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酸式盐的性质是中学化学教学的重点和难点,其中有不少问题常被人们所忽视。本文拟运用电离理论、离子极化理论以及体系的自由能变化,来探讨有关酸式盐性质的一些问题。希望能对深刻理解中学化学教材,避免命题中的科学性错误有一定帮助。下面从五个方面加以讨论。一、弱酸的酸式盐的酸碱两重性强酸的酸式盐,如NaHSO_4,仅能与碱反应,它可以认为是中和反应的继续。而弱酸的酸式盐(如Na_2HPO_4),既能与强酸反应,生成相应的弱酸(H_3PO_4)或含H~+更多的酸式盐(NaH_2PO_4);又能与强碱反应(如NaH_2PO_4),生成其正盐(Na_3PO_4)或含H~+更少的酸式盐(Na_2HPO_4)。对于NaHCO_3与酸的反应:
The nature of acid salts is the focus and difficulty of chemistry teaching in middle school, many of which are often neglected by people. This article intends to use ionization theory, ion polarization theory and the system of free energy changes, to explore some of the nature of acid salt problems. Hope to have a good understanding of the chemistry textbook of middle school and avoid the scientific mistakes in the proposition. The following five aspects to be discussed. Acid-base duality of acid salts of weak acids Acidic salts of strong acids, such as NaHSO 4, react only with bases, which can be considered as the continuation of the neutralization reaction. Acidic salts of weak acids (such as Na 2 HPO 4) react with strong acids to form corresponding weak acids (H 3 PO 4) or acid salts (H 2 PO 4) with more H 2 + ions and react with strong bases (such as NaH 2 PO 4) Generate its normal salt (Na_3PO_4) or contains less H_ acid salt (Na_2HPO_4). For the reaction of NaHCO 3 with acids: