Empirical formula Lab

background [prelab assignment (20 points); due at the beginning of the lab]

1. in this lab, you will be given a sample of barium chloride hydrate [BaCl₂* 2 H₂O].  briefly, describe the experimental procedure to determine the # grams of Ba, Cl, and H₂O in the compound. (i.e. review the purpose & content of your lab report)

2. sketch a data table for your experimental measurements.

3. download / save the *. swf file (alternative source), then run the simulation using Ruffle to analyze simulated data using 2.0 g of sample to determine the empirical formula of copper oxide.

4. MSDS on silver nitrate

purpose

determine the empirical formula (including the # water molecules associated with metal chloride) based upon experimental data

compare results of using mass of filter paper before use to filter suspension versus after air dry precipitate in your calculations

materials

~ 1.5 g of barium chloride hydrate (or copper chloride hydrate)

balance; test tube; flask

hot plate

water;  30 mL 0.5 M silver nitrate

filter paper / funnel

methods / data analysis

student design

Content of lab report [35 points]

introduction  [10 points]

• purpose
• brief description of data analysis; include chemical basis

methods  [5 points]

• self-explanatory

results  [10 points]

• experimental data & determination of the empirical formula based on your data

discussion  [5 points]

• error analysis:   nontrivial error & subsequent effect (be specific) on determination of the empirical formula
• potential error due to mass of filter paper without precipitate - before filter suspension versus after air dry precipitate; support your conclusion based on experimental data

resources

heat suspension rationale