After approximately four minutes without blood containi … ng oxygen, I'm sure you know , brain cells begin dying. From these quantities, find the experimental percentage of oxygen in potassium chlorate. This experiment is divided into two parts, thus having dipartite objectives for the whole experiment. The flame was waved under the crucible for 2 minutes. The foam has holes in it and appears moist. The Bunsen Burner was turned off.
The flame was placed directly under the crucible until hot and glowing. Using the initial mass of magnesium, calculate the moles of oxygen and then moles of magnesium oxide produced. Mass of clean dry crucible 22. After cooling, determine the mass of the crucible, contents and cover. Sir Davy was able to isolate potassium using electrolysis.
Potassium chlorate is also used in some formulas of gunpowder, generally replacing the less powerful potassium nitrate. Discard all test tube waste in the container provided. The data could then be inaccurate. These ionic bonds also have other properties which will affect my investigation, I must be aware of these properties for greater accuracy in my method. When cooled, weigh the crucible with the cover indirectly. A fire on the space station Mir was also traced to this substance. Remember that most items look exactly the same whether they are hot or cold.
Calculate the mass of water produced from the reaction of 24. Potassium chlorate will decompose into oxygen and potassium chloride. Any help would be greatly appreciated. D Set the container and its contents aside while you complete your calculations. MnO2 was added in the crucible. The percentage by weight of any atom or group of atoms in a compound can be computed by dividing the total weight of the atom or group of atoms in the formula by the formula weight and multiplying by 100.
It was discovered by Sir Humphrey Davy in England, in 1807. A positive test is indicated by the formation of a white precipitate. Potassium chlorate decomposes into oxygen, and when something that could burn, such as a gummy bear, is added to it, i … t rapidly combusts, driving the decomposition forward. Be sure to use the same beaker for each weighing. The safe performance of this reaction requires very pure reagents and careful temperature control. One mole of copper has a mass of 63. The mass of the residue after heating is 3.
If 386 mL of oxygen at 41 degree centigrade and 97. Upon analysis of this mixture, would you obtain a larger or smaller mass percent of oxygen than you would for an equal mass of pure sample of potassium chlorate circle one? We will test this theory. I think one could be that the masses used in calculating the theoretical percentage of oxygen were all rounded off. Make sure the mass is within 0. Suppose that the reaction described above produces 4.
After heating to a constant weight, the white ring of foam appears dry and powdery. Heat, strongly, a second time for about 5 minutes, cool and weigh. When calculating molecular weight of a chemical compound, it tells us how many grams are in one mole of that substance. Scale weight alone does not necessarily mean that an individual is lean or fat compared to another individual. Potassium chlorate is often used in high school and college laboratories to generate oxygen gas; it is a far cheaper source than a pressurized or cryogenic oxygen tank. The actual yield of O 2 measured by subtraction was 0.
The Bunsen Burner was lit. When heating a solid in a test tube, tip the tube until it is almost horizontal and tap it carefully until the contents are distributed over the lower half of the length of the tube, as shown in Figure 1. Potassium chlorate is used also as a pesticide. Specifically, the residue will be tested for the presence of chloride ions by the addition of nitric acid and aqueous silver nitrate. In this laboratory exercise you will decompose this compound by heating, and from the data obtained determine the percentage of oxygen by weight in the compound. Part A: Mass Percent of Oxygen in Potassium Chlorate The following steps should be carried out for two separate samples of potassium chlorate. If the test tube is equipped with a one-holed stopper and hose, warm oxygen can be drawn off.
Calculate the mass g of oxygen in the mixture. Spill it onto your skin, and it would leave a terrible burn. Record the mass of the container and its contents. If the solid does not dissolve completely, decant the clear part of the solution into a clean test tube, labeling this 1 instead. One way to express the proportion each of element in a compound is as a percentage by mass, or mass percent. Although the brain constitutes only 2 percent of our body mass, it uses 20 percent of the oxygen. My question is this: Given that the theoretical yield was 39.