Lab Report Free Essays

Lab #7 Purpose: The purpose of this experiment is to analyze known solutions of Ba(NO3)2, Ca(NO3)2, Mg(NO3)2 and Sr(NO3)2 (alkaline earths) and known solutions of NaBr, NaCl and NaI (halogens). Then we are given an unknown solution to determine what ions are present. Materials: 1. We will write a custom essay sample on Lab Report or any similar topic only for you Order Now Test tubes 2. Test tube holder 3. Pipet 4. 1 M H2SO4 5. 0. 1 M Na(NO3)2 6. 0. 1 M Ca(NO3)2 7. 1 M Na2CO3 8. 0. 25 M (NH4)2C2O4 9. 0. 1 M KIO3 10. Bromine water 11. Chlorine water 12. Iodine water 13. 0. 1 M NaCl 14. 0. 1 M NaBr 15. 0. 1 M NaI 16. Unknown (E) Methods: Alkaline Earths 1. Wash the test tubes of any residue 2. Add 12 drops of 1m H2SO4 to four test 3. Then add 12 drops of 0. 1m Ba(NO3)2 to one test tube containing 1M H2SO2 4. Add 12 drops of 0. 1m Ca(NO3)2 to another test tube containing 1M H2SO2 5. Add 12 drops of 0. 1m Mg(NO3)2 to another test tube containing 1M H2SO2 6. Add 12 drops of 0. 1m Sr(NO3)2 to the final test tube containing 1M H2SO2 7. Observe and take notes on the precipitate or the lack of precipitate in each reaction 8. Clean the test tubes after taking notes . Repeat the procedure, but now with 12 drops of 1m Na2CO3 in each test tube 10. Add 12 drops of 0. 1M Ca(NO3)2 to another test tube containing 1M Na2CO3 11. Add 12 drops of 0. 1M Mg(NO3)2 to another test tube containing 1M Na2CO3 12. Add 12 drops of 0. 1M Sr(NO3)2 to the final test tube containing 1M Na2CO3 13. Observe and take notes on the precipitate or the lack of precipitate in each reaction 14. Clean the test tubes after taking the notes 15. Repeat the proce ss with 12 drops of 0. 25M (NH4)2C2O4 16. Observe and take notes on the precipitate or the lack of precipitate in each reaction 17. Clean the test tubes after taking the notes 18. Repeat the process with 12 drops of 0. 1M KIO3 19. Observe and take notes on the precipitate or the lack of precipitate in each reaction 20. Clean the test tubes after taking the notes 21. Repeat the process with 12 drops of unknown (E) 22. Observe and take notes on the precipitate or the lack of precipitate in each reaction and deduct if it’s Ba(NO3)2, Ca(NO3)2, Mg(NO3)2 or Sr(NO3)2. 23. Clean the test tubes after taking the notes Halogens 1. Place a few drops of bromine water into the test tube and add 12 drops of heptane and shake 2. Repeat the process with chlorine water and iodine water and note any color changes in each 3. Clean the test tubes after taking the notes 4. Get three test tubes and add 12 drops of bromine water to each test tube with 12 drops of HEP 5. Add 12 drops of 0. 1M NaCl to the first test tube, 12 drops of 0. 1M NaBr to the second test tube and 12 drops of 0. 1M NaI to the third test tube 6. Note the color of each reaction 7. Clean the test tubes after taking the notes . Repeat the steps but with 12 drops of chlorine water in each test tube with 12 drops of HEP 9. Observe the color of each reaction 10. Clean the test tubes after taking the notes 11. Repeat the steps but with 12 drops of iodine water in each test tube with 12 drops of HEP 12. Observe the color of each reaction 13. Clean the test tubes after taking the notes 14. Repeat the steps but with 12 drops of unknown (E) in each t est tube with 12 drops of HEP 15. Observe the color of each reaction and deduct if the unknown is either NaBr, NaCl or NaI Results: Alkaline | H2SO4| Na2CO3| (NH4)2C2O4| KIO3| Ba(NO3)2| Cloudy white| Very cloudy white| White precipitate sits on bottom| Tiny amounts of white precipitate| Ca(NO3)2| No reaction | Cloudy white| Cloudy white precipitate| No reaction| Mg(NO3)2| No reaction| White film on top| No reaction | No reaction| Sr(NO3)2| White precipitate on top| White cloudy solution with some white precipitate| Faint white cloudy foggy precipitate| Little amounts of tiny white precipitate| Unknown (E) | No reaction | White film on top| No reaction| No reaction| . Unknown Alkaline Earth: Mg(NO3)2 Reaction between Halogens and Halides | NaBr| NaCl| NaI| Unknown (E)| Bromine water| Light faint yellow| Golden yellow| Faint yellow tint| Light faint yellow| Chlorine water| Dark yellow amber | Colorless| Light yellow| Dark yellow amber| Iodine water| Light yellow tint| Dark red color| Light yellow| Light yellow tint| Unknown Halogen: NaBr Color of Halogens in solution | Br2| Cl2| I2| Water| Orangey-Brown| Colorless| Brown| HEP| Orange| Colorless| Purple | Conclusion: How to cite Lab Report, Papers Lab Report Free Essays In order to determine the relationship between coffee consumption and two types of vital signs, respiration rate and blood pressure, my group (Group 4) designed a lab that measured the respiration rate and blood pressure of two participants, once after consuming water and then again after consuming coffee. After testing two participants blood pressure and respiration rate, it was found that the vital signs of the participants remained the same after consuming water but decreased slightly after