CHEM1100: Laboratory Techniques & Measurements Lab (HOL)
#34 - Place the pen or pencil on the scale to measure the mass of the object. Record the mass in Data Table 3 under "Actual Mass (g)." #35 - Repeat steps 33 and 34 for the remaining object(s) in Data Table 3.
Actual Mass (g): pen or pencil: 4.32 3 pennies: 7.48 1 quarter: 5.59 2 quarters, 3 dimes: 17.93 4 dimes, 5 pennies: 22.01 3 quarters, 1 dime, 5 pennies: 31.82 Key: 9.23 key, 1 quarter, 4 pennies: 26.12
#10 - Allow the water to continue boiling for approximately 5 minutes. After 5 minutes, measure the temperature with the thermometer in degrees Celsius (°C) to the correct level of precision. Record the measurement in Data Table 2.
Boiling 5 mins: 98.0C, 208F, 371K
#4 - Measure the temperature of the hot tap water with the thermometer in degrees Celsius (°C) to the correct precision of the thermometer. Record the measurement in Data Table 2.
Hot tap: 55.0C, 131F, 328K
#32 - Estimate the masses for each of the object(s) in grams and record in Data Table 3. To help you with this process, a penny has a mass of approximately 2.5 grams.
Estimated mass (g): pen or pencil: 5.00 3 pennies: 7.00 1 quarter: 5.00 2 quarters, 3 dimes: 18.5 4 dimes, 5 pennies: 20.0 3 quarters, 1 dime, 5 pennies: 26.0 Key: 10.0 key, 1 quarter, 4 pennies: 24.0
#26 - Convert the temperature measurements for each of the 6 water samples from °C to °F and K. Record the converted temperatures in Data Table 2.
Hot tap: 55.0C, 131F, 328K boiling: 100.0C, 212.0F, 373.2K Boiling 5 mins: 98.0C, 208F, 371K cold tap: 22.0C, 71.6F, 295K Ice water 1 min: 10.0C, 50.0F, 283K ice water 4 mins: 2.0C, 36F, 275K
#22 - Measure the temperature of the ice water after 1 minute with the thermometer in degrees Celsius (°C) to the correct level of precision. Record the measurement in Data Table 2.
Ice water 1 min: 10.0C, 50.0F, 283K
Exercise 2 - Questions Question 1: A student was given an unknown metal. The student determined that the mass of the metal was 30.2 g. The student placed the metal in a graduated cylinder filled with 20.0 mL of water. The metal increased the volume of water to 22.9 mL. Calculate the density of the metal and determine the identity of the metal using the table below.
Mass: 30.2g (vol of metal = Vol of metal and water - vol of water) 22.9-20.0=2.9mL (volume of metal) (density of metal = mass/ volume) 30.2g/2.9g = 10.41g/mL (density of metal) metal is Ag (silver)
#5 - Allow the water to heat unit it comes to a full boil. As soon as the water is boiling fully, measure the temperature with the thermometer in degrees Celsius (°C), to the correct level of precision. Record the measurement in Data Table 2.
boiling: 100.0C, 212.0F, 373.2K
#19 - Measure the temperature of the cold tap water with the thermometer in degrees Celsius (°C) to the correct level of precision. Record the measurement in Data Table 2.
cold tap: 22.0C, 71.6F, 295K
#25 - Measure the temperature of the ice water after 4 minutes with the thermometer in degrees Celsius (°C) to the correct level of precision. Record the measurement in Data Table 2.
ice water 4 mins: 2.0C, 36F, 275K
#36 - For each object(s), convert the actual mass (in grams) to kilograms (kg). Record in Data Table 3.
Convert actual mass (g) to Kg: pen or pencil: 0.152 3 pennies: 0.005 1 quarter: 0.006 2 quarters, 3 dimes: 0.0179 4 dimes, 5 pennies: 0.0220 3 quarters, 1 dime, 5 pennies: 0.0318 Key: 0.009 key, 1 quarter, 4 pennies: 0.0261
Experiment 1: #3 - Measure the length of each of the following objects (CD or DVD, Key, Spoon, Fork) with the ruler in centimeters (cm) to the correct level of precision and record in Data Table 1.
DVD: 12.3 cm, 123mm, 0.123m Key: 5.35cm, 53.5mm, 0.0535m spoon: 15.4cm, 154mm, 0.154m fork: 17.6cm, 176mm, 0.176m
Experiment question: While heating a sample of ethanol, it boils at 76.1°C. Calculate the percent error from the theoretical 78.4°C. (Show all your calculation work and label your answer.)
E - T/T x 100 76.1 - 78.4/ 78.4 x 100 = -2.93367 answer: 2.93367% (not sure if you need to round but if you do id say 2.93%)
