温度对水中碳酸平衡的影响浅析

Temperature effect on carbonic acid balance in water

本文通过理论分析和计算探讨了0~100℃范围内不同温度下的碳酸平衡问题,分析了H2CO3＊、HCO3-和CO32-三种碳酸在不同温度和pH条件下的水中所占比例及分布规律。认为0~100℃范围内pH0在8.60~8.22之间变化,变化范围较小;三种碳酸在不同温度下随pH变化过程中所占比例存在差异,但差异也不大;在0~100℃范围内不管温度高低,均表现出酸性水中H2CO3＊占优势,碱性水中CO32-占优势,偏酸、偏碱及中性水中HCO3-占优势;在较低pH下由于水中CO32-含量很少,因此用常规方法一般是难以检测到的。

Carbonic acid balance at 0~100 ℃ is studied based on theoretical analysis and calculation.Proportion and distribution of H2CO3＊,HCO3-and CO32-in water at different temperature and pH value are elucidated.It is believed that the pH0 ranges slight,between 8.60~8.22 within 0~100 ℃,and that the proportion of three carbonates accounting for different ratios with the changes of the pH,but the difference is small.At any temperature between 0 ℃ and 100℃,H2CO3＊ dominates in acidic water,while CO32-in alkaline water and HCO3-in low acidic,low alkaline and neutral water.It is difficult for CO32-determination with traditional method for its low concentration under low pH value.