FC: Sunshine Christian Bilingual School | 11 Grade | Mr. Jose popoff | Stoichiometric Relationships lab report | Victor Ariel Vasquez October/29/2012
1: Introduction | In this lab report we will look for chemical reactions to determine a mole ratio and convert the measured masses to moles. | Goal Demonstrate the relationship between the moles of reactant and the moles of product in a chemical reaction.
2: Materials | balance beaker, 150 mL Bunsen burner crucible tongs evaporating dish hydrochloric acid (HCl), 6 M iron ring matches ring stand sodium hydrogen carbonate spatula test tube transfer pipet wash bottle watch glass, small weighing paper wire gauze
3: Procedure | 1. Prepare the materials. a) Clean an evaporating dish and rinse it with distilled water from a wash bottle. b) Using the crucible tongs, hold the evaporating dish in a well adjusted burner flame for several minutes to remove all the moisture. c) While the dish is cooling on the wire gauze, use a spatula to obtain some sodium hydrogen carbonate on a piece of weighing paper. d) After the dish is cool, measure its mass. e) Using the spatula, add about 3 g of the NaHCO3 to the evaporating dish while it is still on the balance. Record the combined mass of the dish and NaHCO3
4: 2. React the NaHCO3 with the HCl. a) Cover the evaporating dish with a small watch glass to keep materials from splattering out during the reaction. b) Obtain about 6 mL of 6 M HCl in a clean test tube. Gradually add the acid to the NaHCO3 with a transfer pipet or dropper. Allow the drops to enter the lip of the evaporating dish so that they flow down the side gradually.
5: c) continue adding the acid until the reaction stops. Do not add more acid than is necessary. Tilt the dish from side to side to make the acid reaches all of the solid. d) Remove the watch glass and, using a transfer pipet, rinse any spattered material from the underside of the watch glass with a small amount of distilled water. Be careful to wash all of the material into the evaporating dish so that no NaCl is lost.
6: 3. Boil off the water and determine the mass of the NaCl. a) Place your evaporating dish on a wire gauze that is supported by an iron ring stand. Heat the water boil over or you will lose some of the NaCl. b) Continue to heat the dish until most of the water has evaporated. Use an air bath as you did in before.
7: c) Remove the dish from the air bath and allow it to cool; then weigh it and record its mass. d) To make sure that all of the water has been driven off, reheat the dish and contents directly on the wire gauze. Let them cool and weigh them again. If this mass does not closely agree with the mass in step 3c, reheat, cool, and continue measuring the mass until you achieve a consistent measurement.
8: data | 1. Mass of evaporating dish: 54.3 g 2. Mass of evaporating dish plus NaHCl3: 57.3 g 3. Mass of evaporating dish plus NaCl-weighing 1: 2.1 g 4. Mass of evaporating dish plus NaCl-weighing 2: 1.9 g
9: 1. Write the balance equation for the reaction in this experiment. NaHCO3 + HCl = NaCl + h2o + co2 + H2O 2. How many grams of NaHCO3 reacted? 3.00 g 3. How many grams of NaCl were produced? 56.05 g 4. Calculate the number of moles of NaHCO3 that were used in the reaction. 0.04 moles
10: 5. Calculate the number of moles of NaCl that were produced in the reaction. 0.959 moles 6. Divide both of the mole amount (4 and 5) by the smaller of the two to give your experimental ratio between NaHCO3 and NaCl. x= x:1 7. What is the mole ratio between NaHCO3 and NaCl from the balanced equation? 0.1 moles
11: 8. What is your percent error? 0% Conclusion We conclude that if we are careful when you determine the masses, you experimental mole ratio will equal the theoretical mole ratio.
13: "I believe a leaf of grass is no less than the journey work of the stars." Walt Whitman
14: AT THE START of the Rattanakosin or Bangkok period in the late eighteenth century, when the capital was finally settled at Bangkok, an elephant kraal was established in Krabi by order of Chao Phraya Nakorn (Noi), the governor of Nakhon Si Thammarat, which was by then a part of the Thai Kingdom. He sent his vizier, the Phra Palad, to oversee this task, which was to ensure a regular supply of elephants for the larger town. So many followers emigrated in the steps of the Phra Palad that soon Krabi had a large community in three different boroughs: Pakasai, Khlong Pon, and Pak Lao. x | In 1872, King Chulalongkorn graciously elevated these to town status, called Krabi, a word that preserves in its meaning the monkey symbolism of the old standard. The town's first governor was Luang Thep Sena, though it continued a while as a dependency of Nakhon Si Thammarat. This was changed in 1875, when Krabi was raised to a fourth-level town in the old system of Thai government. Administrators then reported directly to the central government in Bangkok, and Krabi's history as a unique entity separated from the other provinces, had begun.
15: ANOTHER BEAUTIFUL SUNSET OFF KRABI POINT | November 11
16: ELEPHANTS AT PATARA FARM | November 12
17: LONGTAIL BOATS OFF THE COAST OF MAYA BAY | November 13
21: SWALLOW CAVES BY MAYA BAY | November 14
22: "The entire ocean is affected by a pebble." | Blaise Pascal
23: "I believe a leaf of grass is no less than the journey work of the stars." | Walt Whitman