LAB 1 – Biology Lab Skills

AP Biology—Lab 01
Complete the following conversions:
a. 0.167 mL to L _________
b. 0.05 mL to L _________
c. 42 L to mL _________
d. 182 L to mL _________
e. 0.9 L to mL _________
Identify four (4) important precautions in micropipette use:
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Procedure 8:
The accuracy of micropipette measurements
1. Using a 400 gram top-loading balance, tare a dry 250 mL beaker.
2. Using a large-range (100 L—1000 L) micropipette with a fresh tip, measure 1000 L
(1 mL) of de-ionized (DI) water.
3. Dispense this measured amount of water into the 250 mL beaker.
4. Record the mass of the water to the nearest 0.01 g in Table 8.
5. Tare the balance.
6. Again, using the large range micropipette, measure 10 mL of water and add it to the
250 mL beaker.
7. Record the mass in Table 8.
8. Repeat this procedure until you have 5 mL of water in the beaker on the balance.
9. Calculate the error columns in Table 8.
Table 8: Mass of water volumes measured using a large range (100 L—1000 L) micropipette.
Volume of
water (mL)
Calculated mass
of water added
in this step (g)
Measured mass
of water added
in this step (g)
Error
Percent Error
1.000
1.000
1.000
1.000
1.000
Mean
Values:
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