Click hereto get an answer to your question ️ Calculate the mass of potassium chlorate required to liberate 6.72 dm^3 of oxygen at STP. When heated, a $3.40\ \mathrm g$ sample mixture of $\ce{KClO3}$ decomposes and produces $685\ \mathrm{cm^3}$ $\ce{O2}$ gas at $30\ \mathrm{^\circ C}$ and $101\ \mathrm{kPa}$. Molecular weight calculation: 39.0983 + 35.453 ›› Percent composition by element In SI, the unit for molar mass is kg/mol. [Molar mass of potassium chlorate is 122.5 g/mol]. Show your work clearly. If a drop of a solution of sulfur dioxide in ether or alcohol is added to powdered potassium chlorate, the mass explodes [Mellor 2:311. The formula weight is simply the weight in atomic mass units of all the atoms in a given formula. We use the most common isotopes. Potassium Chlorate KClO3 Molar Mass, Molecular Weight. Potassium Chloride KCl Molar Mass, Molecular Weight. If your reaction ends up producing less oxygen than predicted, you can calculate its percent yield by using and δ (the molar mass of potassium chlorate) to determine the mass of potassium chlorate present in the original mixture (this is the KClO 3 that decomposed in this experiment and is represented by λ, below, in the equation.) • HClO3 + KOH = H2O + KClO3 • NH4Cl + KOH = NH3 + H2O + KCl The equation to use: 7. Show your work! The answer is rounded to four sig figs, the number of sig figs you have for the mass of potassium chlorate. The molar mass and molecular weight of KClO3(S) is 154.6145. \[\text{Mass Percent of Oxygen (experimental)} = \frac{ \text{Mass of Oxygen Released}}{ \text{Mass of Potassium Chlorate Used}} \times 100\] Mass percentages of elements in compounds can also be theoretically calculated using molar masses, along with the known chemical formula of the compound. The Composition of Potassium Chlorate Part A: Mass Percent of Oxygen in Potassium Chlorate Experimental Data Sample 1 Sample 2 (a) Mass of crucible + lid ... • Using molar masses along with the known formula of potassium chlorate, calculate the theoretical mass percent of oxygen in KClO3. What is the mass …