/mol Result: Observation: Some gray white substances precipitated from the water in the crucible. Data: * Mass of purified crucible and lid 30.59g * Mass of crucible and lid and hydrate 31.57g * Mass of hydrate alone 31.57g- 30.59g = .98g * Mass of crucible and lid and dehydrate 31.11g * Mass of dehydrate alone .52g This lab shows that hydrates are made up of crystal solids and water,
Using 1 ml micropipette add 1.0 MR in each four 10 ml volumetric flasks. 3. Prepare following MR solution in four flasks: flask 1: add 5 mL pH 4 buffer (graduated cylinder) and fill to the mark with water flask 2: add 5 mL pH 5 buffer and fill to the mark with water flask 3: add 5 mL pH 7 buffer and fill to the mark with water flask 4: add 1 mL 0.01M NaOH and fill to the mark with water. 4. Record the spectrum for these four solutions in range 400-700 nm.
bioloQuiz 9 Chapter 10 Question 1 Wastes are part of blood True False 2 points Question 2 A hematocrit is the % of ________________ 1. leukocytes 2. eythrocytes 3. platelets 4. clotting factors 2 points Question 3 Normal hemotocrit is ___% erythrocytes of total volume 1. 50 2. 40 3. 30 4. 45 2 points Question 4 The protein in blood that regulates osmotic pressure and pH is albumin True False 2 points Question 5 All of the following are PLASMA blood proteins EXCEPT 1. albumin 2. hemoglobin 3. fibrinogen 4. globulin 2 points Question 6 Which element in hemoglobin binds oxygen 1. calcium 2. zinc 3. iron 4. iodine 2 points Question 7 How many red blood cells in blood and how many white blood cells?
Kyla Emerine Date of Experiment: April 15, 2015 Report Submitted: August 17, 2015 Title: Colligative Properties and Osmotic Pressure Purpose: To observing changes of colligative properties in freezing and boring points, by adding salt to a solution. Procedure: In this experiment I performed various procedures such as adding different amounts of salt to tap water that was freezing or boiling and observed how it changed the temperatures. Data Tables: Data Table 1. Dialysis Tubing Results Time: |Mass of Dialysis Tubing and Contents | 0 minutes |6.5g| 30 minutes |6.8| 60 minutes |7.2| Questions A. In your experiment, is the light corn syrup in the dialysis tubing hypertonic or hypotonic to the water?
Adjust the percent transmittance to 100% 4)our out the water in the cuvet, and fill with 2/3 of the reference solution. Read and record absorbance data. Read from lower concentration to higher concentration. 5)Continue to collect absorbance data for al reference and test solutions 6)Dispose of the contents of the cuvets. Data Tables #1 Reference Solutions for the Calibration Curve Sample [FeSCN2+] Absorbance Reference Solution #1 4x10-5 .2034 Reference Solution #2 6x10-5 .3028 Reference Solution #3 8x10-5 .3915 Reference Solution #4 1.0x10-4 .4908 Reference Solution #5 1.2x10-4 .5768 #2 Test Solutions Temperature - 21.9°C Sample [Fe3+] [SCN-] Absorbance Test Solution #6 1.0x10-3 2.0x10-4 .1002 Test
2) Percent recovery for isolation of benzoic acid % Recovery = mass of recovered material _________________________________ x100% mass of starting material = (0.43/1.01) x100% = 42.57% That concludes that the percent recovery is 42,57%. 3) Percent recovery for isolation of hydroquinone dimethyl ether % Recovery = mass of recovered material _________________________________ x100% mass of starting material = (0.16/1.01) x100% = 15.84% That concludes that the percent recovery is 15.84%. Table 2: : Experimental IR peaks compared to literature IR peaks for Benzoic acid Functional groups | Experimental peak (cm-1) | Literature peak (cm-1) | O-H | 3407-2563 | 3400-2564 | C=O | 1689 | 1689 | C-H |
Titration Aim Part A: To prepare a primary standard and use it to determine the concentration of a sodium hydroxide solution. Part B: To monitor the neutralisation of dilute vinegar by a standardised sodium hydroxide solution to determine the concentration of acetic acid in dilute vinegar. Equipment • 250mL volumetric flask • Oxalic acid dehydrate crystals • Beaker (150mL) • Small funnel • Phenolphthalein • Burette • Wash bottle with distilled water • Electronic balance • Pipette (25mL) • 2 x Beaker 50mL • Burette clamp and stand • Pipette filler • Spatula • Glass rod • pH meter and data logger • Standardised NaOH solution • Diluted vinegar (150mL diluted into 1L with distilled water) • Sample of 0.1mol/L sodium hydroxide solution • Magnetic stirrer with stirrer • 100mL measuring cylinder Method Part A: Preparation of Standard Solution 1. The molar weight (M) of oxalic acid dehydrate was calculated. 2.