A 8.68g sample containing solid potassium chlorate and other inert impurities was heated in test tube. the potassiumchlorate in the sample completely decomposed into potassiumchloride and oxygen gas. The oxygen produced was collected overwater at 21 degree celcius when the atmospheric pressure was 758.4torr. The volume of the gas collected was 0.667 liters. the vaporpressure waster 21 degree celcius is 18.65 torr. calculate the percent purity of potassium chlorate in the original sample.