Lab Report Essay Example

Lab Report Essay LAB REPORT FOR EXPERIMENT 3 COPPER CYCLE OLANREWAJU OYINDAMOLA Abstract This experiment is based on copper, to synthesize some copper compound using Copper (II) nitrate solution to obtain copper metal at the end. Changes of copper complexes when various are added and filtering out the precipitate by using Buchner funnel for vacuum filtration. The experiment started with preparation of copper (II) hydroxide and addition of copper oxide then addition of droplets of chloride complex. Then the addition of ammonium complex and the preparation of copper metal. And the vacuum filtration takes place. Introduction Copper is a reddish-orange metal that is used widely in the electronics industry due to its properties of high ductility and conductivity. Results Reagents| Appearance| Volume (or Mass)| Concentration (or Molar Mass)| Cu(NO3)2 (aq)| Light blue solution| 10 ml| 0. 10 M| NaOH (aq)| Clear solution| 20 ml | 2 M| HCl (aq)| Clear solution| 20 drops| 6 M | NH3 (aq)| Clear solution| 7 drops| 6 M| H2SO4 (aq)| Clear solution| 15 ml | 1. M| Zn dust| Silvery substance| 0. 15 g| | ethanol| Clear solution| 5 ml | | Volume of Cu (NO3)2 (aq): 10 ml Concentration of Cu (NO3)2 (aq): 0. 10 M Convert ml to l: 10 / 1000 = 0. 010 liters Using the formulae: concentration = moles / volume 0. 10=moles/0. 010 Moles of Cu (NO3)2 (aq) = 0. 001 moles Mass of empty bottle = 6. 00grams Mass of empty bottle +copper metal =6. 05grams Mass of copper metal recovered after the experiment = 0. 050 grams Finding moles of copper: Moles = mass/ Mr = 0. 050 / 63. 55 =0. 00079 moles Volume of Cu (NO3)2 (aq): 10 ml We will write a custom essay sample on Lab Report specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer Concentration of Cu (NO3)2 (aq) : 0. 10 M Convert ml to l: 10 / 1000 = 0. 010 liters Using the formulae: concentration = moles / volume 0. 10=moles/0. 010 Moles of Cu (NO3)2 (aq) = 0. 001 moles Mass of empty bottle = 42. 53grams Mass of empty bottle +copper metal =42. 58grams Mass of copper metal recovered after the experiment = 0. 050 grams Finding moles of copper: Moles = mass/ Mr = 0. 05/ 63. 55 =0. 0008 moles Since we have got moles of copper metal and copper nitrate solution we can find the percentage yield of the copper metal obtained from the experiment. yield = actual value / theoretical value * 100% =moles of copper metal obtained/ moles of Cu (NO3)2 (aq) = 0. 0008/0. 001 * 100% =80% Thus the percentage yield of the copper obtained was 80 %. Addition of NaoH solution to Cu (NO3)2 gave a dark blue solution. After boiling the Solution gotten above, I sieved out the water and had CuO(s) left in the Beaker. The addition of HCl (drop wise) to CuO gave a yellowish green solution. When NH4OH solution was added it gave a yellowish green solution. I added 15ml of 1. m H2SO4 to yellowish green solution co I suspect the copper complex to be [Cu (H2O) 6]2+, since it gave a blue-green solution. When zinc dust was added to The solution a shiny reddish brown metal was formed. Discussion It is observed that copper was conserved throughout the experiment. And despite The conservation of copper in the reaction, the percentage recovery of copper is less than 100%. i had 80% of copper recovered from Cu (NO3)2. After pouring out the supernatant some CuO clung to the wall of the beaker. Therefore, the HCl did not dissolve all of the CuO. This unreacted CuO causes a decrease in the mass of Cu recovered. Also, I forgot to scrunch the copper formed before drying. The clumps of copper might contain some water which increases its mass when weighed. It is necessary to synthesize the various compounds one after the other in order to recover copper metal because, it is not possible to get copper metal because it is not possible to get copper directly from Cu (NO3)2. all these phases are needed to be passed through. When zinc is added a zinc hexaquo complex is formed from the bonding of Zn2+ with six molecules of water. The addition of H2SO4 causes the Cu2+ from Cu(OH)2 to combine with water molecules to form [Cu(H2O)6]2+. The Cu(OH)2 is gotten from reaction of CuCl2 with NH3. The percent yield depends on whether certain reactions were completed or not. my percent yield 80% is affected by incomplete reaction of CuO with HCl. During the decomposition of Cu (OH) 2, some Cu might have been lost in heat form. Also when transferring the copper from the Buchner funnels into the weighing bottle, some copper metal were stuck to the funnel. This would also decrease the percent yield of copper gotten. Conclusion Given the concentration of Cu (NO3)2 and volume as 10. 