三さん酸さん化か硫黄いおうMeaningsNoun1. sulfur trioxide (SO3)Kanji used三three酸acid化transformation硫sulphur黄yellowPitch accentさんさんかいおうComposed of三さんthree; 3Numeric酸さん化かoxidation; oxidizationNoun硫黄いおうsulfur (S); sulphurNoun