# Laboratory Techniques and Measurements Essay

824 Words Feb 26th, 2012 4 Pages
Laboratory Techniques and Measurements

Choose any three objects that are shorter than the metric ruler to measure, such as a CD, Key, spoon etc.

OBJECT | LENGTH (cm) | LENGHTH (mm) | ruler | 30.5 cm | 305 mm | thermometer | 15.1 cm | 151 mm | pencil | 16.7 cm | 167 mm |

Warm Temperature Measurements

* Fill a 100 a 100mL beaker with 50mL of hot water. Get the water as hot as possible. * Use thermometer to measure the temperature of the water in the beaker using Celsius unit. Record measurement in Data Below. * Place the beaker of the water on the wire gauze burner stand. * Remove the cap from the burner fuel and set aside. Light the fuel and slip it under the burner stand. * Bring the water to full
Data Table 3

Test tube (mL) | Number of drops in 1 mL | Pipet volume (mL) | 10 | 27 | 4 |

Mass Measurements

* Choose seven objects to measure. * Record the hypothesized mass of the first object. Record the measurement in Data Table 4. * Repeat the previous steps for each of the remaining objects. Did your hypotheses become more accurate with practice?
Data Table 4 Object | Estimated Mass (g) | Actual Mass (g) | pen | 7g | 5.7g | screw | 15g | 8.1g | cylinder | 18g | 16.5g | calculator | 310g | 255.4g | portable phone | 150g | 127.3g | Google | 62g | 53.6g | book | 450 | 485.3g |

Density Measurements

* Record all data table similar to Data 5 shown below. * Calculate the density of water.

Data Table 5

Hypothesis: The density of water greater than water

Data Table 5

| Mass A | Mass B | Mass A-B | | | Object | Graduated Cylinder+ Substance | Graduated Cylinder | Substance | Substance Volume | DensityM/V | Water | 24.6g | 16.5g | 8.1g | 5mL | 1.62 | Isopropyl alcohol | 24.3g | 16.5g | 7.8g | 5mL | 1.56 | Saturated salt | 25.6g | 16.5g | 9.1g | 5mL | 1.82 |

Density of irregular objects

* Calculate the density of a small, irregular metal object using the water-displacement method. Record the results in a Data table 6.

Data Table 6

| A | B | B-A | | | Object | Graduated Cylinder Volume | Graduated Cylinder + Object | Object Volume |