0ml, the percent recovery of copper gotten from synthesis of copper compounds is 80%. References Cotton Albert; Wilkinson ,Geoffrey ;murillo,carlos;bochmann,Manfred. advanced inorganic chemistry,6th Ed; John Wiley and sons ltd:Canada,pp868-869 Lab Report Essay Example Lab Report Essay Determining the Acceleration Due to Gravity with a Simple Pendulum Quintin T. Nethercott and M. Evelynn Walton Department of Physics, University of Utah, Salt Lake City, 84112, UT, USA (Dated: March 6, 2013) Using a simple pendulum the acceleration due to gravity in Salt Lake City, Utah, USA was found to be (9. 8 +/- . 1) m/s2 . The model was constructed with the square of the period of oscillations in the small angle approximation being proportional to the length of the pendulum. The model was supported by the data using a linear ? t with chi-squared value: 0. 7429 and an r-square value: 0. 99988. This experimental value for gravity agrees well with and is within one standard deviation of the accepted value for this location. I. INTRODUCTION The study of the motion of the simple pendulum provided valuable insights into the gravitational force acting on the students at the University of Utah. The experiment was of value since the gravitational force is one all people continuously exp erience and the collection and analysis of data proved to be a rewarding learning experience in error analysis. Furthermore, this experiment tested a mathematical model for the value of gravity that that makes use of the small-angle approximation and the proportional relationship between the square of the period of oscillations to the length of the pendulum. Sources of error for this procedure included precision in both length and time measurement tools, reaction time of the stopwatch holder, and the accuracy of the stopwatch with respect to the lab atomic clock. The ? nal result of g takes into account the correction for the error introduced using the approximation. There are opportunities to correct for the e? cts of mass distribution, air buoyancy and damping, and string stretching[1]. Our results do not take these e? ects into account at this time. A. Theoretical Introduction The general form of Newton’s Law of Universal Gravitation can be used to ? nd the force between any two bodies. FG = ? G mME ? 2 r RE (1) 2 On earth this equation can be simpli? ed to F = ? mg? with the value r GME 2 RE taken to be the constant g. The value of gravity in Salt Lake City (elev. 1320 m) according to this model is: 9. 81792 m/s2 [3][4][5]. The simple pendulum provides a way to repeatedly measure the value of g. We will write a custom essay sample on Lab Report specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer The equation of motion from the free body diagram in Figure 1[2]: FIG. 1: Free body diagram of simple pendulum motion[2]. F = ma = mgsin? can be written in di? erential form ? g ?=0 L The solution to this di? erential equation relies on the small angle approximation sin? ?: (2) (3) ? for small ?(t) = ? 0 cos( g ) L (4) 3 The Taylor expansion ?(t) ?o [1 ? gt2 g 2 t2 ] + 2L 4! L2 (5) allows us to take the ? dependence out of the equation of motion. Taking the second derivative of the approximation gives the following: g ? ? = 0 L (6) 0 g g g g + ? = 0 =? ?0 = ? L L L L g L, (7) 4? 2 T2 ? We know from the ? rst derivative ? = ? so it follows that since ? 2 = = g L ?0 . g 4? 2 =? 2 L T (8) From the initial conditions it is also clear that the initial amplitude ? is equal to ? 0 and so the linear relationship between length L and period T 2 can be expressed as T2 = . 4? 2 L g (9) Using the small angle approximation introduces a small systematic error in the period of oscillation, T. Fo r instance the maximum amplitude angle ? for a 1 percent error is . 398 radians or 22. 8 degrees; to reduce the error to 0. 1 percent the angle must be reduced to . 126 radians or 7. 2 degrees. This experiment used an angle of about 10 degrees and that introduced an error of 0. percent. The calculations for the systematic error are found in the Appendix. II. EXPERIMENTAL PROCEDURE A. Setup As seen in Figure 2, the pendulum apparatus was set up using a round metal bob with a hook attached to a string. The string passed through a hole in an aluminum bar, which was attached to 4 the wall. The length of the string could be adjusted, and the precise point of oscillation was ? xed by a screw, which also connected a protractor to the aluminum bar. FIG. 2: Experiment setup. Length measurements for the pendulum were taken using a meter stick and caliper. The caliper was used to measure the diameter of the bob, having an uncertainty of 0. 