Lab 2 Measurements: Accuracy and Precision A. Data Tables (36 points) Place your completed data tables into your report here: Data Table 1 Measurement | Data | Length of aluminum plastic packet | 4.50cm | Height of aluminum plastic packet | 7.50 cm | Temperature of faucet water | 26.0 degrees Celsius | Temperature of ice water | 10.0 degrees Celsius | Volume of water in 10-mL graduated cylinder | 10.0ml | Volume of water in 50-mL graduated cylinder | 9.0ml | Data Table 2 Measurement | Data | Inside diameter of 50-mL graduated cylinder | 2.50 cm | Height of 50-mL graduated cylinder | 10.0 cm | Water temperature | 25.0 degrees Celsius | Initial volume of water in 50-mL graduated cylinder | 10.0 mL | Mass of water in the 50-mL graduated cylinder (remember, 1 g of water weights 1 mL since its density is 1 g/mL) | 10.0gm | Volume of water and aluminum shot in 50-mL graduated cylinder | 18.0ml | Mass of aluminum shot (given on outside of packet) | 20.0gm | B. Follow-Up Questions (Show all calculations) Part I (Each question is worth 10 points.) 1. Convert the length and height measurements for the packet that contains the aluminum shot from units of cm to units of mm using the unit-factor method.
Turn off light and place thermometer in substance for 1 minute in order to determine the ending temperature 10. Record results 11. Repeat steps 6-10 until all substances have been tested OBSERVATIONS: Substance Ice Freshwater Saltwater Soil Compressed Leaves Beginning Temperature in ˚C 0 20 21 19 18 Ending Temperature in ˚C 3 22.5 24 23 26 Temperature Difference in ˚C 3 2.5 3 4 8
Laboratory Techniques and Measurements – Lab Report Assistant Exercise 1: Length, Temperature, and Mass Data Table 1. Length Measurements Object Length (cm) Length (mm) Length (m) CD or DVD 11.7 116.8 0.1 Key 6.1 61.0 0.1 Spoon 14.5 144.8 0.1 Fork 17.0 170.2 0.2 Data Table 2. Temperature Measurements Water Temperature (°C) Temperature (°F) Temperature (K) Hot from tap 65.1 149.2 338.3 Boiling 97.5 207.5 370.7 Boiling for 5 minutes 100.0 212.0 373.2 Cold from tap 23.0 73.4 296.2 Ice water – 1 minute 7.8 46.0 281.0 Ice water – 5 minutes 4.0 39.2 277.2 Data Table 3. Mass Measurements Object Estimated Mass (g) Actual Mass (g) Actual mass (kg) Pen or pencil 7.5 10.7 0.01 3 Pennies 8.0 7.4 0.007 1 Quarter 3.0 5.6 0.006 2 Quarters, 3 Dimes 15.7 18.2 0.02 4 Dimes, 5 Pennies 20.9 21.5 0.02 3 Quarters, 1 Dime, 5 Pennies 29.4 31.7 0.03 Key 8.6 10.0 0.01 Key, 1 Quarter, 4 Pennies 25.0 25.7 0.03 Questions: A) Water boils at 100°C at sea level. If the water in this experiment did not boil at 100°C, what could be the reason?
Determination of Freezing Point and Verification of Freezing Point Depression for a Mixture by Linah Richer Partners: Maike Blakely CHM317 Preformed: Nov. 8th, 2013 Report: Nov. 19th, 2013 Abstract: The purpose of this experiment is to determine the freezing point of the solvent, biphenyl, and verify the freezing point depression equation ΔTf=-ikfnsolutemsolvent. The addition of solute will lower the vapor pressure of the solvent/solute mixture resulting in the lowering of the freezing point for the mixture solution. The experiment resulted in the experimental difference in the two trial freezing points to be 0.08 K leading to a calculated change in temperature freezing to be -1.92 E -5 K, and an overall decrease in temperature freezing of the solute/solvent solution compared to the pure solvent solution. Introduction: Experimentally it is understood that the addition of a nonvolatile solute to a solvent will lower the vapor pressure, raise the boiling point and lower the freezing point. In this experiment, the freezing point for the solvent biphenyl will be determined theoretically and experimentally, as well as the verification of the freezing point depression equation for a solvent/solute mixture.
W = Wa + 1.06 Wa/1000 Table. Density of water at various temperatures. Temperature (°C ) 26 27 28 29 30 31 32 33 34 Density of water ( g mL-1) 0.99681 0.99654 0.99626 0.99597 0.99567 0.99537 0.99503 0.99473 0.99440 How to use a pipette 1 Rinse a 25-mL pipette with two or three small volumes of distilled water, and then with a complete volume of distilled water. 2 Do not immerse the tip of the pipette too deep into the water. The tip should not be above the water level so as to avoid any mishap during the suction of the water into the pipette via the pipette filler or suction bulb.
August 23, 2009 Lab Partner-Joey Stabel The Analysis of Alum K.Schuyler Elvir Malikic Purpose Determining and understanding the characteristics of Aluminum Pre-Lab questions 1) When finding a melting point, why is it necessary to raise the temperature very slowly when approaching the melting temperature? When raising the temperature very slowly it gives the thermometer time to display the accurate temperature of the substance giving you a more accurate reading. Another reason would be the visual of things changing in a slower giving you time to examine what’s happening. 2) Washing soda is a hydrated compound whose
It can live and grown with or without oxygen. B. Discuss the temperature requirements of the organisms in this lab. The temperature requirement for this lab was 37 degrees Celsius , it was very important to keep the temp at this level for the bacteria(S. epidermidis and L. acidophilus) to grow. According to the Labpaq 37degrees Celsius is considered “average” temperature to grow bacteria (Mesophiles).
This method has been used in Britain in early 1842 by immersion in ice salt brine. It was widely used commercially after the advent of mechanical refrigeration. The process of freezing food starts by dropping the temperature of the product under 0 Celsius degrees to approximately -18 Celsius degrees which seals the nutritive value, taste and freshness of the food. For quality frozen products the aliments must be as fresh as possible and to be processed in a clean envoirment. Best frozen foods are meats, poultry, fish, bread and baked goods.
Name: Date: 17/02/2012 Lab Partner: TITLE: Specific heat capacity of copper INTRODUCTION: We are going to calculate the Specific heat capacity of copper, which means that we’re going to measure how much heat is needed to raise the temperature of 1kg of the substance for one Kelvin. If we know that the specific heat capacity of water is 4.18 kJ it’s possible to calculate the specific heat capacity of copper as well. The only required information we need is the mass and change in temperature both for water and copper. HYPOTHESIS Prediction: I think the specific heat capacity of copper will be pretty low compared to the water’s. Explanation: Because of copper is a good conductor compared to water because the electrons jump from one element to the other more easily in copper than water.
2011 P-DABC flexible job shop scheduling uses a crossover operator in the employed phase and external Pareto archive set [60] 5. 2010 GABC benchmark functions integrates global best information (gbest) into the solution search equation [61] 6. 2011 CABC Traveling Salesman integrates mutation operator in the employed and onlooker phase [62] 7. 2009 ABC quadratic knapsack uses heuristic to fix infeasible solution and local search for enhancement of exploration [63] 8. 2010 ABC quadratic minimum spanning tree uses tabu search to determine the new neighbouring food source [64] 9.