Chem 20L Winter 2003 Report Guideline for Experiment #5 (Detergent Experiment) Pre-lab is due at the beginning of the lab section. Refer to laboratory syllabus for the due date of the post-lab report. Pre-lab and Post-lab MUST be written inside your lab notebook (with the exception of graphs) (I) Pre-lab Guideline (I) Introduction (II) Procedure in Flowchart Format & reference of procedure (III) MSDS information (refer to the MSDS handout for details) The following chemicals will require you to use the MSDS database on the Web (see Lecture Syllabus): HCl (3M), NaOH (0.5M) and Phosphoric acid (H3PO4) (1M) Note: In MSDS, select the site that gives you the MSDS information closest to the concentration listed above for each individual chemical. You should record the following MSDS information in your notebook for the chemicals listed above. (Printouts directly from the Web pages will NOT be accepted!!) (a) Product Name (b) Chemical Formula (c) Formula Weight (d) Melting Point; Boiling Point and Density (e) Health Hazard Data (summarize in your own words) (f) Spill and Disposal procedures (summarize in your own words) (IV) Complete all the study questions # 1-3 on page 64. Follow instructions on p.64 (under "Pre-lab assignment") of your lab manual. (Make sure that you separate the blank data table with the rest of the prelab)Chem 20L Winter 2003 Report Guideline for Assignment 5 (Detergent Experiment) Post-lab MUST be written inside your lab notebook (with the exception of graphs) (II) Post-lab Guideline This is a GROUP report (i.e. ONE REPORT PER GROUP) (A) Data - write the responsibility of each group member during the experiment and in writing this report - recopy completed data tables (including the color change of the universal indicator) from your prelab to the postlab report (see p.65-66) - specific the unknown detergent label on your report (i.e. unknown C or unknown T) (B) Data and Error Analysis (MUST SHOW ALL WORK FOR FULL CREDIT) - calculate the % ashes left in the detergent (i.e. 100%*(weight of ashes / weight of sample detergent) ) - determine the volume of NaOH required to titrate one equivalent of the H2PO4- (refer to the chemical reaction shown on p.64) - calculate the equivalents of hydroxide that are required to titrate one equivalent of H2PO4- (this is the same as the number of equivalents of H+ transferred in the reaction (p.64)) - determine the equivalent weight of H2PO4- - using the equivalent weight of H2PO4- and the equivalents of H+ transferred in the reaction, calculate the amount (in grams) of H2PO4- in your detergent sample - calculate the weight (in grams) of the detergent that can be attributed to phosphate ( PO43- ) - determine the % phosphate in the original detergent sample - determine the % STPP in the detergent sample (C) Conclusions - summarize results - compare % phosphate in detergent with % ashes. What can you conclude?
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