ALEKSZA
NHHS H-Chemistry
2013-14
Metric Measurements Activity
adapted from Berlin & Przygoda, MCC & Dr. Wilhelm, NHHS
Name:________________________________________________________Score:________/_ __
Partners:_______________________________________________________________________
_______________________________________________________________________________
Introduction:
The metric system of measurement is a nearly universal system which is decidedly less complex than
the English system used in this county. While the basic units of the English system refer to parts of a
king's body, the metric system is based on a fraction of the earth’s circumference. In addition, the
metric system is divisible by units of 10.
Purpose:
1. To gain familiarity with the basic metric units of length, weight, volume and temperature.
2. To gain an understanding of accuracy and precision and how these concepts apply to laboratory
experiments.
3. To learn that the average of the data collected is more significant to the lab than a single data
point.
4. To gain proficiency in the use of the following laboratory equipment:
 meter stick
 balances
 graduated glassware (cylinders, beakers, etc.)
 centigrade thermometers
Key Terms: meter, gram, liter, centigrade, tare weight gross weight, net weight, meniscus, precision
and accuracy.
Materials: Metric rulers, ring stands, buret clamps, straws, tape, paper plates, graduated cylinder,
buret, pipette, beakers, thermometers (digital and analog), water, calculators, electronic balance, triple
beam balance, weigh boats
Safety Concerns: Although all materials in this activity are considered non-hazardous, please use
normal laboratory precautions such as goggles and closed-toed shoes. There is a possibility of a broken
glass hazard.
A. Metric Measurement (5 pts total)
The prefixes for metric units are noted below.
A1. The base unit for length is the __________________. (1 point)
A2. The base unit for volume is the _________________. (1 point)
A3. The base unit for mass is the ___________________. (1 point)
A5. Define PERCISION –(1 pt)
A6. Define ACCURACY – (1pt)
B. Linear Measurement (11 points total)
B1. Javelin/Discus Throw (8 pts)
a.
b.
c.
d.
e.
f.
Stand on the tape placed on the floor of the lab area.
Gently toss a straw or paper plate in front of you.
Have a lab partner record the final location of the straw/plate.
Measure the distance (in meters and centimeter) covered by the straw/plate below.
Repeat steps a-d two more times
Calculate your average distance.
Javelin/Discus Distance1:________________________m ____________________________cm
Javelin/Discus Distance2:________________________m ____________________________cm
Javelin/Discus Distance3:________________________m ____________________________cm
Javelin/Discus Distance(AVG):______________________m
__________________________cm
B2. What do you conclude about your “javelin/discus” throwing ability (use scientific terms)?(3
pts)
C. Mass Measurement (17 points total)
C1. Define TARE WEIGHT – (1pt)
C2. Define GROSS WEIGHT – (1pt)
C3. Define NET WEIGHT – (1pt)
Identify the following laboratory items (1 pt each):
C4.__________________________
C5. __________________________
Identify the parts of the balance:
C6.
C7.
C8.
C9.
off
tare
C10.
Word Bank: Balance Pan, Dust Cover, Off Switch, On/tare/zero switch, digital display
C8. One-Hand Grab and Mass (7 pts)
1.
2.
3.
4.
5.
At the weigh station, use one hand to grab as many samples as you can.
Properly mass out your sample using the electronic balance. Record your data below.
Repeat your measurement using the triple beam balance. Record your data below.
Repeat steps 1-3 two additional times. Record your data below.
Calculate your average mass of samples grabbed.
Sample being tested:
Mass of
Samples
Grab #1
Grab #2
Grab #3
Average
C8b. What do you conclude about your “grabbing” skills from this activity? (3 pts)
D. Volumetric Measurement (36 points total)
D1. Define: MENISCUS (1pt)–
D2. Identify the samples of graduated laboratory equipment below: (1 pt each)
D2a________________
D2b__________________
D2c___________________
D2f._________________
Directions for reading graduated lab ware.
.
D2e___________________
Measuring Liquids: Accuracy & Precision (31 Points)
Adapted from Honors Chemistry- Dr. Wilhelm
Procedures:
D3. Graduated Cylinder
 Using the graduated cylinders at this station (10 mL, 25 ml, 50 or 100 ml), carefully measure 9
ml of the liquid (H2O). Circle the cylinder you used for the larger volume.
 Transfer the liquid to a weigh boat and record the mass (g) on the electronic balance.
 Remember to tare the balance to account for the mass of the weigh boat prior to measuring your
sample.
 Take triplicate measurements for each cylinder and find the average mass.
Cylinder
Mass (g)
Average (x)
10ml
25 ml
50 or 100ml
D4. Pipette
 Using the bulb syringe, draw in water to the pipette
 Carefully release the water to retain 9 mL.
 Transfer the 9mL to a weigh boat and record the mass.
 Repeat the procedure 2 more times and then find the average
Graduated Pipette
Mass (g)
Average (x)
9 ml
D5. Buret:
 Fill the burette with the liquid, then draw off enough liquid to fill the tip below the stopcock and
bring the level of the liquid down to scale.
 Withdraw 9mL of water directly into a weigh boat and record the mass.
 Repeat and record below
beret
9 ml
Mass (g)
Average (x)
Results
D6. Comparison of Five tools used to measure liquid volume (10 points – remember accuracy and
precisions!)
D7. Which tool was the most accurate for measuring 9 mL of liquid? Why? (3 pts)
D8. Which tool was the most precise for measuring 9 mL of liquid? Why? (3pts)
E. Thermal Measurement (18 points)
E1. Define FARENHEIT and Note at what temperature does water boil and freeze. (2pts) –
E2. Define CELCIUS and note at what temperature does water boil and freeze (2pt) –
E3. Define KELVIN – (1pt)
E4. Define RANKINE – (1 pt)
Temperature Conversion Equations
from Celsius
Fahrenheit
to Celsius
9
5
[°F] = [°C] × ⁄ + 32
[°C] = ([°F] − 32) × ⁄
Kelvin
[K] = [°C] + 273.15
[°C] = [K] − 273.15
Rankine
[°R] = ([°C] + 273.15) × ⁄
5
9
9
5
[°C] = ([°R] − 491.67) × ⁄
5
9
For temperature intervals rather than
specific temperatures,
1 °C = 1 K
and 1 ℃ = 1.8 °F
E6. Identify the following: (1 pt each)
E6a.__________________
E6b.___________________________
E7. Lab Water Temperature (10pts)
1. Obtain three 150ml or 250 ml beakers. Label beakers ROOM, COLD TAP and HOT TAP.
2. Fill each beaker ½ way with the type of water specified. (Run hot and cold taps for a minute or
two to get a more accurate temperature.
3. Take the temperatures of the water samples using the digital of thermometers and using both
Celsius and farenheit scales if available.
Digital (F)
Digital ( C )
Room Temp
Cold Tap
Warm Tap
E8a. Choose 1 of the samples and manually covert the temperatures from F (actual) to C
(calculated) and then one C(actual) to F (calculated). Show work! (5 pts)
E5b. COMPARE your calculated values to measured values. Note any discrepancies and a
probable cause. (3 pts)
OVERALL: What can you conclude about precision, accuracy and laboratory measurements
after conducting this activity? (5 points)