: Laboratory Techniques & Measurements

OBJECTIVES: 1. To become familiar with several important laboratory techniques 2. To gain proficiency with some of the common measuring devices used in a chemistry laboratory 3. To determine the volume and density of objects (Jeschofnig, n.d.)

DATA AND OBSERVATIONS:
Length and Measurements

Our three objects that we measured with the metric ruler were Polly Pocket (9cm/9mm), a Ted Baker Glasses Case (15.3cm/153mm), and a small pencil (2.5cm/25mm) (See Table 1).

Table 1. Showing three objects measured in both centimeters (blue) and millimeters (dark pink).

Warm Temperature Measurements

A 100mL glass beaker was filled with 50 mL of hot tap water and the temperature recorded was 35⁰C. The water was then poured into a pot, placed on the stove, brought to a boil, and the temperature recorded was 98⁰C. Next, the water continued to boil for five minutes and the temperature remained the same at 98⁰C (See Table 2.).

Table 2. Warm Temperature in Celsius Measurements.
Cold Temperature Measurements

A 100mL glass beaker was filled with cold tap water and the temperature recorded was 15⁰C. We then reduced the water in the beaker to 50mL of cold tap water and introduced ice to bring the volume near the top of the glass beaker. The water-ice mixture was gently stirred with a glass thermometer and the temperature recorded was -1⁰C (See Table 3).

Table 3. Cold Temperature Measurements.

Volume Measurements See Figure 1 for the sketch of our meniscus in our 25 mL plastic graduated cylinder with 12.5 mL of tap water in it. We filled a small glass test tube with tap water, poured it into the graduated cylinder, and the volume recorded was 22.5 mL.
We determined the volume of the thin-stemmed micropipette by filling the micropipette with tap water and counting the drops as they fell into the graduated cylinder. We counted 34