Question

Need to find percent by mass of K and Cl combined in KClO3 and the rest. thanks!

SAFETY PRECAUTIONS BEYOND STANDARD PROCEDURES CAUTION! Potassium chlorate is a strong oxidizing agent and may cause fires or explosions if mixed or heated with combustible materials. Observe the following safety precautions when working with potassium chlorate. Heat samples slowly and carefully to avoid spills and spattering. Check before disposing of potassium chlorate residue. Dispose of solutions containing silver in aqueous waste. PART A: DETERMINING PERCENT COMPOSITION 1. Place a clean, dry crucible on a clay triangle and heat for 2-3 minutes at the maximum flame temperature. 2. Allow the crucible to cool, and weigh the crucible and cover. 3. Add between 1 and 1.5 grams of Kao, and weigh again. 4. Place the covered crucible on the clay triangle and heat gently for 8 minutes. This is best accomplished by moving the burner in and out from under the crucible. 5. Heat the crucible more vigorously for 10 minutes by placing the top of the bright, blue cone of the burner so that it touches the bottom of the crucible. The bottom of the crucible should be heated to a dull, red color. 6. Remove the crucible from the wire triang sing the crucible tongs. Let the crucible cool and weighit. 7. After weighing, heat the sample for an additional 6 minutes at the maximum flame temperature.; cool and reweigh. 8. The last two mass determinations should agree. If they are not within 0.05 g of each other then repeat the heating and weighing until two agree within the specified tolerance (0.05 9). PART B: QUALITATIVE EXAMINATION OF RESIDUE This part of the experiment should be started as soon as the final heating and weighing of the first sample is completed. 1. Number and place three clean test tubes in a beaker. 2. Place a pea-sized quantity of KCl into tube no. 1, a pea-sized quantity of KCIO, in tube no. Arst a 3. Add approximately 10 mL of distilled water to each of the test tubes. 93

there is no information about AgCl

Answer 1

& Percent by mass of K and ce combined in kaloz mass of residu To tal mass - 0.603 x 100 = 49.67 *100 1.214 - Theoritical of. by mass of kand ce in Keloz = atomic mass of K + atomic mass of a yoo molar mass of kuloz 39.098 + 35.453 x doo Taas 60.85 & %o errara theoretical - Experimental you Thearitical 6o 68 - 49.67x100 60.85 = 18.37°/ errar