EXPERIMENT: TECH 0704, Distillation, macroscale technique only, simple and fractional: Substitute a mixture of 25 mL ethanol and 25 mL water for the toluene/cyclohexane mixture. Record the temperature at 2 mL intervals of distillate. Use glass beads to pack the fractionating column. Construct a graph of temperature vs volume for each distillation in your lab notebook. Compare the efficiencies of the two distillation methods in your lab notebook.
You now have sao mL of a zinc iodide aqueous solution. On the label of the flask you write (there ca'n be many different possibilities): ( tl ;)'II I ! Exercise 2. Two students need zinc iodide that is in solution in the following amounts: Student 1 : 0.43 g of zinc
Abstract In this experiment we are explored the simple calorimetric estimate for the enthalpy of combustion of different alcohols. Our aim is to find out which alcohol is most efficient. Method First of all we drew up a table – this was what we used to record our results in. We then measured 100cm3 of water into a measuring cylinder and poured the water into steel we then recorded its temperature. We selected a spirit burner and recorded the name of the fuel into our table; we also included the mass of the whole burner.
Y-cable 125 _____________ 22175 Vat 13% extra Practice Test Two Candidate Name _________________ INTERNATIONAL ENGLISH LANGUAGE TESTING SYSTEM LISTENING SECTION TIME: 30 MINUTES INSTRUCTIONS: You must not open the booklet until you are instructed to do so. Write your name and registration number at the top of the page. You should attempt all questions. All recordings will be played only once. Write all your answers on the test paper itself.
A student calculated the theoretical yield of barium sulfate in a double replacement reaction experiment to be 1.35 g. When she filtered, dried and weighted her solid (precipitate), however, her yield was only 1.29 g. Calculate the student’s percent yield. 3. Before going to lab, a student reads in his lab manual that the percent yield for a difficult reaction to be studied was likely to be only 40% of the theoretical yield. The student’s pre-lab stoichiometric calculations predict that the theoretical yield should be 12.5 grams. What is the student’s actual yield likely to be?
Techniques to be practiced are: analytical balance, weighing by difference, volumetric glassware and significant figures. Procedure Part I * Form a group of 2-3 students * Obtain sodium carbonate in smallest beaker Part II * Add 10 mL of water to a beaker * Add small amount of sodium carbonate with spatula * Swirl solution to see if it dissolves * Add one drop of indicator and record the color of solution Part III * Complete 4 trials of various volumes of each of the three acid solutions. * Record the mass of sodium carbonated needed to react with the volume of each type of acid in a chart * Add one drop of indicator to each volume of acid before putting sodium carbonate into solution to observe reaction Part IV * Create tables containing the four solution volumes and mass of sodium carbonate required per volume * For each solution: * Find ratio of mass to volume for each trial * Compute average value of the ratio * Create a graph for each acid demonstrating mass per volume of acid solution. Draw best fit line through points and find the slope of that line * Also create one graph for each concentration of acid that displays the moles of acid in relation to the moles of
This led to an experiment which you can try for yourself and investigate the amount of carbon dioxide dissolved in different beverages and how much can be released at different temperatures. To do this experiment I used a few 16 ounce (454 milliliter) plastic bottles of Pepsi One (at room temperature) and an electronic scale that could hold 0.5 Kg and could be tared.Your chemistry teacher may have such a scale. First I put a bottle of the Pepsi One on the scale and pressed the "tare" button. This sets a 'zero' on the scale so that
On-line Science Simulations - Marble Chip Student Worksheet When hydrochloric acid is added to calcium carbonate (marble chips) carbon dioxide is evolved. In the experiment shown, 21.6 g of calcium carbonate is added to 200 cm3 of hydrochloric acid. The number of chips can be varied but the total mass is always 21.6 g and the volume of acid is always 200 cm3 but the concentration can be varied. The apparatus is placed on a balance that has been zeroed so that it always shows the same initial mass at the start of the experiment. During the reaction, carbon dioxide is evolved and the mass decreases.
Earn CE credit online: Go to http://www.nursingcenter.com/CE/NM and receive a certificate within minutes. INSTRUCTIONS Drill down with root cause analysis TEST INSTRUCTIONS • To take the test online, go to our secure Web site at http://www.nursingcenter.com/ce/nm. • On the print form, record your answers in the test answer section of the CE enrollment form on page 32. Each question has only one correct answer. You may make copies of these forms.
Used needles must never be re-sheathed, bent, cut or broken. Sharps must not be passed from hand to hand. After use: Sharps containers must not be filled above the “fill” line. Dispose of sharps immediately after use into approved box. Extra vigilance is required during emergency procedures.