consuming coffee. This lab is significant because it demonstrates that the consumption of coffee, on the contrary to Group 4’s hypothesis, caused a decrease in the vital sign measurements of the two participants rather than increasing as we initially hypothesized. We will write a custom essay sample on Lab Report or any similar topic only for you Order Now This lab was done to determine and compare the effects that coffee drinking has on blood pressure and the respiration rate in two participants. The hypothesis configured by our group was that after drinking 1 cup of water the participant’s blood pressure and respiration rate would remain constant, but after the drinking 1cup of coffee the participants blood pressure and respiration rate would increase as a result of the common compounds found in coffee. The control in this experiment is 1 cup of water, because the participant’s blood pressure and respiration rate are being measured, but they have not been exposed to the common compounds found in coffee. The dependent variable in the study is the participant’s blood pressure and respiration rate because the vital signs are the component in the experiment that are being measured. The independent variable is what is changed in the experiment and in this experiment that would be the amount of the common compounds the participants consume in 1 cup of coffee. The results of our lab disproved our hypothesis, that consuming coffee would increase the participant’s blood pressure and respiration rate, as seen in Table 1, Graph 1, and Graph 2. Although our expectations of the measurement of vital signs after consuming 1 cup of water were correct, we had expected the results from the measurement of both the respiration rate and the blood pressure to noticeably increase after consuming coffee due to the common compounds found in coffee. The lab, actually, resulted in the decrease of respiration rate and blood pressure after the consumption of coffee. The study preformed by the National Cancer Institute measured the association between coffee and its affects on health, as a result of reading this article I conducted a study that worked off the same principle. However, in the lab I attempted to narrow the causal relationship between the two by measuring the participant’s vital signs, respiration rate and blood pressure, in relationship to consuming coffee versus water and any potential periods or repeated periods of evaluated or descended vital signs has to the longevity of one’s life. The results of the lab support the findings of the National Cancer Institute because the article states that consuming coffee has positive affects on health and our lab concluded that coffee consumption lowers blood pressure, which is necessary for a person that may struggle with high blood pressure to become healthy. During the lab, the participants physiology, blood pressure and respiration rate, was lowered after consuming coffee, this served to calm the participant’s vital signs. To improve the validity of the study a few changes could be made to improve the results. For example, I believe that the vital signs were not effected greatly because of the time span used to complete the study, after drinking the coffee we immediately took the vital signs instead of waiting for the full effect to take place. An additional reason for the higher levels of the vital signs before the consumption of coffee could have been due to activities done prior to the lab thus increasing the vital sings measured after drinking water. To improve upon these imperfections, the study could be done earlier in the day and with more resting periods before vital signs are taken. This lab was designed to determine the relationship between coffee consumption and two types of vital signs, respiration and blood pressure. The lab measured the respiration rate and blood pressure of two participants, once after consuming water and then again after consuming coffee. I hypothesized that the consumption of coffee would dramatically increase the participant’s respiration rate and blood pressure due to the consumption of the common compounds found in coffee that typically raise energy levels and alertness. However, the lab resulted in slightly lower respiration rates and blood pressure after the consumption of coffee than water as seen in Table 1, Graph 1, and Graph 2. The lab is significant because it demonstrates that the consumption of coffee, in contrast to our hypothesis, caused a decrease in the vital sign measurements of the two participants rather than increasing as we originally hypothesized. Works Cited National Institues of Health. â€Å"Coffee drinkers have lower risk of death, study suggests. † ScienceDaily, 19 May 2012. Web. 9 Oct. 2012 How to cite Lab Report, Essay examples Lab Report Free Essays Lab Report 3 In this lab, we will take a trip to the planetarium lab and will learn about Right ascension and declination, and altitude and zenith. After looking at the different points