The metal oxide was disposed of in the proper marked contained and the crucible was cleaned of any residue and rinsed with deionized water. Students determine the mass of copper metal produced from a given amount of copper oxide and plot this data for the entire class for each chemical method. Problem 10: When the element antimony, Sb, is heated with excess sulfur, a reaction occurs to give a compound containing only antimony and sulfur. This is because the magnesium not only reacted with the oxygen and the nitrogen in the air but also with the porcelain of the crucible. The crucible, lid and compound were heated for another 3 minutes.
Sorry, but copying text is forbidden on this website! After the lab, the inside of the crucible was black. They should divide mass by the atomic mass for each element. As trial 1 yielded no significant change in mass, trial 2 was conducted with the outcome being a significant change in mass. © Nuffield Foundation and the Royal Society of Chemistry Page last updated October 2015 This is a resource from the Practical Chemistry project, developed by the Nuffield Foundation and the Royal Society of Chemistry. Write your initials on a piece of paper towel to identify your sample.
You will need to pick up the Bunsen burner and move the flame around to heat every bit of the copper oxide. Two of each necessary material was gathered in order to conduct two trials at once. The experiment is also part of the Royal Society of Chemistry's Continuing Professional Development course:. Additionally, carrying electrons indirectly on ions is utilized, as seen through use of the vinegar. Combustion reactions always involve oxygen and are almost always exothermic. The crucible and lid were heated gently for 4-6 minutes until the bottom of the crucible became red. The slope of these plots provides a measure of the mass fraction of the copper oxide salt that is copper, and the empirical formula of the salt is determined for each chemical method using the slope.
The expected product is MgO, so the 1-to-1 mole ratio Mg to O in the product is all that is required. The net mass of the reactant side of the equation and the product side of the equation should be equal if the experiment is done correctly. In this experiment, students convert a copper oxide salt to copper metal by two chemical methods, one using methane gas in the solid state and one using aluminum metal in an aqueous solution. As vinegar is an acid donates a hydrogen ion , the hydrogen ions will cause the transfer of electrons between the iron and oxygen, in order to change the rate of reaction, as a solution that carries electricity electrolyte. These reactions involve a transfer of electrons, resulting in one compound gaining electrons and one compound loosing electrons. The compound formula defines the formula unit, the simplest whole-number ratio of positive and negative ions giving an electrically neutral unit. The final mass of the oxide is 3.
Precautionary steps :The flow of hydrogen gas must be continued throughout the heating. Solution: 1 Determine mass of one mole: 1. Never place anything hot on a balance. Thistle funnel dropper is opened to allow the acid to flow into the conical flask. The mass of the cooled crucible and lid was recorded using the electronic scale. The reason for waiting for the crucible to cool before weighing it was because at higher temperatures, the molecules inside are still active, causing the weight to be off. The crucible containing the magnesium was heated gently for 2-3 minutes.
To expel the nitrogen from the crucible, we added water to the mixture and heated it up. Lesson organisation This experiment is likely to take up to an hour, perhaps more to analyse the results. Alternatively, light a few around the room and students can light their own using a splint. The students will need access to matches or lighters to light their Bunsen burners. Under normal circumstances, room temperature, magnesium metal, Mg, reacts very slowly with the oxygen, O, in the air. Precautionary steps :The hot copper metal is allowed to be cooled in a stream of hydrogen gas.
Please know that it is now chemical waste and must be placed in the solid waste container. It is not really suitable for a class practical for students under the age of 14, but could be a useful demonstration. The tube is cooled down. In this lab, magnesium metal an element is oxidized by oxygen gas to magnesium oxide a compound. The purpose of this experiment is to find the empirical formula of a compound using whole numbers. Heating the product again causes the loss of water and conversion of the hydroxide to the oxide.
When the tube is cool, switch off the gas. A crucible and Bunsen burner will be used to heat magnesium metal to burning. Determine the empirical formula of the oxide. One sign of this reaction was the ammonia smell given off. What is the molecular formula of the compound? Pre-lab questions: No pre-lab questions were necessary for this experiment. What is the empirical formula of the antimony-sulfur compound? Find the empirical formula and the identity of this compound assume the empirical and molecular formulas are the same. .
During Trial 2, the magnesium was not properly burned off and caused the calculations to be off. Weigh with a chemical balance. The small amount of nitride that forms can be removed with the addition of water, which converts the nitride to magnesium hydroxide and ammonia gas. The sample was heated slowly and then the heat was intensified for 15-17 minutes. The crucible was then removed from heat and then cooled on the wire pad. Without oxygen, a fire cannot exist. The product is weighed once again.
The fire was started with the striker and the flame was adjusted to the height of the ring clamp. With this information they can calculate the formula of the copper oxide. The empirical is the simplest whole number ratio of the elements in that compound. What is the empirical formula of magnesium oxide? When the reaction of copper oxide is completed, brown copper metal is formed. If there is no 'pop' sound, then all hydrogen has been removed. Solution The empirical formula is the simplest whole-number ratio of atoms in a compound. Empirical Formulas and mol: The empirical formula is the simplest whole-number ratio of numbers of mols of atoms in one mol of a compound.