Experiment 1: Lab Techniques

Name:______Name: ______Date:______Experiment 1: Lab Techniques

Purpose: The purpose of this experiment is to familiarize yourself with some of the laboratory techniques that you will use throughout the semester.

Procedure: Part A: Filtering a Substance 1. Obtain a test tube from the test tube rack.

2. Add 30 drops of Pb(NO3)2 to the test tube.

3. Add 5 drops of K2CrO4 to the test tube. 4. Observe the reaction. Record your observations in the chart provided below. 5. Weigh an empty filter paper using an electronic balance and record this value in the data table provided below. Label your filter paper (near the outside edge) with your, or your partners, initials. 6. Set up for a filtration as demonstrated in class. 7. Filter out the solid (this is called the precipitate). 8. Carefully peel the sides of the filter paper away from the funnel and open it up so it lays flat. Be careful not to tear or lose any precipitate as this will affect your results. Place your filter paper in the designated area: ______9. Clean up – remember…clean glassware goes on the shelf, everything else goes in the drawer (except for test tubes/test tube rack – these are to be placed under the shelf)

Data table:

Observations:

Mass of filter paper Mass of filter paper plus solid ** Mass of solid **

** - will calculate tomorrow Part B: Using the Bunsen burner 1.) Take out your Bunsen burner and attach it to the jet. 2.) Turn on the gas valve and practice lighting the Bunsen burner and adjusting the air flow. Turn off the Bunsen burner when you are done practicing. 3.) Measure out 10 mL of the solution – this can be found at your lab table in a beaker labeled “solution.” (Think: what piece of lab equipment should you use to accurately measure out a small volume??) 4.) Set up a heating apparatus as demonstrated in class. Light the Bunsen burner only after you have completely set up your apparatus. 5.) Heat the solution until all of the water has evaporated; then turn off the Bunsen burner. 6.) Clean up – remember…hot glass looks the same as cold glass!!! Let your beaker cool for at least 10 minutes before emptying its contents in the trash can.

Questions: 1. In Part A, an insoluble solid was formed. What is this called?

2. Which elements make up the compound Pb(NO3)2 (use your periodic table in the back flap of your book to determine what each of these three symbols stand for)?

3. Which elements make up the compound K2CrO4? 4. In Part B, what solid do you think remained behind after all the water evaporated?