离子浓度大小的比较（Comparison of ion concentration）.doc

离子浓度大小的比较（Comparison of ion concentration） A comparison of the concentration of ions in a salt solution to the QQ bookmark: admin Click: 987 times The result is not ideal [national top teacher video tutoring high school curriculum] far title sea, near approach! High entrance, high two entrance, high three entrance A knowledge of ion concentration in salt solution is also compared to the size of the high school chemistry, a difficult, but as long as the master of the relevant knowledge, principle and law, combined with problem-solving skills, can you achieve the best effect of replication. I. Basic Knowledge There is a ionization balance of water in salt solution, and there may be salt hydrolysis and ionization balance, so there are the following relationships: 1.c (H +) and C (OH -) relationship: Neutral solution: C (H +) = C (OH -) (NaCl solution) Acid solution: C (H +) C (OH -) (e.g., NH4Cl solution) Alkaline solution: C (H +) C (OH -) (Na2CO3 solution) Constant temperature: C (H+) - C (OH -) = fixed value (10-14 at normal temperature) 2. charge conservation: salt solution of anions and cations in the electric charge equal to the total. Such as NH4Cl solution: C (NH4+) + C (H+) = C (Cl -) + C (OH -) Such as: Na2CO3 solution c (Na+) C (H+) = 2C (CO32-) C (HCO3-) C (OH -) 3. conservation of matter: an element of various forms of particles, the sum of the total amount of matter unchanged. Such as the 0.1 mol/L NH4Cl solution: C (NH4+) C (NH3, H2O) = 0.1 mol/L Such as the 0.1 mol/L Na2CO3 solution: C (CO32-) C (HCO3-) C (H2CO3) = 0.1 mol/L Two, problem-solving methods and steps 1. which is the main reason for hydrolysis or ionization?. (1) hydrolysis of salt ions is not ionization: strong acid, alkali, salt, such as NaCl, Na2SO4 and so on. (2) salt ion hydrolysis without ionization of weak acid or alkaline acid: the formation of alkali salt, such as NH4Cl, Na2CO3 etc.. (3) salt ions both hydrolysis and ionizing: polybasic acid formed by hydrolysis of acid salt, NaHC