01cm. The total length was measured by holding the meter stick up against the aluminum bar, and measuring from the pivot point to the bottom of the bob. The bottom was determined by holding a ruler horizontally against the bottom of the bob. The meter stick measurements had an uncertainty of 0. 2cm. Time measurements were made using a stopwatch. For measuring the ? rst swing the starting time was determined by holding the bob in one hand and the stopwatch in the other and simultaneously releasing the bob and pushing Start. The stopping point, and starting point for the second oscillation, was determined by watching the bob and pushing Stop/Start when the bob appeared to reach the top of the swing and stop. The precision of the stopwatch was compared with an atomic clock by measuring several one second intervals. The precision of the time measurements were also a? ected by reaction time and perception of starting and stopping points of the person taking the measurements. Time measurements were taken by the same person to keep the uncertainty in reaction time consistent. 5 B. Procedure To determine which measurements weremost reliable, data was taken for the period of the ? rst oscillation, second oscillation, and twenty oscillations (omitting the ? rst) at a set length of 20. 098 cm. The length was then adjusted to 65. 5647 cm, and the same measurements were taken. To see the limits of the small angle approximation measurements of 20 oscillations (omitting the ? rst) at a ? xed length of 60. 1605 cm were taken by beginning the swing at angles of 5, 10, 20, and 40 degrees. Measurements were then taken for 20 oscillations (omitting the ? rst) for lengths of 20. 098, 26. 898, 32. 898, 60. 1605, 65. 6467, 74. 648, 89. 848, 104. 548, 116. 498, and 129. 898 cm at a starting angle of about 10 degrees. III. RESULTS The result for g obtained from both measured values of L and T 2 from equation 9 as well as from the slope in the Linear Fit model (Figure 4) agree very well with accepted results for g. The precision could be improved by corrections for e? ects of mass distrib ution, air buoyancy and damping, and string stretching[1]. TABLE I: Period measurements at di? erent Angles Degrees 3 5 10 20 40 Average Period of 20 Oscillations 31. 18333 31. 24833 31. 266 31. 50833 32. 06667 Average Period of Oscillation 1. 559167 1. 62417 1. 5633 1. 575417 1. 60333 IV. DISCUSSION By measuring 20 oscillations the average period is determined by dividing by 20 and this helps reduce the error since the error propagation will provide an uncertainty in the period that is the uncertainty in the time measurement divided bytwenty. From Table 1 and Figure 3 the limits of the small angle approximation are shown. Between 10 and 20 degrees the theoretical model begins to breakdown and the measured period deviates from the theoretical value. Measurements taken at less than 10 degrees will be more accurate for the small angle approximation model that was used. Two methods were used to calculate a value of g from the data. The ? rst method used to calculate a value of g from the measurements taken is making the calculation from each of the 6 1. 62 1. 60 T (sec) 1. 58 1. 56 1. 54 0 5 10 15 20 25 30 35 40 45 Angle (degrees) FIG. 3: Period dependence on angle as ? increases from 3-40 degrees. Equation W eight Residual Sum of Squares y = a + b*x Instrumental 0. 77429 Value Intercept T^2 Slope 0. 01559 4. 01435 Standard Error 0. 03001 0. 04913 T 2 (sec ) 2 Length (m) FIG. 4: Linear Fit graph with error bars in T 2 . The slope of this line was used to calculate g. en di? erent lengths, using the measurements shown inTable 7 of 20 oscillations at the di? erent lengths, and taking the average. The calculated average g was (9. 7 + / ? 0. 1) m/s2 . The second method used was applying a linear least squares ? t to the values of length and the 7 accompanying T 2 . Figure 4 shows this method and gives the values for the ? t parameters. The value of g is determined by using the slope of the line and gave a value of g to be (9. 8 + / ? 0. 1) m/s2 . Figure 5 shows that data has a random pattern and all of the error bars go through zero, which means that the data is a good ? for a linear model. 0. 10 0. 05 Residual T 2 0. 00 -0. 05 -0. 10 0. 2 0. 4 0. 6 0. 8 1. 0 1. 2 1. 4 Independent Variable FIG. 5: Random pattern of Residual T 2 . As discussed in the theoretical introduction, a value of g 9. 