% Composition By Mass of Oxygen in Potassium Chlorate Objective: The purpose of this lab was to calculate the percent composition by mass of oxygen in potassium chlorate. Procedure: 1.The mass of the crucible and the cover was measured. 2.KClO3 was added to the crucible. 3.The mass of the crucible, cover and KClO3 was measured. 4.MnO2 was added in the crucible. 5.The mass of the crucible, cover, KClO3 and MnO2 was measured. 6.The Bunsen Burner was lit. 7.The covered crucible was placed over the flame of the Bunsen Burner using a ring stand. 8.The flame was waved under the crucible for 2 minutes. 9.The flame was placed directly under the crucible until hot and glowing. 10.The Bunsen Burner was turned off. 11.The mass of the covered crucible was measured once cooled. Theory: Mass of 2KClO3 - Mass of 2KCl = Mass of 3O2 Mass of KClO3 = Mass of crucible, cover and KClO3 (Step # 3) - Mass of crucible and cover (Step # 1) Mass of O = Mass of crucible, cover, KClO3 and MnO2 after heating (Step # 11) - Mass of crucible, cover, KClO3 and MnO2 before heating (Step # 5) % composition= __Mass of O_ x 100 Mass of KClO3 Data: Mass of crucible and cover ~ 26.40g Mass of crucible, cover and KClO3 ~ 28.59g Mass of crucible, cover, KClO3 and MnO2 ~ 29.55g Mass of crucible, cover, KClO3 and MnO2 after heating ~ 28.60g Calculation: Mass of KClO3: 28.59g - 26.40g = 2.19g Mass of O2: 29.55g - 28.60g = 0.95g % Composition by mass: _(29.55g-28.60g) x 100 = 43.40% (28.59g-26.40g) Theoretical: __(3x16g)____ x 100 = 39.2% (39.1g + 35.5g + (3x16g) .392 x (28.59g - 26.40g) = .859g Discussion: The % composition by mass of oxygen in Potassium Chlorate was found to be 43.4%. The error analysis ~ _ç.
Before the penny is weighed, there is still acid on the penny, so in order to get the actual copper mass, the penny has to be washed. When getting the penny out of the beaker, the solution must be diluted because the acid can not be physically touched. Now, the penny has to be dried by a bunsen burner to ensure water molecules won’t be part of the weight of copper. The penny will lightly touch the fire, and once the whole penny is dried, the penny is weighted to get the mass of copper. The mass of copper is subtracted from the total mass of the penny to get the mass of zinc. Now the weight of copper and zinc is collected, the percent composition can be
The mass of Mg + the mass of O2=mass of MgxOx. Knowing the mass of
The objective of part A was to determine the rate of the substitution reaction between 1-Chlorobutane and KOH. This information was obtained by using the titration method to record the concentration of KOH over a given amount of time. To start this procedure, 1-Chlorobutane was added to a round bottom flask, which was connected to a reflux apparatus. Once it was observed that reflux had started the KOH was added with EtOH; this is the start of the reaction. The aliquot was then titrated with 0.100 M HCl and the concentration was noted at each interval. By graphing the data one can determine the order of the reaction and the rate of the leaving group. This data will provide the type of the reaction, whether it is SN1 or SN2.
Scheidt, Jennifer L., and Denis M. Calandra. “CliffsNotes on The Crucible.” CliffsNotes.com. CliffsNotes. 2010. Web. 18 Sep 2011.
* Note the mass down in the table at the end of the first page.
Using the previously calculated Kf, the molar masses of unknown substances A, C, and D were able to be calculated. However, given that the original Kf was slightly larger than the theoretical value, the molar
Objective: The objective of the experiment is to determine what factors cause a change in speed of a reaction. It is also to decide if the change is correlated with the balanced equation of the reaction and, therefore, predictable. To obtain a reaction, permanganate, MnO_4^(1-), must be reduced by oxalic acid, C_2 O_4 H_2. The balanced equation for the reaction is:
Potassium is an element on the periodic table that is symbolized by the letter K. The atomic number of this element is 19. At room temperature this element is a solid. Potassium can be found in two forms: either pure or compounds. Pure potassium is described as a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive in water However, Potassium forms many compounds such as Potassium chloride, which is the most common potassium compound (Gagnon, 1). This form of Potassium is especially used in fertilizers as a salt substitute. Another potassium compound is Potassium hydroxide, which is used to make soap, detergents and drain cleaners. Potassium carbonate is used to make some types of glass and soaps. This is also obtained as a byproduct of ammonia. Lastly, Potassium superoxide can create oxygen from water vapor and carbon dioxide. An example of this reaction is “2KO2 + H2O + 2CO2 => 2KHCO3 + O2” (Gagnon, 1). Gagnon also says, “it is used in respiratory equipment and is produced by burning potassium metal in dry air. Potassium nitrate (KNO3), also known as saltpeter or nitre, is used in fertilizers, match heads and pyrotechnics” (Gagnon, 1). Sir Humphrey Davy discovered this element in England in 1807 (Helmenstine, 1). Steve Gagnon, maintainer of the Jefferson Lab website page says, “Sir Humphry Davy first isolated metallic potassium in 1807 through the electrolysis of molten caustic potash (KOH)” (Gagnon, 1). Gagnon also writes, “a few months after discovering potassium, Davy used the same method to isolate sodium. Potassium can be obtained from the minerals sylvite (KCl), carnallite (KCl·MgCl2·6H2O), langbeinite (K2Mg2(SO4)3) and polyhalite (K2Ca2Mg(SO4)4·2H2O). These minerals are often found in ancient...
Ever since the early days of human civilization, people gazed up into the sky into the beyond, wondering what secrets the stars held from them. The mass of stars compared to our sun is a frequented question by many astronomers. The answer lies within the luminosity and mass of the star. There are 2 different ways humans can calculate the mass of stars, both using luminosity. One way is to calculate luminosity with radius and temperature of the star being observed. Another much simpler way is to convert apparent magnitude, the brightness of the star observed from earth, to absolute magnitude, the brightness of stars when they are all lined up at the same distance, then convert into luminosity. Once luminosity is calculated, the mass — luminosity relation can be used to find mass.
The mixture was poured through a weight filter paper and Sucrose washed with a 5ml of dichloromethane. The resulting solid was left in a breaker to dry for one week, to be measured. Left it in the drawer to dry out for a week and weighted it to find the sucrose amount recovered amount.
The purpose of this experiment is to use our knowledge from previous experiments to determine the theoretical, actual, and percent yields of the lead chromate from the reaction of solutions of potassium chromate and lead nitrate (Lab Guide pg. 83).
Our procedure though was not without its mistakes. These mistakes are vital because they affect the data we conclude. Theoretically, according to the balanced chemical equation, for every mole of hydrated cobaltous chloride that is being heated, the decomposition ensures that the compound decomposes into one mole of cobalt(II) chloride and six moles of gaseous water vapor. Thus, in theory we should lose the mass equal to six moles of water vapor in each trial. Unfortunately, this is not the case because we don’t have perfect lab conditions and factors such as the time heated, utilization of the same crucible, and the inconsistency of magnitude of the flame from the Bunsen burner all contribute to differences in mass percent change for each
•Percent of oxygen in magnesium oxide = MgO = 24.3 g + 16 g = 40.3 g/mol
Aim: The aim of this experiment was to determine the empirical formula of magnesium oxide.
Based on your experiments what is the formula of the colorless gas that is released when heating the malachite?