Magnesium Ribbon Essay

2. When the magnesium ignited, removed it from the flame and held it over an evaporating dish or a pyrex watch glass until the metal had burned completely. Let the product fall into the evaporating dish.

Step 4: Place the test tubes into separate coffee cups to maintain the upward position. Add 2 mls of the catalase solution to each of the test tubes and then place tubes1, 2, and 3 in the conditions described above. For test tube 4, fill the coffee mug half full of boiling

H. How would you prepare 10 mL of a 0.25M HCl solution if 1M HCl was available? How much

12.Stir then pour 2.5ml of the enzyme mixture into one of the test tubes not allowing any water from the saucepan into the test tube.

* By using the dropper and measuring cylinder, 3ml of 1% lipase was added into the test tube

To keep a fair test I will have to look into all the variables surrounding the experiment and only change the variable that I am testing on. The other variables are the temperature of the acid at the beginning, the volume of acid, the surface area of the magnesium strip, the length of the magnesium strip and if the magnesium strip is cleaned or not.

Hypothesis: If the concentration of sulphuric acid (mol L-1) is increased, then the time taken for the magnesium to dissolve should decrease.

To see if the concentration of hydrochloric acid will increase the rate of the reaction between magnesium ribbon and hydrochloric acid.

Collect 25 mL of 0.1 M of hydrochloric acid and 2 cm of Magnesium ribbon. Place hydrochloric acid into Petri dish.

4.Measure 35mL of warm water and add them into each of the 4 test tubes at about roughly the same time. It is essential that the water is warm. Do not seal the test tube.

Next, add concentrated HCl drop wise until the litmus paper indicates that it is acidic. During this procedure, I added to much HCl because many CO2 gas bubbles evolved. This error in the experiment will cause the recovery % to be lower.

The ribbon is not. The crucible is heated for another 10 minutes. Step 9 is repeated until the ribbon become whitish. Then the crucible is allowed to cool.

Test tube 1 should have .04 g of benzophenone, test tube 2 should also have .04 g of benzophenone, etc., up to the fourth test tube.

Table #1 shows that the length of the sample of magnesium ribbon given was 1.67 cm (to 3 significant numbers), the barometric pressure (total pressure) was 95.81 kPa, the room temperature was 24.9 °C, and the measured gas volume converted from 24.72 mL to L was 0.02472 L. Then, the pressure of H2 was found by using Dalton’s Law of Partial Pressure, using the equation Ptotal = PH2+ PH20., found on Table #2 Part A. The pressure of H2O, 4 kPa, was determined by using Table H Vapor Pressure of Four Liquids on the Reference Table for Chemistry. Then, the pressure of H2O, 4 kPa, was subtracted from the total pressure, 95.81 kPa, to find the pressure of H2, 91.81 kPa. Next the mass of the sample of magnesium was found, shown on Table #2 Part B, given that the mass of Mg = 0.0100 g/cm. It was calculated that the mass of Mg per length found was 0.0167 g. Afterwards, the mass of Mg was converted to moles, using 3 significant numbers, shown in Table #2 Part C. The calculations shows that the number of moles of Mg found was 0.000687. Next, the mole ratio of Mg to H2 produced was determined by writing a balanced equation for the reaction, found on Table #2 Part D. The mole ratio of Mg to H2 produced was 1:1. Then, the number of moles of H2 produced (using 3 significant numbers) was found by using stoichiometry, shown on Table #2 Part E. The number of moles of H2 produced

2cm of a solution was tested and added 2 cm of 10% of potassium hydroxide solution and the test tube was shaked.