In the first part, five 100 mL flasks of 5 mL ligand solution, 5 mL 2 M sodium acetate, 4 mL 3 M NH2OH, and 1-5 mL Fe2+ solution are diluted with water. The absorption spectrum for varying concentrations of Fe2+ are measured using a spectrophotometer and the data is graphed in Excel. The slope of the line is ε in the Beer-Lambart equation A = εcl. In the second part of the experiment, eleven flasks containing diluted stock solutions of Fe2+ and ligand are mixed with 5 mL 2 M sodium acetate and 4 mL 3 M NH2OH and diluted with water. The absorption spectrum is measured using a spectrophotometer and the data is graphed in Excel.
c. Prepare the solution by dissolving 38.90 grams of ZnI2 with 500 mL of water. d. 0.0125/0.25 = 0.05 L = 50 mL. This produces 0.0125 moles of ZnI2 5. Exercise 5: a. (0.125)(0.1) = 0.0125 moles of solute b. Pour 50 mL of the stock solution to get the number of moles needed.
Conclusion 10 Grams of Potassium chlorate when decomposed produces 3.915576 grams oxygen gas and 6.083363 grams potassium chloride Atomic Weight of Magnesium Introduction In this lab we will determine the atomic weight of magnesium by measuring the amount of hydrogen gas evolved when hydrochloric acid reacts with magnesium. The reaction is as follows: Mg + 2HCl -> H2 + Mg2+ (aq) + 2Cl- (aq) There is a one to one relationship between the number of moles of hydrogen gas evolved and the
(2 points) Mg(s) + 2 HCl(aq) → H2(g) + MgCl2(aq) 2. Determine the partial pressure of the hydrogen gas collected in the gas collection tube. (3 points) partial pressure H2 = total pressure - vapor pressure of water = 746mmHg - 19.8mmHg = 726mmHg 3. Calculate the moles of hydrogen gas collected. (4 points) n = 125 4.
1. 25 cm3 of a solution of 0.1 moldm-3 NaOH reacts with 50 cm3 of a solution of hydrochloric acid. What is the molarity of the acid? 2. 25.0 cm3 of a 0.10 moldm-3 solution of sodium hydroxide was titrated against a solution of hydrochloric acid of unknown concentration.
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.
Observing Changes – Materials & Procedures Materials Water Copper (II) sulphate (Powder) Copper (II) sulphate solution Iron nail Sodium carbonate Hydrochloric acid Magnesium ribbon Flame (candle) Sugar Aluminum foil Test tubes Test tube rack Tongs Medicine dropper Spoons Beakers Safety goggles Scoopulas Procedures Water and Copper (II) Sulphate Procedure 1. Add a small amount of solid copper (II) sulphate to a test tube with a scoopula. Record the physical properties. 2. Write a hypothesis on what you think will happen when water is added.
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.
CaCO3 + 2HCl -----CaCl2 + CO2 + H2O ( Volume of acid added (L) ) (1.0mol/L) = moles acid added. Moles acid added - moles base added = moles acid that reacted. Moles of acid that reacted / 2 = moles CaCO3 present in sample. Final answer % CaCO3 3. Put exactly 5.0 mL of water in the 10.0 mL graduated cylinder.