The Formula Of Magnesium Oxide

2. The second source of error in the lab is when opening the lid of the crucible which allowed smoke of magnesium oxide to escape. During the lab, we removed the lid a couple of times to allow oxygen to enter the crucible so the magnesium reacts with the air to form magnesium oxide. However, the smoke could have easily escaped from the crucible because of the strong force of heat from the laboratory burner. This could have affected the lab results by decreasing the final mass when some of the product have escaped.

Materials:Magnesium stripCrucibleCrucible coverClay triangleIron ringRetort standTongsBalanceBunsen burnerProcedure:1.obtained a strip of magnesium between 30-40 cm long2.coiled magnesium strip into a tight roll3.measured the mass of the crucible and cover4.Added the magnesium strip to the crucible and measured the

The first experiment is about the combustion of magnesium after which the ash is formed.

The purpose of this lab was to find the empirical formula of magnesium oxide. The empirical formula of a compound is the simplest formula based on the number of different atoms in that compound. In this lab, the student burned magnesium, in the form of a ribbon, which bonded with oxygen to form magnesium oxide. The mass of oxygen was calculated by subtracting the mass of the magnesium ribbon from the mass of the magnesium mass. The masses of magnesium and oxygen were converted into moles, which was used in the calculation of the empirical formula.

The aim of the lab was to determine the molar enthalpy of the combustion of magnesium using values from reactions between magnesium and magnesium oxide in hydrochloric acid solution using Hess’s Law and Calorimetry. The calculated molar enthalpy of the combustion of magnesium from this experiment was -633.6KJ/mol. This result was found by putting a known mass of magnesium metal as well as magnesium oxide powder into a concentration of HCl. Firstly, a styrofoam calorimeter was used to determine the standard reaction temperature of magnesium metal and hydrochloric acid. Next, calorimetry was again used to determine the reaction temperature of magnesium oxide and hydrochloric acid. Lastly, the thermochemical equations for the two

The purpose of this lab was to test the law of definite proportions for the synthesis reaction of combusting magnesium. In this lab, the polished magnesium ribbon was placed in covered crucible and was heated in order for it to react with Oxygen presented in air and in water provided. The result showed that Magnesium oxide formed through chemical reaction was made up of 60.19% magnesium and 39.81% oxygen, which is approximate proportion of both particles in every Magnesium oxide compound. From this lab it can be concluded that the law of definite proportion stating that the elements in a pure compound combine in definite proportion to each other is factual.

    In this lab, a calorimeter was used to find the enthalpy of reaction for two reactions, the first was between magnesium and 1 molar hydrochloric acid, and the second was between magnesium oxide and 1 molar hydrochloric acid. After the enthalpy for both of these were found, Hess’ law was used to find the molar enthalpy of combustion of magnesium, using the enthalpies for the two previous reactions and the enthalpy of formation for water. The enthalpy of reaction for the magnesium + hydrochloric acid reaction was found to be -812.76 kJ. The enthalpy of reaction for the magnesium oxide + hydrochloric acid reaction was found to be -111.06 kJ. These two enthalpies and the enthalpy of formation for water were manipulated and added together using Hess’s law to get the molar enthalpy of combustion of magnesium. It was found that the molar enthalpy of combustion of magnesium was -987.5 kJ/mol. The accepted enthalpy was -601.6 kJ/mol, which means that there is a percent difference of 64%. This percent difference is very high which indicates that this type of experiment is very inefficient for finding the molar enthalpy of combustion of magnesium. Most likely, a there are many errors in this simple calorimeter experiment that make it inefficient for finding the molar enthalpy of combustion of magnesium.

About 80 mL of HCl was obtained and mixed with phenolphthalein. Using a LabQuest unit and Gas Pressure Sensor kit, the HCl mixture was added to the flask with the magnesium ribbon and allowed to react. When reaction was complete, the change of temperature and gas was recorded. This procedure was repeated for different masses of magnesium ribbon (masses found on page 89 of the lab manual). After the completed procedure, moles of H₂ produced in each trial were calculated. (The actual procedure can be found on pages 87-89 of the lab manual)

Using elemental analysis to determine the percent mass composition of each element in a compound is the first step in creating an empirical formula. There are many different types of elemental analysis, but in this experiment gravitational analysis and Beer’s Law are used. Elemental analysis is first used to find the moles of each element, then converted to mass, and then the percent mass of the element in the product is found (2).

The purpose of this experiment is using Compleximetric titration and EDTA to determine the concentration of Mg2+ in solution; and also calculating the percent by mass of MgO in the unknown sample. This procedure results no significant deviations.

Because it is dangerous to burn magnesium, it is not possible to directly record heat change. Our lab team suggests an indirect way of determining the heat of combustion for magnesium. To accomplish this, we need to perform two separate trials. One uses a solid (powder) version of MgO, while the other uses Mg ribbon. With the results from these, we can use Hess’ Law to determine q=∆H. This provides both a safe and successful way of indirectly determining the heat of combustion for magnesium.

Based on the data collected, the mass of the magnesium, mass of oxygen, number of g atoms of magnesium, and number of g atoms of oxygen can all be determined with calculations. During the lab the data collected included the mass of an empty crucible, and the mass of the crucible and magnesium. To calculate the mass of the magnesium, you subtract the mass of the crucible from the mass of magnesium and the crucible. To find the mass of the oxygen, you subtract the mass of the crucible and magnesium from the mass of the crucible and oxide . The next calculation that needed to be completed includes the number of moles of the magnesium and the number of moles of oxygen. To calculate the number of moles of magnesium, the mass in the experiment and

The volume of carbon dioxide gas produced from a reaction was measured in order to determine what carbonate sample was used. A gas assembly apparatus was used to capture the gas from a reaction between an unknown carbonate and 6M hydrochloric acid; three trials were performed. The mass of the unknown carbonate was determined, and the reaction occurred in a test tube. The volume of gas produced by the reaction was measured, and the partial pressure of carbon dioxide was calculated after the partial pressure of water vapor was determined using Dalton’s Law of Partial Pressures. The percent mass of carbon dioxide gas was then calculated, and the average mass percent was compared to the table of known carbonates. It was concluded that the unknown carbonate sample used in the reaction was magnesium carbonate.

5.3 mL of bromobenzne and 15 mL of anhydrous ether was then placed into the separatory funnel and was shaken and vented in order to mix the solution. Half of the bromobenzene solution was added first into the round bottom flask and as soon as a color change was observed, the remaining half of the bromobenzene was added drop wise into the round bottom flask. The mixture was then refluxed on a heating mantle for 10 minutes until most of the magnesium has been consumed.

7. When the crucible cooled down so that one was able to hold it, the