shown, we will log the altitude and zenith in the chart in our lab manual. Now we will look at the same points and label the right ascension and declination. We will write a custom essay sample on Lab Report or any similar topic only for you Order Now Then we will learn about the easiest way to locate the star Polaris. As we started the first program, we answered a few questions to make sure we knew the general idea of stars. Then we labeled the altitude and azimuth of five objects. Aldebran had a altitude of 54o and an azimuth of 203o. Betelgeuse had an altitude of 47o and an azimuth of 203o. Castor had an altitude of 62o and an azimuth 118o. Deneb had an altitude of 13o and an azimuth of 328o. Elnath had an altitude of 68o and an azimuth of 184o. After that, we looked at the right ascension and declination (RA and DEC). Aldebran had a RA of 4. 6 hours and a DEC of 16o. Elnath had an RA of 5. 3 hours and a DEC of 28o. Betelgeuse had an RA of 5. hours and a DEC of 8o. Castor had an RA of 7. 6 hours and a DEC of 32o. Deneb had an RA of 20. 7 hours and a DEC of 46o. Finally we looked at the Big Dipper and the Cassopia to find the star Polaris. This lab was super cool, I loved it. The planetarium was great way to learn more about the different constellations and stars in the sky. I never knew that Polaris was so close to the Big Dipper. Finding the all the right ascensions and declinations of the objects wer e fairly easy and felt like I learned to do it pretty easily now. How to cite Lab Report, Papers Lab report Free Essays string(169) " Use the stopwatch to measure the time it takes from the first drop of water entering the beaker to the instant the water begins to overflow from the top of the beaker\." Repeatability measurements were taken on a bolt to get the total length, and also measuring the low rate of a faucet by measuring the amount of time it took to fill a beaker. To ensure a more accurate sample, twenty measurements of each section were obtained. For the batch measurement portion of this lab, a multi-meter was used to measure the resistance in a pack of ten resistors. We will write a custom essay sample on Lab report or any similar topic only for you Order Now Each member measured the resistors twice to allow for more precise statistical analysis. After all measurements were recorded, statistical analysis such as mean, standard deviation, and true mean range with 90%, 95%, and 99% confidence intervals were used to obtain the results. Once calculations were made, it was determined that there was error in this vibratory due to the environment and to human error, however all of the results fell within the ranges of confidence for each given section. Relevance In this experiment length, flow rate, and resistance was measured and the true mean was calculated. It was observed that the true mean varied depending on the variation of the sample mean and sample standard deviation. It was shown that the population mean, or true mean, could not be found exactly, but could be estimated as a range with a certain level of confidence with the measurement of the sample mean and sample standard deviation. The knowledge practiced in this lab can be lawful in future experiments if say a company needs to estimate the population average with a specified level of confidence of a bolt that they only have a few samples of. Introduction There are multiple ways of measurement, as well as, many different types of ways to analyze raw data. In this lab the objective is to experiment with two different types of measurements, repeatability and batch measurements. Theoretically the bolt length plus the cap thickness (B+C) should be equal to the measured total length of the bolt(A). Taking multiple measurements done by multiple people until twenty samples re obtained measuring all four components of the bolt and obtaining the raw data of bolt measurements. By having multiple people take measurements a small amount of human error is removed in case one person didn’t measure as accurate. By having multiple measurements done by each person a bigger sample size is obtained, and bigger sample size typically means more accurate results. After the measurements were made a sample mean was calculated, as well as, a sample standard deviation for all four components of the bolt. The sample mean and sample standard deviation were 2 lactated to estimate the true mean of the population with a level of confidence of 90 and 95 percent. Once the true mean of each component was estimated a comparison was made between the total length(A) and the sum of the cap thickness(S) and bolt length(C). In theory (B+C) should equal the total length of the bolt(A), as they represent the same length. Though they should be the same, they are not. The sum of measurements, (B) and (C) yield a much wider range of true mean than the measurement of (A). This difference is created by multiple types of error such as, human error, maybe reading the caliper wrong. Or error such as mechanical