81792 m/s2 can be calculated using G, ME , and RE . The value of g varies depending on location due to several factors including the non-sphericity of the earth, and varying density. A more accurate value of g in Salt Lake City, Utah can be calculated by taking into account these e? ects. The National Geodetic Survey website, which interpolates the value of g at a speci? latitude, longitude and elevation from observed gravity data in the National Geodetic Survey’s Integrated Data Base, was used to determine an accepted value of g for Sal t Lake City, Utah, for which to compare the calculated results[7][8][6]. The accepted value for g in Salt Lake City, Utah is (9. 79787 + / ? 0. 00002) m/s2 . Comparing the two methods used to calculate g shows that the least squares linear ? t provided a value of g that is closer to the theoretical[3][4][5] and accepted[7][8][6] values of g. The calculation of g supports the small angle approximation model that was used. The linear relationship to length and period squared provided by the approximation gave a way of employing a least squares linear ? t to the data to determine a value of g. Since the calculated value was 8 within one standard deviation from the theoretical value, the model was supported. V. CONCLUSION The small angle approximation model, which gives g as being proportional to T 2 and L, was supported by the data taken using a simple pendulum. The residual of the data showed that it was a good ? t for a linear model, and the least squares linear ? t of the data had ? t parameters of chi-squared: 0. 7429 and an r-square value: 0. 99988. The value of g taken from the slope of the least squares linear ? t provided a value of g: (9. 8 + / ? 0. 1) m/s2 , which is within one standard deviation of the accepted value of gravity in Salt Lake City: 9. 79787 m/s2 [6]. The experiment was a good way of testing the small angle approximation because the period measured using di? erent starting angle s was consistent for angles less than 10 degrees. Using the small angle approximation the relationship between period squared and length was linear so a least squares linear ? t could be utilized to calculate g. The value of g calulated using the least squares linear ? t could then be compared to the accepted value of g for the location, thus verifying the model that was employed. [1] R. A. Nelson, M. G. Olsson, Am. J. Phys. 54, 112 (1986). [2] A. G. Dall’As? n, Undergraduate Lab Lectures, University of Utah,(2013). e [3] B. N. Taylor,The NIST Reference,physics. nist. gov/cuu/Reference/Value? bg,(2013). [4] D. R. Williams, Earth Fact Sheet, nssdc. gsfc. nasa. gov/planetary/factsheet/earthfact. html, (2013). [5] Salt Lake Tourism Center, http://www. slctravel. com/welcom. htm, (2013). [6] National Geodetic Survey,www. gs. noaa. gov/cgi-bin/grav-pdx. prl, (2013). [7] Moose, R. E. , The National Geodetic Survey Gravity Network, U. S. Dept. of Commerce, NOAA Technical Report NOS 121 NGS 39, 1986. [8] Morelli, C. : The International Gravity Standardization Net 1971, Internation al Association of Geodesy, Special Publication 4, 1971. 9 VI. A. APPENDIX A Error Analysis B. Time The sources of error introduced in this experiment came from the tools we used to measure length: calipers for the bob and a meter stick for the string length as well as the stop watch used to time each period of oscillation. Measuring the period had several sources of error including precision, the atomic clock benchmark, the reaction time of the experimentor, and the statistical error which was the standard deviation from the measurements taken. On the whole, the relative error in T was greater so that was the error used in the linear ? t analysis. ?T = 1 20 (? Treaction )2 + (? Tatomic )2 + (? Tprecision )2 + (? Tstatistical )2 (10) Equation 10 also takes into account the error propagation in taking the time period for twenty oscillations. This ? T is the random error; to account for the systematic error introduced by using the small angle approximation the complete solution for the period of oscillation is as follows [2]: 1 ? max 9 ? max T (? max ) = T0 + T0 [ sin2 ( ) + sin4 ( )] 4 2 64 2 (11) To ? nd the percent error introduced by the angle used in the experiment the solution in equation 11 was rearranged to give: T (? max ) ? To 1 ? max 9 ? max = sin2 ( ) + sin4 ( ) T0 4 2 64 2 (12) The angle used in this experiment was 10 degrees. Plugging that value into the right side of equation twelve gives a value of . 002967. It follows that T0 = T (? max ) 1. 002967 (13) Each of our measured values of T was corrected by this factor. To get the error for T 2 : ? T 2 = T ? T The results are found in Table 7. These values were plotted in ? gures 4 and 5. (14) 10 C. Gravity The errors in the calculations for g were determined di? erently for the two methods. The uncertainty in the least square ? t was calculated from the slope and uncertainty of the slope (see Figure 4). ?g = The calculations of g from L and T 2 used: ? g = g ( These values are found in Table 8. 