Lab Equipment and Techniques

Used to weigh sodium chloride using the weigh by difference method.
To "eyeball" 1.0 g of sodium chloride, compare the sample vial with the TA's example.
Ensure the balance reading is zeroed before use.
Place the vial in the center, close the door and record all digits displayed.
Pour contents into a waste beaker after weighing and re-weigh the empty vial.

Used to transfer a specific volume of solution at a specific temperature (usually 20°C) with error under 0.2%.
Clean the pipette by rinsing 3 times with tap water, 3 times with DI water, and 3 times with the solution to be transferred.
Use a pipette bulb to draw the solution 2-3 cm above the graduation line.
Remove the bulb and use your index finger to control the flow, ensuring the meniscus aligns with the graduation line.
Touch the pipette tip to the receiving flask's inside wall; do not shake or blow out remaining solution.

Used to accurately transfer variable volumes of a solution.
Read from top-down to two decimal places by interpolating the last digit.
Clean the burette by rinsing 3 times with tap water, 3 times with deionized water, and 3 times with the solution to be transferred.
Fill the burette below eye-level and drain some solution to fill the tip and remove air bubbles.
Record the initial and final readings at eye level to avoid parallax error.
Calculate the aliquot volume as the difference of the final and initial readings.

Complete calculation includes formulas, full substitution of numbers with units, final answer rounded to the correct number of sig figs with units.
When carrying forward a calculated value, the reported number can include extra digits (if appropriate) but never too few.

Analytical balance: precise mass measurements less than ~200g.
Top-loading balance: mass measurements exceeding the analytical balance's capacity.
Volumetric pipette: single, fixed volume accurately to 2 decimal places.
Burette: variable volumes accurately to 2 decimal places.

Don't have to complete this experiment in order. Your TA will assign you to begin at either Part 1, 2, or 3 to avoid line ups for equipment.