error, maybe the caliper itself was broken or not calibrated. In the second module of this lab the flow rate of the faucet water is measured using a stop watch and a mall beaker. Obtaining the flow rate of the water in 20 different samples, then summarizing the raw data into sample mean and sample standard deviation. With the sample mean and standard deviation, the true mean is to be estimated with a confidence level of 90 percent and then again with 95 percent. In the third module the measurements were made in batches. The measurements of batches of resistors were measured with a Center Multi-meter to make sure they all locked in at the same resistance. The resistors measured in this lab were quite strong, getting up to kick. Each group member measured the batch of resistors twice, then a pooled mean and pooled standard deviation was calculated. Pooling all the members samples together gives us one large sample and a more accurate estimate of the true mean. Using these calculated pooled mean and standard deviation the true mean was found as a range with a 99 percent level of confidence, and then again with a 95 percent level of confidence. The experimental setup and procedures are described in section The results of the experiments can be found n section {V} followed by conclusions in section {VI}. The appendix with the data chart can be found in section{Veil} Testing the repeatability of the measurements and taking the sample average and sample standard deviation to compare with each other, as well as, estimate the population mean and standard deviation. In three different modules linear dimension, flow rate, and resistance were measured. The primary objectives of this lab are to practice using devices that measure length and flow rate, to apply statistical principles to raw data sets, and to become familiar with use off multi-meter. Formulas Used: Sample Mean Standard Deviation True Mean Range 3 Experiment: Equipment: Pittsburgh 6†³ Caliper Bolt Cent-Tech Digital Multi-meter CTD 10 pack of electrical resistors (gold, yellow, red, yellow) mall Beaker Digital Stopwatch Procedure: This experiment utilizes the billeted above. The experiment is broken down into three sections. First take the caliper and the bolt, calibrate the caliper to make sure that accurate measurements are collected. Measure the complete length of the bolt, thickness of the head, width of the threads and the length of the bolt to the base of the head. Repeat the measurement a total of twenty times split evenly between the roof members and record the results. Second, take a mall beaker and a stopwatch to the sink and turn the water faucet on to attain a constant flow rate of water. Use the stopwatch to measure the time it takes from the first drop of water entering the beaker to the instant the water begins to overflow from the top of the beaker. You read "Lab report" in category "Papers" Empty the beaker of water repeat this measurement a total of twenty times split evenly between the group members and record the results. For the last portion of this lab, take a pack of resistors and the multi-meter. Set the millimeter to the appropriate reference resistance and begin measuring each of the sisters one at a 4 time. Each member will measure the set of resistors twice for a total of twenty resistance measurements per each member of the group. Record the measurements from each member and calculate the true mean resistance. Procedure Changes: The only change/ improvement made to the experiment was during the batch measurement section. It was found that more accurate readings of each resistor could be attained by taping the resistor pack to the table to keep it in place while using the probes to measure the resistance. This change will allow the group to move quicker through the experiment and not to make any mistakes such as possibly measuring the same resistor twice in a row. The experimental procedure is very straight forward and the group should not encounter any difficulties. Results/Discussion This lab required three different modules to be completed with two different types of measurements: batch and repeatability. The bolt measurement along with the volume flow rate were to be completed using repeatability, while the resistance module used batch measurements. The data was to be recorded and put into tables and analyzed using the mean, standard deviation, and true mean to determine whether the measurements were in the desired confidence intervals. 5 Linear Dimension Module: The first set of data was recorded using a manual caliper and a bolt. Four measurements were to be taken from the bolt: length, cap thickness, bolt length, and major diameter. These measurements lead to some error as expected, mostly human error and calibration of the manual calipers. There was also some error due to the uneven sides of the bolt and the angle at which the calipers were held against the bolt. Table la. Shows the summarized data falls within the 95% Confidence Interval. Measurement Total Length (A) Cap Thickness (B) Bolt Length (C) Major Diameter (D) B+C Sample Mean (in. ) (in. ) 2. 