4? 2 ? m m2 (15) ?L 2 ? T 2 2 ) + (2 ) L T (16) Lab Report Essay Example Lab Report Paper If the room temperature for this experiment had been lower, the length of he resonating air column would have been shorter, The length of air column is directly proportional to temperature due to -?31 masts. 2. An atmosphere of helium would cause an organ pipe to have a higher pitch because the speed of sound is taster in helium, but since the pitch tot a tuning fork has a set frequency, the pitch will not change, 3. If you measure an interval of S seconds between seeing a lighting flash and hearing the thunder with the temperature of air being ICC, the lightning was 1715 meters away, x=mm 4. If a tuning fork is held over a resonance tube at ICC, and resonance occurs t 12 CM and 34 CM below the top of the tube, the frequency of the tuning fork is 783 Hzs- XX=LA-LA In-0. 340. 12 v-messmates v=331ms296273 v-345 ms 345 m) t-783 Hzs CONCLUSION The purpose of this experiment was to use tuning forks of known frequencies to create wavelengths by making sound waves and measuring the air column, This resonance tube apparatus will represent a closed pipe. Wavelengths may be found by measuring the difference between two successive tube lengths at which resonance occurs and will be half the wavelength. The original hypothesis for this experiment was that the speed of the sound will be greater due to the enrapture of the air being higher. In the experiment, when the water was lowered to different heights which in turn caused a change in length of the air columns. Which then allowed the tuning fork to resonant. We will write a custom essay sample on Lab Report specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer In the percent error calculation, the experimental value was 348 urn/s and the theoretical speed of sound avgas 343 m/s, which avgas a error. In the experiment, learned that as frequency increases, the wavelength decreases. The experiment verified the principle of resonance in a closed tube. The original hypothesis was proven during the experiment; the speed Of sound Of Will be greater due to the temperature of the air being higher. Lab Report Essay Example Lab Report Paper The arm may be a bent portion of the shaft, or a separate arm attached to it. Attached to the end of the crank by a pivot is a rod, usually called a connecting rod. The end of the rod attached to the crank moves in a circular motion, while the other end is usually constrained to move in a linear sliding motion. In a reciprocating piston engine, the connecting rod connects the piston to the crank or crankshaft. Together with the crank, they form a simple mechanism that converts linear motion into rotating motion. Connecting rods may also convert rotating motion into linear motion. Historically, before the development of engines, they were first used in this way. In this laboratory we will investigate the kinematics of some simple mechanisms used to convert rotary motion into oscillating linear motion and vice-versa. The first of these is the slider-crank a mechanism widely used in engines to convert the linear thrust of the pistons into useful rotary motion. In this lab we will measure the acceleration of the piston of a lawn mower engine at various speeds. The results exemplify a simple relation between speed and acceleration or kinematical restricted motions, which will discover. An adjustable slider- crank apparatus and a computer simulation will show you some effects of changing the proportions of the slider-crank mechanism on piston velocity and acceleration. Other linkages and cam mechanisms may also be used for linear- rotary motion conversion and some of these will be included in the lab Abstract The distance between the piston and the centre of the crank is controlled by the triangle formed by the crank, the connecting rod and the line from the piston to the centre of the crank, as shown in [ Figure 1 1. We will write a custom essay sample on Lab Report specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer Since the lengths of the crank and connecting rod are constant, and the crank angle is known the triangle POP is completely defined. From this geometry, the distance s is given by [1]: The rightmost position of P occurs when the crank and connecting rod are in line along the axis at P and the distance from O to P is I + r. Since the distance measured in the experiment uses this position as the reference location, the distance measured is given by: This means that x is a function of the crank angle O and that the relationship is not linear. Figure 1 Geometry of Crank and Connecting Rod Mechanism Procedure 1 . )III of equipments for experiment of slider crank are set in good condition. 