For every 20 drops of solution you will add 0.1g of zinc to the new test tube. Repeat steps 3 and four until the solution is clear. If there ever exists too little of the solution to get enough drops, add up to 1mL of distilled water to the solution. 4. Once the solution is clear, retrieve at least ten drops of the solution and place them in a new test tube.
(0.050) (0.1) = 0.0083 moles b. Pour 8.3 mL of the stock solution to get the amount needed. c. Measure out 8.3 mL in a graduated cylinder 8. Exercise 8: a. 41.8 mL are used b. 0.00079 moles EDTA4- c. 0.00079 moles ZnI2 d. 0.0517 grams of ZnI2 are in the sample e. 0.0517/0.237= 21.8% f. Error Is 6.34% Lab Report: Part 1: In this lab we used the following supplies: * Zinc Iodide * Na2H2EDTA(s) * Calmagite indicator solution * pH 10 buffer solution * 6M Acetic Acid * Unknown Zinc Compound The main purpose for this part of the lab was to determine the amount of zinc ion in a sample of ZnI2 by titration.
NaOH solution would be in excess and thus prepare 1 M of HNO3 solution in burette, which will be used in back-titration. 4. Determine the end point of the back-titration when NaOH solution changes its color into pink. Record the results of at least three titrations. (Make a rough titration first).
5. Potassium hydroxide solution: Use 0.01 M potassium hydroxide, 0.56 g/L. 6. Ammonium hydroxide solution: Add water to 10 mL of concentrated ammonium hydroxide solution to make 82 mL of a stock solution. Use 10 mL of the stock and dilute to 1 L with distilled water.
Add a quarter spatula of copper (II) oxide and warm the solution gently to the 4th test tube and record observations. 7. To the 5th test tube, add 3cm3 of ethanol a couple of drops of conc, sulphuric acid and warm gently. Pour the resulting mixture into 30cm3 of sodium carbonate solution to remove excess acid and smell and record observations. Experiment 2 Time | Observations | 5 minutes | Bubbled like sugar | Once salt water was added | Turned soapy white and thick | Equation: METHOD 1) Put 2 cm3 of castor oil into a 250 cm3 beaker and add 10 cm3 of 5mol.dm-3 sodium hydroxide from a measuring cylinder.
Add stir bar to 10 mL Round-bottom flask then add 0.360 g of borneol, 1 mL dry acetone and 0.30 mL glacial acetic acid. Put a air condenser and place in sand bath. Exact amount added was 0.358g of borneol. A pipet was used for acetone and acetic acid. 2.
As before, test the egg in each cup, starting with the lowest salt concentration. In which cup did the egg float first? 9. If you want, make another dilution series, with even smaller steps, to improve the precision of your estimate. 10.
Add color indicator 4. Obtain a burette and fill it with NaOH 5. Titrate the 10 mL with NaOH until it turns pink 6. Weigh a dry funnel with a filter paper and record the weight 7. Obtain an Erlenmeyer flask that has a vacuum opening and attach the vacuum tube to it 8.
b) What is the molar concentration (molarity) of ethanol in the wine? Chem 131 Solution Stoichiometry and Gas Law Problems Page 1 Problem 3 As part of some research for the product Alka-Seltzer, a researcher combines 0.840g sodium bicarbonate with 100.0 mL of 0.0500 M citric acid (H3C6H5O7). a) Write the molecular, complete ionic, and net ionic equations for this reaction (assume that each molecule of citric acid is completely neutralized). b) If the dry gas that the student actually collects occupies a volume of 0.196 L at 25°C and 1.00 atm pressure, what is the percentage yield of this reaction? c) The researcher
Recrystallise the crude ester from methanol using a quantity of hot solvent approximately twice the minimum required for complete solution (This is to ensure that the phenyl benzoate does not separate until the temperature of the solution has fallen below the melting point of the ester). Phenyl benzoate separates as colourless crystals. 5. Determine the melting point of the product. Results : Yield (mass in gram) = __________________0.128 g_____________________ Melting point of pure phenyl benzoate (OC) = ___________70O______________ Melting point of your phenyl benzoate (OC) = ___________69O______________ Questions : 1.