2661 0. 0033 0. 2825 0. 0031 1 . 9791 0. 0262 . 30327 0. 0007 2. 2616 0. 0268 Table la. Statistics of Bolt Measurements (95%) [2. 265, 2. 267] [0. 2810, 0. 2839] [1. 967, 1. 991] [0. 3024, 0. 3030] [2. 249, 2. 274] The second part of the linear module was to compare the difference between the total length (A) and the sum of cap thickness and bolt length (B+C). The results show that there was a lower CLC with the total length measurement than with the addition of two parts. This is most likely because of the accuracy of two measurements has more mom for error from the angle of the calipers and human error. Table b. Shows the comparison of the two measurements. The full experimental data for the linear module is listed in Table A in the Appendix. Table b. Comparison of bolt statistics Flow Rate Module: Measurement of the flow rate from a sink using a stopwatch and beaker was the second of the repeatability measurements. This module produced the most error most likely from human error with stopping and starting of the stopwatch. The inconsistent flow from the sink also contributed to some of the error. The standard aviation in this experiment was high, but after 6 calculating the true mean range for a 90% and 95% confidence interval, the sample mean falls within both ranges with a few outliers. Table LLC. Shows the summary of the data. The full experimental data is listed in Table B in the Appendix . (ECMA/min) 5300. 95 CLC (ECMA/metro) 138. 835 [5247. 27, 5354. 3] Table LLC. Flow Rate Module Statistics 95% CLC (ECMA/metro) [5235. 97, 5365. 93] Resistance Module: In the final part of this lab, resistors were to be measured in batches from each of the group members. This section of the lab showed the most precision with the least error. From the color coded bands on the ten resistors, it was concluded that the value of the resistors was 470 sq. All of the results in table old. Show that the resistors were only reading 400 sq. All 60 recorded measurements were close to 400 ink which could be from mislabel resistors. The pooled mean of the three samples does fall within the 90% and 95% confidence intervals even with including some outliers in the data. The full experimental data can be found in Table C in the Appendix. Sample Mean (Q) 400. 033 99% (Q) 1. 588 [399. 02, 401. 05] Table old. Resistance Module Statistics 95% CLC (sq) [399. 29, 400. 78] Conclusion: This laboratory focused on repeatability measurements, batch measurements, and statistical concepts/ principles to analyze the collected data. This was achieved through the use of a caliper, stopwatch, and a digital multi-meter for measurement purposes. Using these tools, the group is able to measure length, flow rate, and resistance. The statistical concepts used in this lab were sample mean, standard deviation, true mean, and the range and level of confidence. The results of the linear dimension module prove that there is always going to be a small amount of human error when using devices such as a manual caliper. That error is relatively larger when trying to sum two measurements as compared to measuring a total length . The measurement of the bolt as a whole has a narrower CIA and true mean range of [2. 265, 2. 267]. The 7 standard deviation for total length (A) [0. 0033 in. ] supports the theory that measuring the entire length at once is more accurate than summing the cap thickness (B) and bolt length (C) together, which is evident by analyzing the standard deviation of (B+C) [0. 0268 in. ]. The results of the flow rate module show that there is significantly far more human error when trying to measure the time it takes for water o fill a beaker. This can be attributed to response time of starting/stopping the stopwatch. The standard deviation [138. 835 /min] seems high, but calculations show that the sample mean [5300. 5 /min] falls within the true mean range for CLC [5247. 27, 5354. 63 /metro] and also for 95% CLC [5235. 97, 5365. 93 /min]. The results of the resistance module indicated a difference between the sample mean [400. 033 sq] of the batch measurements and the supposed value of the resistors [470 sq] according to the color coded bands. This was the most precise module with a standar d deviation of [1. 588 sq] and all the pooled means fall within he 95% CLC with a true mean range of [399. 29, 400. 78 sq], and the 99% CLC with a range of [399. 02, 401. 05 sq]. This laboratory experiment allowed the group to differentiate between repeatability measurements and batch measurements and apply the statistical theories learned in lecture to analyze the collected data. To minimize error percentage, calibrating the caliper before each measurement might be advantageous. Another advantage might be making markings on the bolt where each member of the group takes measurements instead of at random/different spots each time. How to cite Lab report, Papers