2. )Before taking readings,we turned the crank slowly and watched the movement of the piston to make sure it moves in the correct direction 3. ) The angle of the circle, is twisted at degrees and a resulting distance that the piston moves, q is measured. The position of sliding block/slider, x is calculated 4. ) The procedures number 3 and number 4 are repeated with an increasing angle of 5 degrees until the angle of circle reaches 3600 5. ) The graph of the position of slider, against angles of circle, is plotted. Apparatus Crank and connecting rod assembly Conclusion From the experiment we can conclude that the motion of the piston will gradually approach simple harmonic motion in increasing value of connecting rod and crank ratio. Even though that is the case in this experiment we did not really get the graph as said in theory but it is almost the same. I believe that we had done something wrong while doing the experiment. The graph plotted can be shown that almost all the graphs tend to move to simple harmonic motion. The experiment was a simple one but it really needs a lot of time to take the eating. Lab Report Essay Example Lab Report Paper Countersink: Used to stain red the cells that have been decolonize (Gram cells). C. Decontrolling agent: removes the primary stain so that the countersink can be absorbed. D. Mordant: Increases the cells affinity for a stain by binding to the primary stain. Source: Microbiology A Laboratory Manual 4th Edition/ James G. Cappuccino, Natalie Sherman/ 2008/ Pages 73 ; 74 Question 3: Why is it essential that the primary stain and the countersink be of contrasting colors? Answer: Cell types or their structures can be distinguished from one another on the basis of the stain that is retained. Source: Microbiology A Laboratory Manual 4th Edition/ James G. Cappuccino, Natalie Sherman/ 2008/ Pages 73 Question 4: which is the most crucial step in the performance of the Gram staining procedures? Explain. Answer: Decentralization is the most crucial step of the Gram stain. Over-decentralization will result in lost of the primary stain causing Gram positive organisms to appear Gram negative. Under-decentralization will not completely remove the C.V.-I (crystal-violet-iodine) complex, causing Gram negative organisms to appear Gram positive. Source: Microbiology A Pages 74 Question 5: Because of a snowstorm, your regular laboratory session was cancelled and the Gram staining procedure was performed on cultures incubated for a longer period of time. Examination of the stained Bacillus cereus slides revealed a great deal of color variability, ranging from an intense blue to shades of pink. Account for this result. Answer: The organisms lost their ability to retain the primary stain and appear to be gram-variable. Source: Microbiology A Laboratory Manual 4th Edition/ James G. We will write a custom essay sample on Lab Report specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer Cappuccino, Natalie Sherman/ 2008/ Pages 74 LAB EXPERIMENT NUMBER 12 The purpose of the Acid fast stain is to identify the members of the genus Mycobacterium, which represent bacteria that are pathogenic to humans. Mycobacterium has a thick, waxy wall that makes penetration by stains extremely difficult so the acid fast stain is used because once the primary stain sets it cannot be removed with acid alcohol. This stain is a diagnostic value in identifying these organisms. MATERIALS: * Bunsen burner * Hot plate * Inoculating loop * Glass slides * Bibulous paper * Lens paper * Staining tray * Microscope METHODS: 1. Prepared a bacterial smear of M. Schematic, S. Erasures, ; a mixture of M. Schematic ; S. Erasures 2. Allowed 3 bacterial slides to air dry ; then heat fixed over Bunsen burner 8 times. . Set up for staining over the beaker on hot plate, flooded smears with primary stain-crystal fuchsia and steamed for 8 minutes. 4. Rinsed slides with water 5. Decolonize slides with acid alcohol until it runs clear with a slight red color. 6. Rinsed with water 7. Countersigned with methyl blue for 2 minutes 8. Rinsed slides with water. 