Determining the Relative Atomic Mass of Lithium An experiment has been carried out to determine the relative atomic mass of Lithium by using two different types of methods The first method that was carried out was to determine the volume of Hydrogen produced. In this experiment a fixed amount of Lithium was used, in my case it was 0.11g. At the end of this experiment, the volume of Hydrogen gas I collected was 185cm³. Then using the solution of lithium hydroxide made from experiment one, I used it in the titrating experiment, to find out the total volume of Hydrochloric acid used to titrate the lithium hydroxide. RESULTS TABLE Experiment Initial Volume ( cm³) Final Volume ( cm³) Total volume Of HCl used ( cm³) Rough 0.2 30.3 30.1 1 6.3 35.8 29.5 2 2.7 32.0 29.3 Average 29.6 CONCLUSION Method 1 [IMAGE]2Li (s) + 2H20(l) LiOH(aq) + H2(g) Number of moles of Hydrogen. Volume of hydrogen gas was 185 cm³. Weight of Lithium was 0.11g. N = __V__ _185_ = 0.0077 MOLES 24000 24000 Number of moles of Lithium. 2Li : H2 2 : 1 ratio 0.0154 : 0.077 Lithium = 0.0154 moles Relative atomic mass of Lithium. Ar = MASS _0.
Strontium was discovered by Adair Crawford, an Irish chemist, in 1790 while studying the mineral witherite (BaCO3). When he mixed witherite with hydrochloric acid (HCl), he did not get the results he expected. He assumed that his sample of witherite was contaminated with an unknown mineral, a mineral he named strontianite (SrCO3). Strontium was first isolated by Sir Humphry Davy, an English chemist, in 1808 through the electrolysis of a mixture of strontium chloride (SrCl2) and mercuric oxide (HgO). Strontium reacts vigorously with water and quickly tarnishes in air, so it must be stored out of contact with air and water. Due to its extreme reactivity to air, this element always naturally occurs combined with other elements and compounds. Strontium is very
Lithium has an atomic number of 3, and an atomic weight of 6.94. In general, lithium is more stable than hydrogen, and slightly less stable than nitrogen, carbon, and oxygen. When looking at chemical ion properties, it is useful to consider three main characteristics: the size, or radius, of the ion, the charge, and the ion's electron affinity. Lithium has a similar charge to radius ratio to that of magnesium, which is in group IIA of the periodic table, and so chemists say that the two elements are "chemically similar.
The first step that we took to accomplish our goal was to put on our safety goggles and choose a lab station to work at. We received one 400ml beaker, one polyethylene pipet, two test tubes with hole rubber stoppers, two small pieces of magnesium (Mg), one thermometer and a vial of hydrochloric acid (HCl). We took the 400ml beaker and filled it about 2/3 full of water (H20) that was 18 OC. Then we measured our pieces of Mg at 1.5 cm and determined that their mass was 1.36*10-2 g. We filled the pipet 2/3 full of HCl and poured it into one of the test tubes. Then, we covered the HCl with just enough H2O so that no H2O would be displaced when the stopper was inserted. After inserting the stopper, we placed the Mg strip into the hole, inverted the test tube and placed it in the 400ml beaker. HCl is heavier than H2O, so it floated from the tube, into the bottom of the beaker, reacting with the Mg along the way to produce hydrogen gas (H2). We then measured the volume of the H2, cleaned up our equipment and performed the experiment a second time.
In this experiment, there were several objectives. First, this lab was designed to determine the difference, if any, between the densities of Coke and Diet Coke. It was designed to evaluate the accuracy and precision of several lab equipment measurements. This lab was also designed to be an introduction to the LabQuest Data and the Logger Pro data analysis database. Random, systematic, and gross errors are errors made during experiments that can have significant effects to the results. Random errors do not really have a specific cause, but still causes a few of the measurements to either be a little high or a little low. Systematic errors occur when there are limitations or mistakes on lab equipment or lab procedures. These kinds of errors cause measurements to be either be always high or always low. The last kind of error is gross errors. Gross errors occur when machines or equipment fail completely. However, gross errors usually occur due to a personal mistake. For this experiment, the number of significant figures is very important and depends on the equipment being used. When using the volumetric pipette and burette, the measurements are rounded to the hundredth place while in a graduated cylinder, it is rounded to the tenth place.
7.The covered crucible was placed over the flame of the Bunsen Burner using a ring stand.
Chemistry is a science that makes measurements and use data to draw conclusions. Although chemistry is about measurements all data can have a margin of error if one does not correctly follow procedure of the lab. Error may also occur even if everything is done correctly. In this experiment, you will be finding the error within certain calculations using raw data, and the determination error which will allow you to find the density of different substances. To calculate error in the experiment we will be using two terms precision and accuracy.
* In method (1), due to the oil that lithium is stored in, not only
relative mass to a substance’s buoyancy. With identical volumes of 50 milliliters, it was found
Scientists ranging from James Clerk Maxwell and Max von Laue have been claimed to be true discovers of the Mass-Energy Equivalence, which has popularly been credited to Albert Einstein’s “Theory of special relativity” back in 1905. There has been many controversies, but in conclusion Einstein is the official claimer.(Ball, P. (n.d.). The equation proved that energy and matter are linked. This was only one of the major breakthroughs that Einstein made in 1905 and his best work was yet to come in later years.
Moles Volume HCl Volume Water 2 M 10 cm 3 0 cm 3 1.5 M 7.5 cm 3 2.5 cm 3 1 M 5 cm 3 5 cm 3 0.5 M 2.5 cm 3 7.5 cm 3
3 cm of magnesium ribbon generally has a mass of 0.04 g and yields 40 cm3 of hydrogen when reacted with excess acid. 50 cm3 of 1M hydrochloric in this experiment is in excess.
"A periodic table is an arrangement of elements in which the elements are separated into groups based on a set of repeating properties." Basically it shows us all known elements in the world. For one to read the periodic table he should beware that the atomic number comes first in the square , and referring to the atomic number its the number of protons found in the nucleus of an atom. Following the atomic number is the symbol, which is usually the abbreviation of the element's name. For example Carbon is referred to as " C". Then, the element’s name is shown right after the symbol. Lastly, there's the mass number, which is the number of protons and neutrons in the nucleus of an atom. So simply for us to find the number of protons we automatically
Firstly, we need to keep the chemical at a constant concentration. So, in this experiment we have chosen to keep hydrochloric acid at a constant concentration (5cm3). We could have, however, used Sodium Thiosulphate as a constant, but we had chosen to use Hydrochloric acid. Next, we must make sure that the solution is kept at a constant volume throughout the experiment. If the volume is different, then it could give different results if it was at a constant volume.
The purpose of this experiment is to use our knowledge from previous experiments to determine the exact concentration of a 0.1M sodium hydroxide solution by titration (Lab Guide pg.141).