求翻译：4.强酸性 　　纯硫酸是无色油状液体，10.4°C时凝固。加热纯硫酸时，沸点290°C，并分解放出部分三氧化硫直至酸的浓度降到98.3%为止，这时硫酸为恒沸溶液，沸点338°C。无水硫酸体现酸性是给出质子的能力，纯硫酸仍然具有很强的酸性，98%硫酸与纯硫酸的酸性基本上没有差别，而溶解三氧化硫的发烟硫酸就是一种超酸体系了，酸性强于纯硫酸。 　　是什么意思？

4. strong acid pure sulfuric acid is a colorless oily liquid, while 10.4 ° c to set. When heating pure sulfuric acid, boiling point 290 ° c, and liberating part of sulfur trioxide up to acid concentration down to 98.3% point when sulfuric acid for the constant boiling solution, 338 ° c boiling point

4) strongly acidic pure sulfuric acid is a colorless oily liquid, at 10.4 degrees C concretion. When heating pure sulfuric acid, boiling point 290 degrees C liberation, and is divided into 3 parts for sulfur dioxide concentrations of the acid up to 98.3 % so far, this time for sulfuric acid, nitric

4. strong acid pure sulfuric acid is a colorless oily liquid, while 10.4 ° c to set. When heating pure sulfuric acid, boiling point 290 ° c, and liberating part of sulfur trioxide up to acid concentration down to 98.3% point when sulfuric acid for the constant boiling solution, 338 ° c boiling point