9. Blot dry using bibulous paper and examine under oil immersion * Mycobacterium Schematic * S. Erasures * A mixture of S. Erasures ; M. Schematic RESULTS AND DATA USED: 1. M. Schematic, a bacilli bacteria that colored pink resulting in acid fast. 2. S. Urges, a Cisco bacteria that colored blue resulting in non acid fast. 3. M. Schematic ; S. Erasures resulted in both acid fast ; non acid fast. CONCLUSION The conclusion to the acid fast stain is that S. Erasures lacks a cellular wax wall causing the primary stain to be easily removed during decentralization, causing it to pick up the countersink-methyl blue. This results in a non acid fast reaction, meaning it is not in the genus Mycobacterium. M. Schematic has a cellular wax wall causing the primary stain to set in and not be decolonize; this results in an acid fast reaction meaning it is in the genus Mycobacterium. REVIEW QUESTIONS Question 1: Why must heat or a surface-active agent be used with application of the primary stain during acid-fast staining? Answer: It reduces surface tension between the cell wall of the embarcadero and the stain. Source: Microbiology page 79 Question 2: Why is acid-alcohol rather than ethyl alcohol used as a decontrolling agent? Answer: Acid-fast cells will be resistant to decentralization since the primary stain is more soluble in the cellular waxes than in the decontrolling agent. Ethyl alcohol would make the acid fast cells non-resistant to the decentralization. Source: Microbiology A Laboratory Manual 4th Edition/ James G. Cappuccino, Natalie Sherman/ 2008/ page 79 Question 3: What is the specific diagnostic value of this staining procedure? Answer: Acid-fasting staining represents bacteria that is pathogenic to humans Question 4: Why is the application of heat or a surface-active agent not required during the application of the counter stain in acid-fast staining? Answer: The counter stain methyl blue is only needed to give the stain its color. Source: Microbiology A page 79 Question 5: A child presents symptoms suggestive of tuberculosis, namely a respiratory infection with a productive cough. Microscopic examination f the childs sputum reveals no acid-fast rods. However, examination of gastric washings reveals the presence of both acid-fast and non-acid fast bacilli. Do you think the child has active tuberculosis? Explain. Answer: Yes, the child may have active tuberculosis. Although, acid-fast microorganisms are not easily removed and non-acid fast are. Tuberculosis represents bacteria that are pathogenic to humans, the stain is of diagnostic value identifying these organisms. Source: Microbiology A Laboratory Manual 4th Edition/ James G. Cappuccino, Natalie Sherman/ 2008/page 79 LAB EXPERIMENT NUMBER 13 The purpose of this experiment is to identify the difference between the bacterial spore and vegetative cell forms. The vegetative cells are highly resistant, metabolically inactive cell types. The endoscope is released from the degenerating vegetative cell and becomes an independent cell. MATERIALS: * hot plate * staining tray * inoculating loop * glass slides * bibulous paper * lens paper * microscope 1 . The spore stain (Schaeffer-Fulton Method) is performed on a microscopic slide by making an individual smear of the bacteria on slide and heat fixing until dry. 2. Flood the smears with malachite green and place on top of a beaker of warm eater on a hot plate, allowing it to steam for 5 minutes. 3. Remove the slide and rinse with water. 4. Add counter stain seafaring for 1 minute then rinse again with water and blot dry with bibulous paper. MICROORGANISMS USED: * S. Erasures * S. Erasures B. Rues mix RESULTS/DATA USED 1. B. Cereus- green spores, pink vegetative cells, endoscope located in center of cell 2. B. Cereus S. Erasures- green spores, pink vegetative cells, endoscope located in center of cell CONCLUSION: An endoscope is a special type of dormant cell that requires heat to uptake the primary stain. To make endoscopes readily noticeable, a spore stain can be used. In using a microscope, under oil immersion, you will be able to identify the color of the spores, color of the vegetative cells and be able to locate the endoscope in certain bacteria like S. Erasures and B. Cereus. Question 1: Why is heat necessary in spore staining? Answer: The heat dries the dye into the vegetative cell of the spore. Source: Microbiology Lab Manual, 8th edition, Cappuccino Sherman, p. 85 Question 2: Explain the function of water in spore staining. Answer: The water removes the excess primary stain, while the spores remain green the water nines the vegetative cells that are now colorless. Source: Microbiology Lab Manual, 8th edition, Cappuccino Sherman, p. 85 Question 3: Assume that during the performance of this exercise you made