∆ KClO3 (s) KCl (s) + O2 (g) 2 2 3 Purpose - Background - Lab17 Date: Percent of Oxygen in Potassium Chlorate Purpose - Experimentally determine the percentage of oxygen in KClO3. Background - ∆ KClO3 (s) KCl (s) + O2 (g) 2 2 3 MnO2 catalyst A catalyst speeds up a chemical reaction without changing chemically.

Actual Percent Composition

Experiment - Mass of test tube + small scoop of MnO2 = _______ g Mass of same test tube + small scoop of KClO3 = ____ g Mix KClO3 and MnO2. Heat test tube gently at first and then heat strongly for ~ 5 minutes or until O2 bubbling stops.

Perform a glowing splint test on the O2 collected. Keep heating until no more bubbles are produced in the tray Mass of cooled test tube after heating = _______ g Heat test tube again strongly for ~ 5 minutes to drive off any more O2. Mass of cooled test tube after 2nd heating = _______ g Throw product in trash, clean up.

Analysis - Calculate the mass of the KClO3 that you began with. Calculate the mass of the O2 that was removed by heating. Calculate the experimental percent of oxygen in the KClO3. Compare your experimental percent to the actual percent using percent error. Results -

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