several errors in your spore- staining procedure. In each of the following cases, indicate how your microscopic observations WOUld differ from those observed when the slides were prepared correctly. Answer: a. ) You used acid-alcohol as the decontrolling agent. The alcohol would wash out all coloring from the bacteria. Source: Microbiology Lab Manual, 8th edition, Cappuccino Sherman, p. 5 b. ) You used seafaring as the primary stain and malachite green as the countersink. Seafaring will absorb to vegetative cells and not endoscopes since you need heat for endoscopes to form and malachite green will not absorb without heat but it will to vegetative cells. Source: Microbiology Lab Manual, 8th edition, Cappuccino Sherman, p. 85 c. ) You did not apply heat during the application of the primary stain. Without heat, the endoscopes will not form and it will not penetrate the spore to color the vegetative cell. Microbiology Lab Manual, 8th edition, Cappuccino Sherman, p. 5 Question 4: Explain the medical significance of a capsule. Answer: The capsule protects bacteria against the normal phagocyte activities of the host cells. Source: Microbiology Lab Manual, 8th edition, Cappuccino Sherman, p. 7 Question 5: Explain the function of copper sulfate in this procedure. Answer: It is used as a decontrolling agent rather than water, washes the purple primary stain out of the capsular material without removing the stain bound to the cell wall, the capsule absorbs the copper sulfate and will appear blue. Cappuccino Sherman, p. 88 LAB EXPERIMENT NUMBER AAA The purpose of this experiment is to identify the best chemotherapeutic agents used for infe ctious diseases. S. Erasures is the infectious disease used for this experiment. MATERIALS: * Sense-disc dispensers or forceps * sterile cotton swabs * glassware marking pencil * millimeter ruler Using the Kirby-Bauer antibiotic sensitivity test method is used. This method Uses an Antibiotic Sense-disc dispenser, which placed six different types of antibiotics on an Mueller-Hint agar plate, infected with S. Erasures. The antibiotics are in the form of small, round disc, approximately mm in diameter. The antibiotics are placed evenly away from each other on the S. Erasures infected Mueller-Hint agar plate and incubated at 37 degrees Celsius for up to 48 hours. After the completed incubation time, any area surrounding the antibiotic disc which shows a clearing or an area of inhibition is then measured. Measurements are taken from the diameter of each antibiotic area of inhibition. This measurement will determine which of the antibiotics is best to be used against the specific organism. (In this case, S. Erasures) MICROORGANISMS USED: S. Erasures ANTIBIOTICS USED: Autocratic Erythrocyte Cylindrical Geocentric Fancying Linemen A chart showing the measurements of each antibiotic is used to determine its effectiveness. The three different types of ranges are: Resistant (Least useful) Intermediate (Medium useful) Susceptible (Most useful) The following results are: Zone Size Autocratic mm (Susceptible) Erythrocyte mm (Intermediate) Cylindrical mm (Intermediate) Geocentric mm (Susceptible) Fancying 13 mm (Susceptible) Linemen 21 mm (Susceptible) CONCLUSION: 4 of the 6 antibiotics above can be effectively used against inhibiting this organism (S. Erasures). This information would be passed on to the provider of the infected patient, so the patient can be given the antibiotic chosen by their provider and recover from this infection. LAB EXPERIMENT NUMBER BOB The purpose of this experiment is to evaluate the effectiveness of antiseptic agents against selected test organisms. MATERIALS: The materials used are five Traipses soy agar plates. 24-48 hours Triplicate soy broth cultures of E. Coli, B. Cereus, S. Erasures and M. Specialist. The microorganisms used were E. Coli, B. Cereus, S. Erasures and M. Specialist. The data collected in this experiment shows chlorine bleach having the broadest anger of microbial activity because it has the strongest ingredients. Tincture of iodine and hydrogen peroxide seems to have the narrowest range because the contents arent as strong. CONCLUSION: The Agar Plate-Sensitivity Method shows the effectiveness of antiseptic agents against selected test organisms. The antiseptic exhibited microbial activity against each microorganism. Question 1: Evaluate the effectiveness of a disinfectant with a phenol coefficient of 40. Answer: A disinfectant with a phenol coefficient of 40 indicates the chemical agent being more effective than the phenol. Source: Microbiology A Laboratory Manual 4th Edition/ James G.